Civil Technical Specifications - Shire of Dandaragan · Civil Technical Specifications Sewer Infill...

Civil Technical Specifications CW962500-CI-SP-001

Revision: 0 Date: 30/08/16

Prepared for:

Shire of Dandaragan

Sewer Infill Expansion

Jurien Bay

RFT 01/2016

QM

-PN

-002-1

Appendix C

Civil Technical Specifications Sewer Infill Expansion

Shire of Dandaragan

CW962500-CI-SP-001-Civil Technical Specifications-1.docm of 47

Contact Information

Cardno BEC Pty Ltd

Trading as Cardno BEC

ABN 66 074 006 063

Cardno WA Pty Ltd

Trading as Cardno

ABN 77 009 119 000

11 Harvest Terrace, West Perth WA 6005

Telephone: 08 9273 3888

Facsimile: 08 9486 8664

International: +61 8 9273 3888

[email protected]

www.cardno.com

Document Information

Prepared for Shire of Dandaragan

Project Name Sewer Infill Expansion

Site Location Jurien Bay

Client Reference RFT 01/2016

Project No CW962500

Discipline Code CI

Doc Type Code SP

Doc Sequence No 001

Doc Title Civil Technical Specifications

Revision Number 0

Effective Date 30/08/16

Date Approved 30/08/16

Document Control

Rev

isio

n Date Description of Revision Prepared

By Reviewed By

Approved By

0 30/08/16 Initial Revision Steven J Hecker Neville Taito NT

© Cardno. Copyright in the whole and every part of this document belongs to Cardno and may not be used, sold, transferred, copied or reproduced in whole or in part in any manner or form or in or on any media to any person other than by agreement with Cardno.

This document is produced by Cardno solely for the benefit and use by the client in accordance with the terms of the engagement. Cardno does not and shall not assume any responsibility or liability whatsoever to any third party arising out of any use or reliance by any third party on the content of this document.

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Table of Contents

1 GENERAL REQUIREMENTS .................................................................................................................. 7

1.1 Existing works ................................................................................................................................ 7

1.1.1 General ........................................................................................................................................... 7

1.1.2 Existing Services ............................................................................................................................ 7

1.1.3 Work in Public Roads ..................................................................................................................... 7

1.2 Materials, plant & workmanship ..................................................................................................... 8

1.2.1 General ........................................................................................................................................... 8

1.2.2 Samples and Testing Materials ...................................................................................................... 8

1.2.3 Regulatory Bodies .......................................................................................................................... 9

1.2.4 Permits ........................................................................................................................................... 9

1.3 As constructed information ............................................................................................................. 9

1.4 Public liaison standards ................................................................................................................. 9

1.5 Site Facilities ................................................................................................................................ 10

1.5.1 Power & Water ............................................................................................................................. 10

1.5.2 Medical Services .......................................................................................................................... 10

1.5.3 Location of Compound ................................................................................................................. 10

1.5.4 Site Office ..................................................................................................................................... 10

1.5.5 Contractor’s Telephone Contact .................................................................................................. 10

1.6 Public protection against vibration and damage .......................................................................... 10

1.6.1 Pre-inspection of Buildings/Residences ....................................................................................... 10

1.6.2 Vibration Monitoring ..................................................................................................................... 11

1.7 Movement through private property ............................................................................................. 11

1.8 Site meeting requirements ........................................................................................................... 11

1.9 Proprietary products or brands ..................................................................................................... 11

1.10 Dewatering and disposal of dewatered products ......................................................................... 11

1.11 Safety ........................................................................................................................................... 12

1.11.1 General ......................................................................................................................................... 12

1.11.2 Occupational Safety and Health Management Plan .................................................................... 12

1.11.3 First Aid ........................................................................................................................................ 12

1.11.4 Unexploded Ordinances ................................................................ Error! Bookmark not defined.

1.11.5 Excavations .................................................................................................................................. 13

1.11.6 Access Chambers/Pumping Station Openings ............................................................................ 14

1.11.7 Pumping Station Excavations and Microtunnelling Pits ............................................................... 14

1.11.8 Laser Safety Officer ..................................................................................................................... 14

1.11.9 Temporary Facilities/Resident’s Access ...................................................................................... 14

1.11.10 Employee’s Pets and Non-work Related Visitors ................................................................... 14

1.11.11 Public Safety at Construction Sites – S152 ............................................................................ 14

1.11.12 Personal Protective Equipment (PPE) – S22 ......................................................................... 15

1.11.13 Clearance to Work on Water Corporation Assets - WC-OSH -23 .......................................... 15

1.11.14 Quick-Hitch Assemblies ......................................................................................................... 15

1.11.15 Fall Prevention ....................................................................................................................... 15

1.11.16 Gas Testing and Confined Space Entry - WC-OSH-108. ...................................................... 15

1.12 Flammable liquid installations ...................................................................................................... 15

1.13 Environmental protection ............................................................................................................. 15

1.13.1 Dust Control ................................................................................................................................. 15

1.13.2 Noise Control................................................................................................................................ 16

1.13.3 Disposal of Rubbish, Cleared Vegetation, etc. ............................................................................ 16

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1.13.4 Removal of Unsuitable Material and Spoil (including ASS) ......................................................... 16

1.13.5 Contamination of the Site ............................................................................................................. 16

1.13.6 Flora Conservation ....................................................................................................................... 16

1.13.7 Aboriginal Heritage Sites .............................................................................................................. 17

1.14 Sand drift ...................................................................................................................................... 17

1.15 Notice of commencement of sewer works and notice of entry .................................................... 17

1.15.1 Notice of Commencement of Works ............................................................................................ 18

1.15.2 Notice of Entry .............................................................................................................................. 18

1.15.3 Boundary fence relocation ........................................................................................................... 18

1.16 Planning requirements ................................................................................................................. 19

1.16.1 General ......................................................................................................................................... 19

1.17 Clearance to work (CTW) requirements ...................................................................................... 19

2 SITE PREPARATION AND EARTHWORKS ........................................................................................ 20

2.1 Clearing and grubbing .................................................................................................................. 20

2.1.1 General ......................................................................................................................................... 20

2.1.2 Protection of Trees ....................................................................................................................... 20

2.2 Topsoil .......................................................................................................................................... 20

2.3 Earthworks .................................................................................... Error! Bookmark not defined.

2.3.1 Surface Finish ............................................................................... Error! Bookmark not defined.

2.3.2 Cuttings ......................................................................................... Error! Bookmark not defined.

2.3.3 Embankments ............................................................................... Error! Bookmark not defined.

2.4 Disposal of surplus soil ................................................................................................................ 21

2.5 Payment for earthworks ................................................................ Error! Bookmark not defined.

2.6 Rock excavation ........................................................................................................................... 21

2.6.1 Rock Blasting ............................................................................................................................... 22

2.6.2 Rock in Lots................................................................................... Error! Bookmark not defined.

2.7 Testing ........................................................................................... Error! Bookmark not defined.

3 PAVEMENTS ......................................................................................................................................... 23

3.1 General ......................................................................................................................................... 23

3.2 Material ......................................................................................................................................... 23

3.2.1 Testing .......................................................................................................................................... 23

3.3 Subgrade ...................................................................................................................................... 23

3.3.1 Sub-base ...................................................................................................................................... 24

3.4 Base course ................................................................................................................................. 25

3.5 Priming of Pavement .................................................................................................................... 26

3.6 Blinding ......................................................................................................................................... 27

3.7 Wearing course ............................................................................................................................ 27

3.7.1 Tack Coat ..................................................................................................................................... 29

3.7.2 Placing the Mixture ....................................................................................................................... 29

3.7.3 Compaction of Mixture ................................................................................................................. 30

3.7.4 Opening to traffic .......................................................................................................................... 31

3.8 Concrete kerbs ............................................................................................................................. 31

3.9 Road furniture................................................................................ Error! Bookmark not defined.

3.9.1 Street Signs ................................................................................... Error! Bookmark not defined.

3.9.2 Barrier Posts.................................................................................. Error! Bookmark not defined.

3.10 Survey Checks ............................................................................................................................. 32

3.11 Clean Up ...................................................................................................................................... 32

4 PATHWAYS ................................................................................................ Error! Bookmark not defined.

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4.1 General .......................................................................................... Error! Bookmark not defined.

4.2 Clearing ......................................................................................... Error! Bookmark not defined.

4.3 Subgrade ....................................................................................... Error! Bookmark not defined.

4.4 Cast Insitu Concrete Paths ........................................................... Error! Bookmark not defined.

4.4.1 Dimensions .................................................................................... Error! Bookmark not defined.

4.4.2 Sand Bedding ................................................................................ Error! Bookmark not defined.

4.4.3 Construction .................................................................................. Error! Bookmark not defined.

4.4.4 Forming ......................................................................................... Error! Bookmark not defined.

4.4.5 Grade and Alignment .................................................................... Error! Bookmark not defined.

4.4.6 Optional Requirements ................................................................. Error! Bookmark not defined.

4.5 Multi-Use Trails ............................................................................. Error! Bookmark not defined.

4.6 Materials ........................................................................................ Error! Bookmark not defined.

4.6.1 Concrete ........................................................................................ Error! Bookmark not defined.

4.7 Placing and Finishing .................................................................... Error! Bookmark not defined.

4.7.1 General .......................................................................................... Error! Bookmark not defined.

4.7.2 Strike Off Consolidation and Finishing .......................................... Error! Bookmark not defined.

4.7.3 Joints ............................................................................................. Error! Bookmark not defined.

4.8 Curing ............................................................................................ Error! Bookmark not defined.


4.8.2 Moist Curing .................................................................................. Error! Bookmark not defined.

4.8.3 Waterproof Paper - Polythene Sheeting ....................................... Error! Bookmark not defined.

4.8.4 Liquid Membrane Compounds ...................................................... Error! Bookmark not defined.

4.8.5 Stripping of Edge Forms ............................................................... Error! Bookmark not defined.

4.9 Protection of Pavements and Works ............................................. Error! Bookmark not defined.

4.9.1 Pavements .................................................................................... Error! Bookmark not defined.

4.9.2 Protection of Works ....................................................................... Error! Bookmark not defined.

4.9.3 Protection Against Weather .......................................................... Error! Bookmark not defined.

4.10 Testing and Acceptance Requirements ........................................ Error! Bookmark not defined.

4.10.1 Tolerances ..................................................................................... Error! Bookmark not defined.

4.10.2 Test Specimen .............................................................................. Error! Bookmark not defined.

4.11 Clean Up and Backfilling ............................................................... Error! Bookmark not defined.

5 TRENCHING .......................................................................................................................................... 33

5.1 Excavation .................................................................................................................................... 33

5.2 Pipe bedding ................................................................................................................................ 34

5.3 Backfilling ..................................................................................................................................... 34

5.4 Basis of measurement ................................................................................................................. 35

6 GRAVITY SEWERS ............................................................................................................................... 36

6.1 General ......................................................................................................................................... 36

6.2 Excavation and backfilling ............................................................................................................ 36

6.3 Trenchless Techniques ................................................................................................................ 36

6.4 Materials ....................................................................................................................................... 37

6.5 Bedding ........................................................................................................................................ 37

6.6 Junctions ...................................................................................................................................... 37

6.7 Access chambers ......................................................................................................................... 37

6.8 Location of property connections ................................................................................................. 38

6.9 Concrete encasements ................................................................................................................ 38

6.10 Testing, tolerances and as-constructed ....................................................................................... 39

6.10.1 Hydrostatic Testing of Upvc Sewers and Property Connections ................................................. 39

6.10.2 Air Testing of uPVC Sewers and Property Connections .............................................................. 39

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6.10.3 Hydrostatic Testing of Concrete Sewers ...................................................................................... 39

6.10.4 Ovality Testing of Concrete Sewers ............................................................................................. 40

6.10.5 Sewer Test Failure ....................................................................................................................... 40

7 CONCRETE & MORTAR WORK .......................................................................................................... 41

7.1 Materials ....................................................................................................................................... 41

7.1.1 Concrete ....................................................................................................................................... 41

7.1.2 Cement ......................................................................................................................................... 41

7.1.3 Aggregate ..................................................................................................................................... 41

7.1.4 Water ............................................................................................................................................ 41

7.1.5 Sand ............................................................................................................................................. 41

7.1.6 Steel ............................................................................................................................................. 42

7.2 Mixing and placing ....................................................................................................................... 42

7.3 Curing ........................................................................................................................................... 43

7.4 Finish ............................................................................................................................................ 43

7.5 Formwork ..................................................................................................................................... 43

7.6 Reinforcement .............................................................................................................................. 44

7.7 Testing .......................................................................................................................................... 44

7.8 Mortar ........................................................................................................................................... 45

8 STONEWORK ............................................................................................. Error! Bookmark not defined.

8.1 General .......................................................................................... Error! Bookmark not defined.

8.2 Limestone ...................................................................................... Error! Bookmark not defined.

8.3 Mortars .......................................................................................... Error! Bookmark not defined.


8.3.2 Materials for mortar ....................................................................... Error! Bookmark not defined.

8.3.3 Admixtures .................................................................................... Error! Bookmark not defined.

8.3.4 Mortar Mixing................................................................................. Error! Bookmark not defined.

8.3.5 Coloured Mortar ............................................................................ Error! Bookmark not defined.

8.4 Aggregate weep drains ................................................................. Error! Bookmark not defined.

8.5 Workmanship ................................................................................ Error! Bookmark not defined.

8.6 Stone pitching................................................................................ Error! Bookmark not defined.

8.7 Cleaning ........................................................................................ Error! Bookmark not defined.

8.8 Protection of finished work ............................................................ Error! Bookmark not defined.

9 UNDERGROUND ELECTRICITY ............................................................... Error! Bookmark not defined.

9.1 Introduction .................................................................................... Error! Bookmark not defined.

9.2 Duct Installation ............................................................................. Error! Bookmark not defined.

9.3 Substation & Transformer Sites .................................................... Error! Bookmark not defined.

10 QUALITY ASSURANCE ........................................................................................................................ 46

10.1 General ......................................................................................................................................... 46

10.2 Traceability ................................................................................................................................... 46

10.3 Inspection ..................................................................................................................................... 46

10.4 Conformance testing .................................................................................................................... 46

10.4.1 Testing Personnel ........................................................................................................................ 46

10.4.2 Submission of QA Certificates/Test Results ................................................................................ 47

10.4.3 Sampling and Test Frequency ..................................................................................................... 47

10.4.4 Records and Reporting ................................................................................................................ 47

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1 GENERAL REQUIREMENTS

1.1 Existing works

1.1.1 General

Where works are continuous with or adjacent to existing work, the Contractor is responsible

for making the proper junction between the two sections and for making good any damage to

the adjoining works. The Contractor shall confirm that the existing works conform in level and

location with those shown on the Drawings before commencing any work on site. No claim

shall be considered consequent upon the Contractor failing to ensure that this condition is met.

1.1.2 Existing Services

The Contractor is required to make enquiries to all Public Utility Authorities and determine the

location of all services in the work area.

The Contractor shall take all precautions necessary to prevent damage to existing fencing,

drainage structures, telephone and power lines, water mains and services, and/or other

improvements during the construction period. Any damage caused by the Contractor shall be

made good by the Contractor at the expense of the Contractor, or the Superintendent shall

arrange for such damage to be made good by others and for the costs involved to be deducted

from payments due to the Contractor. It is the Contractor’s responsibility to establish what

services or improvements exist or are under construction at the works site.

Any damage caused by the Contractor shall be notified immediately to the Superintendent and

to the Authorities or persons concerned.

1.1.3 Work in Public Roads

The use of public roads, the points of access to and crossings of public roads shall be

minimised. Where public roads are used, the Contractor shall maintain these roads free of

any earth, rock or other materials which may fall from the Contractor’s plant. All such material

dropped on to public roads shall be promptly removed, the roads cleaned, and any damage

caused made good to the satisfaction of the Superintendent and the Authorities concerned

without additional charge.

All works in public roads shall be carried out with proper concern to the safety of the public at

all times. The Contractor shall be responsible to install and maintain necessary temporary

signage, lighting and barricading to protect and secure all works throughout the course of the

Contract. The Superintendent may instruct the suspension of the works at the Contractor’s

cost if these requirements are not satisfactorily addressed.

The Contractor shall be required to issue all residents affected by the proposed works with

written notification, setting out the timing of the works, advising details of any disruption, and

confirming that reinstatements will be promptly addressed. This notification shall be issued at

least 5 days before commencing the works in question. The Superintendent may instruct the

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suspension of the works at the Contractor’s cost if these requirements are not satisfactorily

addressed.

Where pedestrian routes are disrupted by the works, the Contractor shall construct and

maintain temporary routes around the affected areas. The Superintendent may instruct the

suspension of the works at the Contractor’s cost if these requirements are not satisfactorily

addressed.

When working in developed verges, the Contractor shall cut out turf (as sods) in areas affected

by the works, store, preserve, and carefully relay the turf to line and level at the completion of

the works. Where the existing turf cannot be preserved and relaid, the Contractor shall allow

to lay new turf to match the existing condition. Irrigation systems shall be maintained, but if

damaged, shall be repaired immediately by the Contractor, at his expense. Where necessary,

the Contractor shall modify existing irrigation systems to suit the new extent of verge created

by the works.

Open excavation across property crossovers shall be undertaken with the consent of the

affected resident, and shall be made trafficable again within 3 hours of being excavated.

Verge areas and crossovers shall be fully reinstated within 48 hours of completing works in

the particular location.

1.2 Materials, plant & workmanship

1.2.1 General

Unless otherwise specified, materials and plant shall be new, the best of their respective kinds

and conforming with relevant standard specifications and codes issued by the Standards

Association of Australia. Where such Australian Standards (A.S.) do not exist, the relevant

British Standard Specification (B.S.S.) where such exist, shall apply unless otherwise

specified.

Workmanship shall be the best of its respective kind and conform with the best practices of

the trade.

1.2.2 Samples and Testing Materials

The Contractor shall submit samples of materials and test results of samples. Tests shall be

carried out as the work progresses to ensure that construction conforms to the requirements

of this Specification.

Where test results are called for in this Specification, the Contractor shall have the specified

tests carried out on representative samples of the material to be supplied. The tests shall be

carried out in a testing laboratory to be approved by the Superintendent. This testing shall be

carried out at the Contractor’s expense.

Where the Superintendent calls for additional tests not described in the Specification to be

carried out in order to check that the work complies with this Specification or the Drawings,

the cost of any tests whose results indicate non-compliance shall be borne entirely by the

Contractor.

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When the Superintendent has given approval for use of a particular material based on a

submitted sample or test result, no material shall be supplied which is inferior or varies in

grading from the sample supplied or tested, otherwise it may be rejected.

1.2.3 Regulatory Bodies

All work done under this Contract, all material used and all equipment, appliances and

machines installed shall conform in all respects with the requirements and regulations of

Government Departments or Statutory Authorities having control over or in any way regulating

the works. Municipal By-Laws, State Building, and/or Scaffolding Rules, Mines Department

Regulations shall be observed and the requirements fulfilled.

All work done shall meet the requirements of the responsible local authority, the Water

Corporation and Western Power who will inspect the work from time to time to ascertain

whether the standard of work meets their requirements.

1.2.4 Permits

All necessary permits required by any State or Local Government Authority shall be obtained

as part of the Contract and the fees paid by the Contractor.

1.3 As constructed information

The Contractor shall supply As Constructed information prior to the issue of the Payment

Certificate. As Constructed information shall be prepared and signed by a licensed surveyor

and be subject to endorsement by the Contractor’s Representative on each form and

Drawing to indicate compliance with the As Constructed requirements.

“As Constructed” Information shall be recorded prior to backfilling.

The Contractor shall provide the following ‘As Constructed’ information:

• WCX CAD Standard* Drawing files in AutoCAD or MicroStation format;

• wet signed original sheet size hard copy print of the above drawing files; and

• the original drawings marked-up (in red) hard copy print.

A set of original sheet size hard copy drawings and CAD files for ‘revision’ shall be provided

to the Contractor by the Superintendent.

*The WCX CAD Standard includes a WCX Manual and WCX CD and is available from Water

Corporation, Infrastructure Design Branch, 629 Newcastle Street, Leederville WA 6007 -

Phone (08) 9420 2294.

1.4 Public liaison standards

The Contractor shall ensure that persons employed in connection with the works conform to

the Water Corporation’s “Be Polite on Site” checklist. Offensive behaviour or language by any

person employed in connection with work under the Contract is not permitted. Breaches of

this requirement may result in the offender being removed from Site. The Contractor shall

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ensure that only designated and suitably attired employees, approved by the Superintendent,

are responsible for liaising with residents (including obtaining releases/approvals from

residents regarding restoration).

1.5 Site Facilities

1.5.1 Power & Water

The Contractor shall make arrangements and allow for electricity supply and water necessary

for carrying out the works of this Contract.

1.5.2 Medical Services

The Contractor shall provide, equip and maintain an adequate First Aid Treatment Centre on

the site and shall have an experienced First Aid person on site available at all times work is in

progress.

1.5.3 Location of Compound

The location of any compound used for the storage of plant or materials, and the positioning

of any site sheds, shall be subject to the approval of the Superintendent.

1.5.4 Site Office

Before commencement of the Work, the Contractor shall provide a site office which is in good

condition and is suitable for site meetings accommodating up to 8 persons. The Contractor

shall clean and maintain this office during the Contract. Air conditioning shall be provided if

daytime temperatures above 30°C are expected during the Contract.

1.5.5 Contractor’s Telephone Contact

Prior to commencement of work the Contractor shall provide a single telephone contact point

that shall be manned by the Contractor’s Representative 24 hours a day for the duration of

work on Site. This contact point is to enable members of the public and emergency services

to contact the Contractor’s Representative.

1.6 Public protection against vibration and damage

1.6.1 Pre-inspection of Buildings/Residences

a) Public and Private Properties

The Contractor shall undertake pre-inspections before the Works approach 100 metres

of the building/residence/in the following circumstances:

i) When construction vibrations or excavations are to occur within 5 metres of a

residence/building/masonry wall or;

ii) a resident/property owner shows concern or annoyance regarding construction vibrations

or;

iii) if any property owner/occupier or the Superintendent expresses concerns to the

Contractor regarding possible damage to a residence, then the Contractor shall carry out

a joint inspection of their property (including photographs) provided in a dilapidation report.

b) Heritage/Historical Buildings

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The Contractor shall identify any Heritage/Historic buildings in the Site by contacting the

National Trust of Australia (WA) and carry out such joint pre-inspections of such buildings

and at such times required by the Trust or the Superintendent.

c) Photographic Record/Dilapidation Report

The Contractor shall provide a photographic record (and video recording as necessary)

looking in both directions, of land and vegetation conditions and features including established

lawns, walls, roads, road verges, driveway crossovers fences, garden beds, paving, trees

and shrubs along the entire length of the proposed pipeline routes and at pumping station

locations for the purposes of subsequent restoration work quality assurance and insurance

claims assessment. A copy of the photographic record with each photograph duly

identified shall be supplied to the Superintendent at least 5 working days prior to the

commencement of construction work.

If the Contractor’s photographs are not of adequate quality to assess the pre-construction

condition of the Site, the Contractor may be liable for the cost of restoration as directed by the

Superintendent.

1.6.2 Vibration Monitoring

The Contractor shall ensure that the Peak Particle Velocity (PPV) caused by compaction

vibrations at the closest residence does not exceed 5 mm/s PPV.

When required, the Contractor shall, to carry out standard vibration monitoring to determine

the relevant PPV, engage a consultant who shall comply with AS 2187. If the Superintendent

elects to carry out an audit (in accordance with AS2187) of the vibrations caused to the

closest resident and the vibrations monitored are found to exceed 5mm/s PPV, then the

Contractor shall be liable for the cost of such audit.

1.7 Movement through private property

Movement through private property outside the extent of Works shall be prohibited

unless access through private property is essential. In such cases the Contractor shall obtain

permission from the owner of the affected property and shall limit all works to a maximum

period of two weeks.

1.8 Site meeting requirements

The Contractor, including any sub-contractors (if requested), shall attend Site meetings

convened by the Superintendent at fortnightly intervals or as may otherwise be directed.

The Superintendent will record minutes of these meetings.

1.9 Proprietary products or brands

Wherever a proprietary product or brand has been specified, an alternative equivalent

proprietary product or brand may be used if approved by the Superintendent.

1.10 Dewatering and disposal of dewatered products

Dewatering and effluent discharge shall be in accordance with the Dewatering Management

Plan and requirements of the DoW 5C Licence (client Supplied). T

he Contractor shall not discharge or cause to be discharged into any drain, lake, river or other

receiving waters any dewatered products which contain levels of salt, organic material,

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hydrocarbons, detergents or sediments which are incompatible with the receiving water

body.

Sewer trenches and excavations where the groundwater level is above the bottom of the

trench/excavation shall be dewatered to provide stable foundations for bedding materials.

Dewatering shall continue until the trenches/excavations have been backfilled to a sufficient

depth to prevent flotation of the pipes.

1.11 Safety

1.11.1 General

For the purposes of the Occupation Health Safety and Welfare Amendment Act 1987 and the

regulations thereunder the Contractor shall accept full responsibility for control of the

workplace and matters relating to the Act and shall be deemed to be the employer (as defined

under the Act) of all persons engaged by the Contractor and will accept full responsibility for

those persons on matters referred to in the Act.

The Contractor shall be fully informed of and meet the conditions contained in the Act and

Regulations.

The Contractor is required to ensure that all parties involved in the project demonstrate a

sound knowledge of standard safety measures. The Contractor shall be able to provide

relevant certification that all staff have received the appropriate level of training in the area of

safe practices. This applies to all persons who have access on the site, including sub-

contractors.

All vehicle entrances into the site shall be appropriately signed as being a Construction Site,

with access by approval only. The same signage shall also be erected at regular intervals

around the perimeter of the site, where pedestrian access might be possible.

Where the Superintendent considers that the Contractor is not meeting his obligations, he may

instruct the suspension of the works at the Contractor’s cost until such time as these

requirements are satisfactorily addressed.

The Contractor shall undertake the works in a safe manner and in accordance with:

• The Western Australia Occupational Safety and Health Regulations;

• Water Corporation's Contractor Health Safety and Environment Handbook.

1.11.2 Occupational Safety and Health Management Plan

The Contractor shall develop and submit a contract specific Safety and Health

Management Plan to the Superintendent for approval.

1.11.3 First Aid

The Contractor shall employ a site based person with St John’s Senior First Aid (or equivalent)

qualifications and shall provide, equip and maintain a St John’s Ambulance Association

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Industrial First Aid Kit, or similar, in an appropriate location at the Site. The Contractor

shall render first aid to any person associated with work under the Contract.

1.11.4 Excavations

The Contractor shall, prior to any excavation work:

• ensure that the size of the excavation of earthwork has been assessed by a competent

person to be self-supporting by virtue of the angle of the slope of the sides or the stability of

the matter comprising the sides.

The Contractor shall ensure Compliance with:

• OSH Regulations and Excavation and Earthworks;

• Excavation Code of Practice;

• each trench support or shoring system proposed for use has clear indelible markings,

including system weight, which uniquely identifies the system to a current certificate of

compliance with the Regulations;

• Water Corporation’s Contractor Health Safety And Environment Handbook; and

• each item of plant proposed for use as a crane has been indelibly marked with the

safe working load in compliance with the Regulations.

When fencing is dismantled temporarily to allow access by plant and workers, the excavation

shall be delineated by continuous visual barriers and cones/indicators/bollards at maximum

2 metre spacings on all sides.

At night or whenever an excavation is unsupervised, the Contractor shall, as a minimum,

either:

• Temporarily backfill the excavation;

• Erect a rigid fence a minimum of 1200mm high, i.e., chain wire supported within a

steel frame and covered with 900mm high visual barrier;

• Secure the excavation opening by appropriate flat steel covers;

• In trafficable areas - erect barriers in accordance with AS 1742.3, Clause 3.10.

Link to Water Corporation’s Contractor Health Safety and Environment Handbook in Water

Corporation web site:

http://www.watercorporation.com.au/-/media/files/suppliers/osh/contractor-health-safety-

environment-handbook.pdf

Appendix C

http://www.watercorporation.com.au/-/media/files/suppliers/osh/contractor-health-safety-environment-handbook.pdf

http://www.watercorporation.com.au/-/media/files/suppliers/osh/contractor-health-safety-environment-handbook.pdf


Shire of Dandaragan


1.11.5 Access Chambers Openings

The Contractor shall ensure that when access chambers/pumping stations are open

(other than when the ground level is more than 600mm below the top of the chamber) they

shall be made safe at all times either by:

• replacing the cover, or

• installing a temporary cover. i.e., steel mesh in a frame, or

• whenever the access chamber/pumping station remains open the Contractor shall comply

with the requirements of Prevention of Falls Standard S151.

1.11.6 Excavations and Microtunnelling Pits

For excavations and microtunnelling pits, the Contractor shall erect chain mesh security

fencing or rigid panel fencing, a minimum of 1800mm high (with suitable reflective

signs/parawebbing attached). The Contractor shall erect any additional measures to ensure

public safety is maintained at all times (including structural barriers in accordance with

AS1742.3).

1.11.7 Laser Safety Officer

A Laser Safety Officer shall be appointed to the Site by the Contractor. The Laser Safety

Officer shall comply with the requirements of AS2397.

1.11.8 Temporary Facilities/Resident’s Access

Whenever construction work impairs existing facilities or services, including the

property/swimming pool fencing, pet enclosures, laundry, toilet and driveway access of

an occupied property, equivalent temporary facilities shall be provided by the Contractor to

replace the impaired facilities.

Temporary pool fencing and pet enclosures shall be erected prior to the dismantling of

the existing facilities. The permanent facilities shall be restored as soon as practicable to a

standard at least equal to that which existed prior to the construction work.

The Contractor shall take photographs of the affected services and facilities and submit these

to the Superintendent with the photographic record prior to the commencement of

construction.

The property boundary fence and the driveway/pedestrian access to occupied properties

shall be restored to a functional, safe standard prior to the completion of work each day.

1.11.9 Employee’s Pets and Non-work Related Visitors

The Contractor shall not permit employee’s pets, children or other visitors on site, other than

those having business at the site.

1.11.10 Public Safety at Construction Sites – S152

Refer to Water Corporation's Contractor Health Safety and Environment Handbook.

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1.11.11 Personal Protective Equipment (PPE) – S22


1.11.12 Clearance to Work on Water Corporation Assets - WC-OSH -23


The contract documents or Superintendent will notify the Contractor if one or more

Clearance to Work Permits will be required to be obtained prior to commencing, or

during the course of the work.

The Procedure is used where either:

• The asset may need to be made safe for the Contractor to work on or adjacent, by

the Corporation.

• The work has the potential to interfere with the asset’s operation; or

• The work will substantially block access to the asset.

1.11.13 Quick-Hitch Assemblies

Where load-shifting mobile plant is fitted with a quick-hitch assembly, it shall be used with a

manually inserted locking pin or have an alternate means of protection.

1.11.14 Fall Prevention

Refer to the Water Corporation Prevention of Falls Standard S151.

1.11.15 Gas Testing and Confined Space Entry - WC-OSH-108.

Refer to WC – OSH - 108.

1.12 Flammable liquid installations

All elevated flammable liquid (hydrocarbon) installations within Underground Water Pollution

Control Areas shall be installed in accordance with the requirements of the Dept of

Environment.

1.13 Environmental protection

1.13.1 Dust Control

The Contractor shall carry out all operations in compliance with the current Dust Control

Guidelines as issued by the Environmental Protection Authority. This shall include the use

of watering carts, temporary windbreak fencing and hydromulching as necessitated by

the soil and wind conditions on Site. Water carts shall be available for up to 12 hours a

day including weekends and public holidays, at the Superintendent’s discretion.

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1.13.2 Noise Control

The Contractor shall prevent nuisance and unreasonable disturbance and ensure all work

under the Contract is undertaken in accordance with the Noise Abatement Act 1972

and the Noise Abatement (Annoyance of Residents) Regulations.

The Contractor shall arrange its operations and shall provide silencing equipment to its plant

to whatever extent is necessary to satisfy the requirements of the health regulations of

the relevant Local Authority in relation to the sound arising from the Contractor’s operations

near the boundaries of occupied properties.

The Contractor shall satisfy any reasonable instruction of the Local Authority health

inspector regarding noise levels within 1 day of having such instruction confirmed in

writing by the Superintendent.

1.13.3 Disposal of Rubbish, Cleared Vegetation, etc.

The Contractor shall keep the Site clean and tidy.

All rubbish, cleared vegetation and other debris resulting from the construction work

shall be disposed of off-site at intervals not exceeding 4 working days. Disposal shall

comply with the requirements of the Local Authority.

Burning may be carried out in compliance with the requirements of a valid current Local

Authority permit duly issued for the work, for each specific case. The permit shall be made

available for inspection by the Superintendent prior to any burning operation.

1.13.4 Removal of Unsuitable Material and Spoil (including ASS)

The Contractor shall remove and dispose of all unsuitable material and surplus spoil (including

ASS), other than material stockpiles approved for re-use, from properties and from road

surfaces at regular periodic intervals as necessary to avoid damage but not exceeding 4

working days.

Spoil/unsuitable material removal and road sweeping techniques shall be such as to minimise

offence to residents and road users. The disposal shall be carried out in accordance with the

requirements of the Local Authority.

1.13.5 Contamination of the Site

The Contractor shall make provision, including the use of bunds for the storage and handling

of fuels and/or contaminants so that spillage or contamination of soil is prevented.

Contaminated soil shall be removed from the Site to a site approved for the disposal of

the fuels and/or contaminants involved.

1.13.6 Flora Conservation

The Contractor shall comply with the requirements of the Wildlife Conservation Act 1950,

and shall exercise care during the course of the work under the Contract to avoid

unnecessary destruction of native flora. The location of sites of rare flora known to the

Principal will be notified to the Contractor by the Superintendent who will also advise

of the measures to be taken. Any further sites suspected of coming under this category

found during the course of the work under the Contract shall be brought to the attention

of the Superintendent by the Contractor.

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1.13.7 Aboriginal Heritage Sites

The Contractor shall comply with the requirements of the Aboriginal Heritage Act by

immediately reporting any potential Aboriginal sites identified during the course of

construction to the Superintendent and ceasing works in that area until clearance has

been obtained from the Department of Aboriginal Affairs.

1.14 Sand drift

The Contractor shall abide by recommendations published by the Dept of Environmental

Protection (DEP). Their current document (1996) is entitled "Land Development Sites and

Impacts on Air Quality - A guideline for the prevention of dust and smoke pollution from land

development sites in Western Australia". For the purpose of these guidelines, the Site

Classification identified on the Drawings shall apply, or in the absence of any reference, Site

Classification 4 shall apply.

Additional obligations to the Contractor include:

i. the installation and maintenance of wind fencing as shown on the Drawings, for the duration that the site remains undisturbed, or until a permanent barrier (eg. screen fencing) is erected;

ii. soil stockpiles shall not exceed 2m in height, and shall be flattened on top to allow watering carts to travel over the stockpiles;

iii. having sufficient watering cart(s) such that one cart is in operation at all times.

At least one water cart shall be left filled at the end of each working day, so that it is available

for immediate use if required.

All disturbed areas shall be stabilised immediately upon completion of works in that location.

The stabilisation treatment shall consist of a paper mulch medium applied evenly over the

designated areas at a rate of 1700kg/ha.

The Contractor shall attend to any complaints arising from failure to control such a problem,

and bear all costs for compensation and cleaning.

The Contractor shall on request, within 48 hours, remove from public roads and other land

outside the Site sand or dust wherever the Superintendent considers the sand or dust

originated from the site of the works.

1.15 Notice of commencement of sewer works and notice of entry

The Contractor shall give to all land owners and occupiers of properties to be affected

by the work under the Contract, prior separate written notice of:

a) Commencement of work under the Contract in the area; and

b) Proposed entry onto properties.

The Contractor’s contact personnel included in these notices shall be the Contractor’s

Representative actively involved on Site or otherwise as approved by the Superintendent.

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1.15.1 Notice of Commencement of Works

The Contractor shall as soon as possible after award of the Contract, issue a Notice

of Commencement letter to all owners/occupiers of properties affected during the first

4 weeks of the Works. Thereafter the Contractor shall, on a progressive basis, provide

all other owners/occupiers of properties affected by the Works with approximately 4 weeks

written notice of the impending commencement of work.

1.15.2 Notice of Entry

The Contractor shall provide all owners/occupiers with a separate written Notice of Entry letter

not less than 7 or more than 14 days prior to the date when entry into the property is required

for the purposes of undertaking the Works.

On the Notice of Entry letter, the Contractor shall request that owners/occupiers indicate any

special requirements, including those necessary to provide for persons currently in residence,

who may have physical disabilities or impairments.

Further, the Contractor shall return to obtain the “copy” of the Notice of Entry letter endorsed

by the owner/occupier and provide all owners/occupiers with between 2 and 4 days verbal

notice of entry onto their property.

The Contractor shall maintain a file of the copies of the Notice of Entry letters endorsed

or otherwise by the owner/occupier and a written list of the owners/occupiers who

require pre-construction consultation (including structural inspection as necessary) and/or

who have other specific requirements. The Contractor shall submit a current list of any

specific requirements by residents to the Superintendent at each site meeting.

Upon request by the Contractor, the Superintendent will supply a list of the owners and

occupiers to the Contractor.

1.15.3 Boundary fence relocation

Whenever a boundary fence is to be temporarily removed, and the Contractor’s setting-out

has identified that the position of the fence differs considerably in position to where it

should be located on the legally defined cadastral boundary then the Contractor shall, before

the removal of such fence:

a) inform the details of such difference in fence location to the Superintendent who will

serve notice on the owners of the affected properties, to the effect that the Water

Corporation will, unless written response is received from the owners within 3 weeks

from the date of service of the notice, instruct that the fence be replaced in the position it

was found prior to its removal.

The notice will indicate that if the owners require the fence to be positioned on the

cadastral boundary they will, at their own expense, commission a licensed surveyor to

establish the correct boundary and must forward a written advice to the Water Corporation.

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b) the Superintendent will direct the Contractor as to the outcome of the Notice to the

owners within 2 working days of the closing date for the owner to request correct re-

establishment of the fence.

The Contractor’s surveyor may liaise with the owner to obtain such formal request at an

earlier date at the Contractor’s discretion.

1.16 Planning requirements

1.16.1 General

The Contractor shall within 14 days of being awarded the Contract submit for approval

by the Superintendent (and the Local Authority) for:

• Location for storage/spoil sites/site compounds

At least 5 working days prior to the commencement of excavation on site, the Contractor shall:

(a) give notice of commencement of excavation to the Superintendent;

(b) carry out an initial condition inspection of the Local Authority’s

improvements/roadways; with the Local Authority and the Superintendent;

At this inspection the Contractor shall record the level of the deterioration of the Local

Authority’s improvements and agree such recording with the Superintendent;

(c) for those roads for which the kerbs and/or roadway crowns will be disturbed/removed;

complete an As Constructed survey of the existing sealed roads with cross-sections at

10m intervals and levels of low points along the extent of the roadways to be affected by the

sewer works;

(d) submit test results of bulk samples of proposed sub-base and basecourse materials and

agree the pavement structure;

(e) submit details for proposed spray sealing, including spray rates and aggregate

applications for bituminous seals;

(f) submit details of proposed mixes for asphaltic concrete;

(g) obtain the Local Authority’s standard stormwater drainage pit drawings, drainage pit

reconstruction requirements, kerb-type requirements and stormwater construction

specification. The Contractor shall conform with such standards.

1.17 Clearance to work (CTW) requirements

The assets for which a CTW Permit is required will be advised to the Contractor by the

Superintendent following the award of the Contract.

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2 SITE PREPARATION

2.1 Clearing and grubbing

2.1.1 General

Clearing and grubbing shall include the removal of all foreign material and vegetation including

trees, logs, stumps, rootings, scrub, bush, concrete, masonry boulders and rubbish (except

trees and plants required to be preserved), within the limits of the area in which clearing is to

be carried out. Care shall be taken to prevent damage to survey marks or pegs.

Grass shall be removed only at the time topsoil is stripped.

Clearing and grubbing shall be executed in advance of earthwork operations.

Clearing and grubbing shall be carried out over the entire area in which earthworks are to be

executed except where trees are required to be retained.

All roots over 75mm diameter and all stumps shall be grubbed out to a depth of 600mm below

the natural surface or 400mm below the finished surface level whichever is the lower, and

disposing of all spoils resulting from the clearing and grubbing.

All holes and depressions resulting from clearing and grubbing shall be inspected by the

Superintendent prior to being filled in with approved material, and compacted to the same

density as that of the surrounding undisturbed soil.

All material cleared in accordance with this Specification shall become the property of the

Contractor. Unless otherwise stated, it is the Contractor’s responsibility to determine what

method of disposal of the cleared material is allowed by the relevant local authority and DEP,

and to price accordingly. No variation for more costly methods of disposal will be entered into.

If burning is allowed by relevant local authority and DEP, burning shall be carried out only in

cleared areas remote from the buildings and vegetation, and then only with the approval of

the appropriate Fire Authority and in accordance with the Bushfire Acts.

2.1.2 Protection of Trees

Extreme care shall be taken to prevent damage to all trees that are not to be removed under

this Contract and particular care shall be taken to avoid damage to the roots, trunks and

branches. A suitably tensioned paraweb fence shall be erected around the drip-line of each

tree (or stand of trees), and maintained for the duration of the Contract.

Typically, all trees to be retained should be marked with a white band painted on the tree trunk.

2.2 Topsoil

Prior to commencement of work on earthworks, natural topsoil shall be stripped from areas to

be earthworked to a minimum depth of 100mm. Grass shall be stripped off together with the

topsoil. Care shall be taken to avoid contamination by any other material.

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The topsoil shall be stockpiled in positions approved by the Superintendent and, when

earthworks have been formed in accordance with the Drawings and Specification, the topsoil

shall be evenly graded over the exposed earth surface to not less than 75mm compacted

depth (but not more than 100mm compacted depth) to agree with the finished surface levels

requiring topsoil as shown on the Drawings.

If the site fails to yield sufficient topsoil for respreading over all disturbed areas, the Contractor

shall, at his expense, import the necessary quantity of topsoil to achieve the required

coverage.

Topsoiled areas, when finished, shall present smooth surfaces free of stones, timber, and

lumps of soil, blending into adjoining undisturbed ground.

2.3 Disposal of surplus soil

All surplus topsoil not required by the Contractor for the resoiling of nature strips, tree planting

purposed or for any other use in the works shall be completely removed from the site and

disposed of at an approved location external to the site of works.

All other surplus material or spoil excavated for the construction of the works in this Contract

shall also be completely removed from the site and disposed of at an approved location

external to the site of works.

No additional payment or compensation shall be allowed to the Contractor for this work in any

form whatsoever.

2.4 Rock excavation

When necessary for the purpose of payment, the different kinds of material met within

excavation shall be classified under the headings “Other than Rock” or “Rock Excavation” and

where such words occur in the Contract Documents they shall have the following meanings:

“Other than Rock” shall mean all kinds of materials, which in the opinion of the Superintendent do not require blasting or removal by jackhammer or mechanical rock breaker.

“Rock Excavation” for Bulk Earthworks shall be defined as:

o Any rock that can not be ripped using a Caterpillar D10 dozer or equivalent machine, or

o Hard rock, which in the opinion of the Superintendent requires blasting and is in fact blasted, or removed by jackhammer or mechanical rock breaker.

“Rock Excavation” for Trench Excavations shall be defined as:

o Any rock that can not be excavated using a 30 tonne excavator equipped with a rock bucket, or

o Hard rock, which in the opinion of the Superintendent requires blasting and is in fact blasted, or removed by jackhammer or mechanical rock breaker.

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It shall be the contractor’s responsibility to submit a methodology for rock excavation in various

depths to the Superintendent and obtain the Superintendent’s approval in writing prior to

commencement of rock excavation.

The classification of the material being excavated must be agreed with the Superintendent at

the time of excavation. It shall be the Contractor’s responsibility to seek such agreement, and

to demonstrate that excavation is in rock.

It shall also be the Contractor’s responsibility to seek the Superintendent’s agreement in

writing for the volumes of the various classes of material excavated at intervals no greater

than one week during the course of the excavation work.

2.4.1 Rock Blasting

In the event of blasting being the preferred method to facilitate rock excavation, the contractor

shall notify the Superintendent in writing of his intention to use explosive at least five working

days before commencing the use of explosive. It shall be the contractor’s responsibility to

obtain all of the necessary approvals in writing from the relevant servicing authorities. The

contractor shall be responsible for complying with the provisions of the Explosive Act as

deemed necessary.

The contractor shall de-mobilise all of the un-necessary machinery and equipment during the

rock blasting process so that the client is not liable for payment of machinery down time. The

client shall provide additional payment to the contractor for re-mobilisation of machinery and

equipment as deemed necessary.

It shall be the contractor’s responsibility to seek the Superintendent’s agreement in writing for

any variation to the contract a rising from rock blasting prior to incurring any additional costs.

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3 PAVEMENTS

3.1 General

All works shall be constructed in accordance with the Contract Drawings and Specification

and will be subject to inspection and approval.

The pavement shall be constructed to the widths, grades, crossfalls, depths and lengths

shown on the Drawings.

3.2 Material

3.2.1 Testing

Routine testing of materials, compaction, course thickness and shape is required at each

stage of the roadworks. No work shall be commenced on the next stage until the existing work

has been approved by the Superintendent.

3.2.1.1 Compaction Testing

Compaction testing (in accordance with AS 1289) showing that the in situ density of the

various materials equals or exceeds the specified density limits for these materials shall be

basis of proof of satisfactory compaction. The frequency of testing proving adequate

compaction shall be at the rate of not less than one test per 300m2 of compacted surface area

of subgrade, sub-base, base course and asphalt, with a minimum of two tests for any isolated

section. The Superintendent may specify where tests shall be taken.

All testing shall be performed by an independent NATA-registered testing authority. The cost

of testing and any retesting shall be borne by the Contractor and deemed to be included in the

Contract Sum.

3.2.1.2 Materials Composition Testing

Testing showing compliance with the various requirements for the composition of road

construction materials as stated in the Specification shall be the basis for acceptance of the

material.

The frequency of testing shall be at the rate of not less than one test per 2000m² of compacted

surface area of sub-base, base course, asphalt, and segmental paving.

All testing shall be performed by an independent NATA-registered testing authority. The cost

of testing and any retesting shall be borne by the Contractor and deemed to be included in the

Contract Sum.

3.3 Subgrade

When the earthworks for any section to be paved have been completed and trenches have

been backfilled, the formation for the pavement shall be boxed out and regraded in conformity

with the profiles, dimensions, camber and depth shown on the Drawings. The subgrade shall

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be watered and compacted as necessary to a density of not less than 95% modified maximum

dry density on all material within 600mm of the required subgrade level.

Before compaction, the level of the subgrade shall be sufficiently high to allow for compaction

and any final adjustment of levels required shall be by cutting only and not by placing of fill.

Once preparation of the subgrade has commenced, vehicles and equipment shall not be

permitted on the formation except as required to compact the subgrade. The subgrade shall

be trimmed to within +0mm,-20mm of the nominated design level and to within +100mm, -

0mm of the nominated design width.

Notwithstanding, the Contractor shall be responsible for correction of all soft areas of subgrade

where the Superintendent determines that the Contractor's unsuitable operations are the

cause.

No further stage of construction shall be commenced until the completed subgrade has been

inspected and approved by the Superintendent and the Local Authority.

During sub-grade preparation, the works shall be maintained in such condition that they are

thoroughly drained at all times.

3.3.1 Sub-base

The sub-base material shall be crushed limestone from an approved source and crushed to

comply with the grading given below and to a width as shown on the drawings to a tolerance

of +300mm-0mm. The crushed limestone shall be free of sand, capstone, roots and other

foreign material. The compacted thickness of limestone sub-base shall be as shown on the

Drawings.

In the absence of specific requirements from the Local Authority, the limestone shall comply

with the following requirements, when sampled and tested in accordance with AS 1141 and

AS 1289.

Percentage of wear by Los Angeles test - not more than 60%.

Calcium carbonate content - not less than 60% nor more than 80% by weight.

Grading of:

AS SIEVE % PASSING

75mm 100%

19mm 50-75%

2.36mm 30-50%

75 micron ≤15% (By Weight)

The proportion of the sample passing the 0.425 sieve shall not have a linear shrinkage of

greater than 1.0%.

No sub-base material shall be placed until the sub-grade has been approved by the

Superintendent.

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The sub-base material shall be placed so that the sub-grade is not disturbed and broken up.

The sub-base material shall not be spread upon a water logged sub-grade. If at any time the

sub-grade material becomes mixed with the sub-base, the Contractor at his own cost shall

remove the mixture and reshape with clean sub-base material.

The sub-base material shall be compacted by rolling and watering to a firm, even and

unyielding surface to the satisfaction of the Superintendent. The compaction shall be in

accordance with the Local Authority’s requirements, but shall be not less than 95% of the

modified maximum dry density determined by testing in accordance with AS 1289.

Where in the opinion of the Superintendent, damage to adjoining properties may result, the

use of vibrating rollers will not be permitted.

The surface shall be tested by template to ensure accuracy. The Superintendent may direct

that any irregularities greater than l0mm when tested with a straight edge three metres long

be eliminated by reworking in an approved manner. In the absence of specific requirements

from the Local Authority, a maximum tolerance of + 15mm will be permitted. The thickness of

the sub-base shall not vary by more than +12mm-zero of the nominated layer thickness.

3.4 Base course

The base course material shall be lateritic gravel fine crushed rock from an approved source

and to a width as shown on the drawings to a tolerance of +300mm-zero. The compacted

thickness of the base course shall be as shown in the Drawings.

In the absence of specific requirements from the Local Authority, the crushed rock shall comply with the following requirements when sampled and tested in accordance with AS 1141 and AS 1289.

Percentage of wear by Los Angeles test - not more than 45%.

Grading of:

AS SIEVE % PASSING

19mm 100%

9.5mm 70-80%

4.75mm 40-65%

2.36mm 30-50%

0.425mm 12-30%

0.075mm 3-12%

The ratio of the portion passing 0.075mm sieve to the portion passing 0.425mm sieve shall fall within the range of 40-60%.

The portion retained on the 0.425mm sieve shall conform to the following requirements.

Linear shrinkage not greater than 1 %

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Lower liquid limit not greater than 25

Plasticity index not greater than 5 nor less than 2.

Dry compressive strength not less than 1.75 MPa

Dust ratio shall not exceed 0.67

No base course shall be placed until the sub-base has been approved by the Superintendent.

The base course shall be maintained at optimum moisture content, within a tolerance of 2%

(two per cent) until spreading and compaction is completed, additional water being added as

necessary during rolling.

Materials shall be spread without segregation of large or fine particles. Segregated materials

shall be re-mixed by harrowing and blading or, if ordered by the Superintendent, they shall be

cast to waste.

The base course shall not be spread upon a waterlogged sub-base. If at any time the sub-

base material should become churned up or mixed with the pavement, the Contractor shall,

without additional compensation, remove the mixture and re-shape with clean material, which

shall be satisfactorily compacted uniformly with the surrounding surface.

The base course shall be compacted by rolling and watering to a firm, even and unyielding

surface, to the satisfaction of the Superintendent. The compaction shall be in accordance with

the Local Authority’s requirements, but shall be not less than 98% of the maximum dry density

determined by testing in accordance with AS 1289.

The surface shall be tested by template to ensure accuracy, and any irregularities greater than

10mm when tested with a straightedge 3m long shall be made good by addition or removal of

material and further rolling until the specified cross-section is obtained. In the absence of

specific requirements from the Local Authority, a tolerance of levels of + 5mm will be permitted.

The thickness of the base course shall not vary by more than +10mm-zero of the nominated

layer thickness after compaction.

3.5 Priming of Pavement

No surface shall be primed until the finished base course has been approved by the

Superintendent. A short time before the priming is to be commenced, the surface shall be

finished by light watering, planing and rolling with multi-wheeled, pneumatic-tyred rollers.

The mulch which forms on the surface shall be removed from the pavement by light grading

and brooming to provide a surface free from loose stones, dirt and foreign matter. At this

stage, the pavement shall be dry, or at most, only slightly damp and the surface pores free

from water down to a depth of 12mm.

In the absence of specific requirements from the Local Authority, the pavement shall be primed

with a medium curing cut back bitumen, consisting of 90% residual bitumen and 10% cutting

oils or ratios as determined by the Superintendent. The rate of application shall be not less

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than 1.20 litres/m² measured at 15ºC. The spraying temperature shall be between 70ºC and

120ºC.

Alternatively, a bitumen emulsion prime containing at least 60% by volume bitumen may be

used, subject to the Superintendent's approval. The rate of application shall be not less than

1.30 litres/m² measured at 15ºC. Emulsion primer may be heated to a maximum temperature

of 50ºC.

The method of application shall be in accordance with standard practice adopted by Main

Roads WA.

For cutback prime, sand or 1.5mm aggregate shall be applied after penetration of the primer

but while sufficient bitumen is on the surface to allow adhesion.

For emulsion prime, 5mm diorite aggregate shall be evenly applied at a rate of 100 square

metres coverage per cubic metre. The surface shall be rolled until the aggregate is firmly

embedded in the primer.

On no account shall the asphalt material be placed on a section of the primed base course

until such section has been inspected and approved by the Superintendent. A minimum of 72

hours after application of the primer shall elapse in all cases.

The primed spray shall be blinded after spraying.

3.6 Blinding

Blinding for the primer shall be 5mm or 7mm aggregate so that all sprayed areas shall be

completely covered by aggregate within a period of 15 minutes. Sealing aggregate shall be

applied by suitably equipped gritter trucks capable of spreading a uniform layer of aggregate,

reversing over aggregate already applied.

The rate of application shall be determined by design but shall not exceed 150m2 per cubic

metre of metal, controlled so that only sufficient is applied to give a uniform dense mat one

stone thick. Additional aggregate may be added by hand spreading to any bare or

insufficiently covered areas to produce the required uniform cover.

Within 5 minutes of the application of the aggregate, rolling shall commence using self-

propelled steel wheel and pneumatic tyred rollers and continue until the aggregate is well

embedded in the binder and a uniform surface obtained.

3.7 Wearing course

The wearing course shall be an asphalt consisting of coarse aggregate, fine aggregate and

mineral filler uniformly coated and mixed with a bituminous binder.

The nominal size of the asphalt shall be as shown on the drawings, otherwise it shall conform

to the following requirements.

Local Road - 7mm nominal size asphalt with a compacted thickness of 25mm;

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10m wide roads and arterial roads - 10mm nominal size asphalt with a compacted

thickness of 25mm.

Thicklift pavement – 10mm nominal size asphalt with a compacted thickness of 40mm.

The aggregate shall consist wholly of crushed diorite material produced from sound stone

having a Los Angeles Abrasion Test value of not greater than 30% or a mixture of crushed

material and natural sand provided that, if natural sand is included in the mixture, the amount

used shall be so limited that the mixture of aggregate passing the 4.75mm A.S. Sieve will

contain not less than 50% by weight of crushed particles. The flakiness index of the aggregate

shall not exceed 35%.

Filler, if required, shall consist of Portland Cement, ground limestone or stone dust.

The paving mixture for the surface coarse shall meet the following requirements by weight

when determined by A.S. sieves. The residual binder, that is the residual asphaltic bitumen,

shall be determined as a percentage by weight of the total mixture.

AS SEIVE % MINERAL AGGREGATE

Nominal Size

7mm

PASSING SIEVE SIZE

Nominal Size

10mm

28.5mm

19.0mm

13.2mm 100

9.50mm 100 90-100

6.70mm

4.75mm 68-88 54-74

2.36mm 49-67 39-57

1.18mm 37-53 29-45

600um 25-41 19-35

300um 15-27 11-23

150um 8-16 6-14

75um 4-8 3-7

TOTAL MINERAL MATTER 100% 100%

Nominal Width 7mm 10mm

Percentage of Bitumen to total

mix (by weight)

5.00-7.00 4.00-6.00

Marshall Stability Test

(minimum)

5.5kN 6.5kN

Marshall Flow Value (mm) 2-4 2-4

Range of air voids in total mix

when compacted

3-5 3-5

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Strict control of temperature shall be maintained to avoid burning of the binder and to also

provide maximum laying qualities in the mix.

The following limits shall apply.

Maximum aggregate temperature = 190ºC

Maximum bitumen temperature = 160ºC

Maximum temperature of mix leaving plant = 175ºC

Minimum temperature of mix at spreader = 135ºC

3.7.1 Tack Coat

A tack coat of rapid breaking cationic bituminous emulsion (CRS/50-60 Grade) shall be applied

to the primed surface at a rate between 0.20 and 0.50 litres per sq. metre.

The existing surface shall first be swept to the satisfaction of the Superintendent to a clean,

dry surface.

When ordered, splash guards shall be supplied and used to protect property, traffic and

adjoining work from damage. The Superintendent shall direct the length of tack coat which

may be put out beyond the point at which the spreading of asphalt is to be undertaken and the

period of time which must elapse before spreading commences on the tack coat. This time

shall normally be not less than 30 minutes not more than 2 hours.

3.7.2 Placing the Mixture

The mixture shall be laid upon a base which is dry and only when weather conditions are

suitable and atmospheric temperature above ten (10) degrees centigrade.

The mixture shall be spread to line and camber without tearing, gouging or shearing to produce

a surface free from waves.

The mixture shall be spread in such a manner as to minimise the number of joints in the

pavement. More than one longitudinal joint will not be permitted if the total width is 7.4m or

less.

Longitudinal and transverse joints shall be made in a careful manner well bonded and sealed.

Joints between old and new pavements or between successive days work, shall be carefully

made to ensure a thorough and continuous bond between the old and new surfaces.

Immediately after any course is spread and before roller compaction is started, the surface

shall be checked, any inequalities adjusted, all fat, sandy, segregated hungry or dusty

accumulation from the screed removed by a rake or hoe and replaced with satisfactory

material.

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3.7.3 Compaction of Mixture

After spreading, the mixture shall be thoroughly and uniformly compressed as soon after being

spread as it will bear the roller without undue displacement.

An approved brush or similar device shall be fitted so that each tyre or roll is kept clean of

foreign material and kept uniformly wet. Tyres shall be free of pit marks.

The Contractor shall provide a minimum of one steel three-wheeled roller and one pneumatic

tyred roller for each asphalt paver in use on the job, but the Superintendent may require the

provision of additional rolling equipment if, in his opinion, the rollers on the job are not obtaining

the required compaction of the mixture.

For compacting confined areas, the Contractor shall provide a small roller and/or a mechanical

impact type or vibrating type hand-operated compactor of size and mass acceptable to the

Superintendent.

Undue delays in rolling freshly spread mixture will not be tolerated. Initial compaction of the

asphalt shall be achieved using the self-propelled steel wheel roller. Rolling shall start

longitudinally at the sides and proceed toward the centre of the pavement overlapping on

successive passes by at least 150mm. Successive passes of the roller shall be of slightly

different lengths.

Where the width of the pavement permits, the pavement shall then be subjected to diagonal

rolling in two directions, the second diagonal rolling crossing the lines of the first.

The speed of the steel wheeled roller shall not exceed 5 km/hour, or 10 km/hour in the case

of a pneumatic tyred roller and shall be at all times slow enough to avoid displacement of the

hot mixture. Any displacement occurring as a result of reversing the direction of the roller, or

from any other cause, shall at once be corrected by the use of rakes and of fresh mixture

where required. Rolling shall proceed continuously until all roller marks are eliminated and no

further compression is possible.

Along kerbs, channels, headers, rnanholes and similar structures, and at all places not

accessible to the roller, thorough compaction shall be secured by means of hot tampers and

at all contacts of this character the joints between these structures and the mixture must be

effectively sealed.

After final compaction the course shall conform to the following requirements in the absence

of specific requirements from the Local Authority. It shall:

i. Be smooth and true to the established crown and grade, and be within a tolerance of + 5mm of the design level;

ii. At no point vary more than -0mm to +5mm from the specified thickness indicated on the Drawings;

iii. Have crown or crossfall as directed by the Superintendent;

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iv. When finished, at no point have a density of less than 97% of the Marshall Maximum density; and

v. Have a surface slope such that ponding of water cannot occur at any point.

Any low or defective places shall immediately be remedied by cutting the course at such spots

and replacing it with fresh hot mixture which shall be immediately compacted to conform with

the surrounding area and shall be thoroughly bonded to it. The surface of the finished course

shall be free from depressions exceeding 5mm as measured with a three metre straightedge.

3.7.4 Opening to traffic

The Superintendent may permit any portion of a course to be opened to traffic. No traffic shall

be permitted on any surface until it has cooled to atmospheric temperature.

3.8 Concrete kerbs

Concrete kerbs shall be constructed to the dimensions shown on the Drawings.

Kerbs shall be constructed in situ by an approved kerbing machine. They shall be placed in

straight lines and horizontal and vertical curves as shown on the Drawings, and to the levels

shown on the Drawings.

The concrete used shall have a minimum compressive strength of 25 MPa at twenty-eight

days. This strength shall be determined in each test by the average of two duplicate

specimens moulded from concrete actually being placed in the work, selected to represent

truly the whole of the concrete poured on the day of moulding. The concrete shall be

composed of a mixture of screenings, sand and cement to give the strength specified with a

maximum slump of 90mm. The maximum aggregate size is to be 10mm.

Ready mixed concrete shall conform to the requirements of AS 1379.

The Contractor shall provide all materials, labour and facilities for the manufacture of

cylindrical concrete test specimens, including the necessary moulds at such times during the

course of the Contract as may be required. The test specimens shall be made, cured and

tested in accordance with AS 1012. The whole cost of obtaining concrete samples shall be

borne by the Contractor.

Contraction joints shall be provided at 2.5m intervals and formed perpendicular to the kerb

length by either a joint tool capable of cutting 20mm deep or a 5mm wide cut 66% though.

Immediately after the contraction joints have been formed the extruded kerb shall be finished

by the application of a 2 part sand to 1 part cement mortar by means of a kerb shaped screed.

The finishing shall bridge over the contraction joints to form a continuous cover

Not less than 24 hours after the placement of the kerb, transverse expansion joints shall be

provided in vertical planes at right angles to the kerb lines and at intervals not exceeding 5m,

coinciding with formed construction joints, and at sides of drainage gullies. The joints shall be

made with a full 12mm thickness cut filled with an approved butyl mastic compound and foam

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or polyurethane backing as detailed in the Drawings. Alternative filling materials may be used

if specifically approved in writing by the Superintendent.

The first 150mm of extruded kerb shall be neatly cut away and removed.

Care shall be taken to joint the new kerb to existing kerbs with a smooth join. All curves and

arises shall be smooth and true. Uniformity of colour must be obtained.

Within two hours of surface finishing, all exposed faces of kerb shall be protected from

moisture loss for not less than ninety six hours after extrusion by covering with plastic sheeting

or spraying with an approved curing compound.

Placing of backfill to kerbing shall proceed only after the kerb has cured and jointing is

completed.

The final alignment, shape and dimensions of the extruded kerb shall be as detailed on the

Drawings and shall have a smooth finish. The top surface of the kerb shall be parallel to the

ruling grade of the pavement and shall be free from depressions exceeding 5mm when

measured from a 3m long straight edge. When compared to the Drawings, the kerb level shall

be within ±5mm, the line shall be within ±10mm and the cross section dimensions shall be

within ±5mm.

3.9 Survey Checks

The Contractor shall provide at his expense, levels of the finished surface at all high and low

points, TP’s and at 20m intervals. Levels shall be taken at centreline and both kerb lines and

shall be certified by a licensed surveyor. These levels are to be submitted to the

Superintendent (in electronic and hardcopy format specified by the Superintendent) prior to

the granting of Practical Completion.

3.10 Clean Up

At the completion of all paving works, the Contractor shall clean away all debris resulting from

his works.

Kerbs shall be left clean and true to line, lids shall be exposed and flush with the finish paving

levels, stormwater pits shall be free from all debris and their surface flush with the pavement

as detailed.

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4 TRENCHING

4.1 Excavation

The Contractor shall excavate pipe trenches to the lines, levels, grades and widths shown or

specified on the Drawings, and in the Specification. Where necessary the trench shall be

widened and/or deepened to facilitate the making of joints, casing pipes with concrete and/or

to accommodate timbering while still maintaining the clearances specified between the

timbering and the pipes.

The Contractor shall establish prior to commencing excavation whether or not other services

exist in the path of or parallel to excavation. In the event of existence of any such services

the Contractor shall take every care not to damage such services. Any damage caused shall

be made good at the entire cost of the Contractor.

Open cut excavation of trenches will be an acceptable alternative to timbered trenches,

provided there is conformance to the following requirements.

The widths of open cutting shall be the absolute minimum practical and necessary for construction procedures.

Backfilling over the whole width shall be carried out as provided in this Specification.

The trench width for the first one metre depth (or pipe diameter plus 300mm whichever greater) shall be confined to the specified widths.

Where indicated on the Drawing or ordered by the Superintendent, the trench shall be

timbered to protect adjacent works or trees. Damage to adjacent works, whether or not the

Superintendent has given directions in this regard, shall be repaired at the Contractor's

expense.

The Contractor shall maintain the works area in a suitable dry condition in order that each and

every part of the works may be constructed to a high standard and for the protection of the

works against damage due to water.

During the construction of the works the Contractor shall, at the cost of the Contractor, take

every precaution necessary and provide all plant, materials and labour required for the

effective diversion and removal of surface and sub-surface water from the works.

Trenches in which the bottom is likely to be adversely affected by rain or seepage shall have

the last 150mm of excavation removed as a separate operation immediately prior to the laying

of the pipes or placing of bedding material. Such measures shall be carried out by the

Contractor at his own expense.

If pipe trench is excavated deeper than required, the extra depths shall be filled with 1:3:6

cement concrete or other approved material compacted to a density exceeding the natural

surrounding ground.

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Spoil from excavation shall be kept at least one metre from the edge of excavation. The height

of stockpiled spoil shall not exceed 2m above the existing surface.

The Contractor shall take whatever measures necessary to prevent the spoils of excavation

from being carried away by water or wind from the site.

Excavation in rock or hard soil may be carried out by blasting only if approval in writing has

been obtained from the Superintendent, the Police Department and the Local Authority.

4.2 Pipe bedding

Unless special bedding or pipe supports are shown on the Drawings or specified elsewhere,

the bedding material shall be clean sand or crushed rock.

Clean sand from the excavation may be used in dry conditions. The bed shall be carefully

shaped to receive the pipes with grooves to receive the pipe sockets so that the barrel shall

be uniform bearing along its length.

In wet conditions, a granular material such as gravel or crushed stone shall be used. The

material shall be 12mm nominal size and shall be shaped to receive the pipe as for sand

bedding except that the bedding shall extend to at least one quarter height of outside diameter

of the pipe.

4.3 Backfilling

Initial backfilling shall be undertaken using selected fill, being defined as sand, gravel or other

approved granular materials free of:

all stones retained on a 25mm sieve;

vegetable matter; or

any building debris

Initial backfilling at the sides and for 150mm above the top of the pipe shall be hand tool placed

and compacted ensuring that no joints or pipes are disturbed or damage. Reference shall be

made to standard drawings.

The joints shall be left fully exposed for inspection during testing. No part of the works or any

length of pipes or fittings shall be covered up until they have been inspected and approved by

the Superintendent. The Contractor may still be required to uncover and repair at the expense

of the Contractor, during the period of maintenance, any unsatisfactory work.

The material excavated from the trench may, subject to the approval of the Superintendent,

be used for ordinary backfill, provided it is free of rocks and vegetable matter.

Backfilling for the remainder of the trench may be by mechanical means and shall consist of

the excavated materials, provided that the material does not contain boulders or vegetable

matter which will cause damage to the pipe or uneven settlement of the pipe trench.

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All backfilling shall be in 300mm layers and compacted to not less than 95% of the maximum

dry density obtained in modified maximum dry density compaction tests (AS 1289.E2.1) or to

a density at least equal to that of the surrounding undisturbed ground, whichever is the greater.

Former topsoils shall be used as the top layer of backfilling except in roads where the

pavement shall be restored to its former or better state.

Any deficiency found in backfill shall be made good by adding and compacting approved

backfill material at the entire cost of the Contractor.

After the trench has been filled in, the Contractor shall immediately restore the surfaces, other

than in roads and driveways, to equal or better than their pre-existing conditions.

In roads and driveways, the Contractor shall immediately effect an interim restoration to a safe

and reasonable condition for traffic. The Contractor shall make good any settlement,

deterioration etc., as they occur.

The permanent reinstatement of roads shall not be commenced until the Superintendent is

satisfied that sufficient trench settlement has taken place. The materials used in permanent

reinstatement of roads shall be identical to materials used in adjacent roadwork. The roads

shall be restored to pre-existing or improved standards ensuring a good match of restored and

existing surfaces.

The Contractor shall make good at the expense of the Contractor any subsidence or

consolidation that occurs in the backfill and any damage caused by the subsidence before the

end of the maintenance period.

4.4 Basis of measurement

For payment purposes, the ground has been classified as soil, soft rock or hard rock. No rock

shall be paid for unless the amount has been measured and agreed by the Superintendent.

For payment purposes, the trench width shall be prescribed minimum width applicable to the

size of the pipe.

Measurement of trench depths for the purpose of determining the appropriate scheduled rate

for payment for excavation and refilling shall be made only at access chambers, pits and

headwalls and the depth of the trench at intermediate points shall be allotted to the several

depth groups on the assumption that the ground surface slopes uniformly between successive

points of measurement.

Work shall include all excavation, bedding, backfilling and compaction testing. Payment will

be made only for completed work, i.e. after the trench has been tested, backfilled and

consolidated and surplus spoil removed.

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5 GRAVITY SEWERS

5.1 General

The gravity sewer works shall be constructed in accordance with the Drawings, this

Specification and the Water Corporation’s current specifications and standard drawings. In

the event of any contradiction, discrepancy or ambiguity between anything contained in the

Contract Drawings or this Specification, and the requirements of the Water Corporation, then

the requirements of the Water Corporation shall prevail.

This section covers the excavation, laying, testing and backfilling of the gravity sewer mains.

5.2 Excavation and backfilling

Excavation and backfilling shall comply generally with the provisions of the Section 5.

The width of the trench shall be kept to the minimum consistent with bed width requirements

and the need for adequate working space and timbering if necessary. The maximum width of

the trench shall be 0.85 metres for pipes up to 230mm diameter. Where timbering is used the

above values shall be increased by 0.2 metres.

Backfilling of trenches shall not be carried out until sewers have been tested, approved and

measured as specified. At no time shall more than 300 metres of any single trench be open

(ie. excavated but not properly backfilled).

The fact of any such work being backfilled does not relieve the Contractor in any way of his

responsibilities and he may be called upon to uncover and repair, at his own cost, any sewer

declared by the Superintendent as unsatisfactory at any time until the end of the maintenance

period. Any such repair work shall be subject to retesting at the Contractor's cost.

The Contractor shall allow for and arrange for Perth sand penetrometer testing of sand backfill

to be carried out at a minimum frequency of one test every 30 metres of trench with additional

tests at each access chamber plus 1 test every 10 metres along side property boundaries and

2 tests each road crossing. All testing shall be repeated for each 1.5 metres of backfill. The

testing shall be carried out by an independent NATA-registered laboratory, testing in random

locations. Test results shall be submitted to the Superintendent on a weekly basis.

The Superintendent may order further penetrometer tests by the testing authority at his

discretion and at the Principal's cost. However all failed tests shall be at the Contractor's cost

and payment for these tests shall be deducted from payments due to the Contractor.

5.3 Trenchless Techniques

The Contractor shall ensure that the equipment selected for Trenchless Techniques are

appropriate for the known ground conditions. Trenchless techniques for the installation of

sewers shall be employed where shown on the Drawings or as directed by the Superintendent.

The Contractor may also elect to use trenchless techniques in lieu of open excavation.

Additional Geotech investigation may be required to be undertaken to determine the ground

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conditions under the direction of the Superintendent. In all cases, the Contractor shall submit

a proposal at least 10 days before this work is due to commence, which demonstrates that

the proposed technique(s) are capable of achieving the specified sewer construction

tolerances, or alternatively, agreed modified tolerances at the discretion of the Superintendent.

For sewers installed within a casing, the Contractor shall:

• For steel casing with support saddles, pressure grout the annulus between the sewer

and the casing,

• For non-corrosive casings with PVC support saddles, grouting of the annulus is not required.

However, concrete plugs shall be installed at each end of the annulus.

• For PVC casings with steel support saddles, pressure grout the annulus as per steel casings.

5.4 Materials

All pipes and fittings used for the construction of sewers shall be sound and shall bear the

manufacturers stamps. The pipes shall be placed with sockets uphill in perfectly straight lines.

5.5 Bedding

The pipes placed on pile and keel footings or on concrete keel shall be supported on mortar

wedges.

The pipes not placed on pile and keel or concrete keel shall be supported on sand bedding or

12 mm nominal sized crushed rock. Sand bedding shall be free draining granular material

extending to 150 mm below the barrel and half way up the side of the pipe for the width of the

trench. The sand bedding shall be used over sand foundations either dry or completely

dewatered. The bedding shall be completely dewatered. The bedding shall be compacted

and shaped to receive the pipes. Grooves shall be made in bedding material for the socket

of each pipe so that the barrel shall have uniform bearing throughout its length and ample

room for making joints. The crushed rock bedding shall be placed as detailed for sand bedding

except that the bedding shall extend at least to one quarter height of outside diameter of the

pipe.

The crushed rock bedding shall be used over stable foundations other than sand, however no

extra cost will be allowed for the provision of this type of bedding.

5.6 Junctions

Y-junctions for property connections shall be placed at the rate of one per each lot as ordered

by the Superintendent or as shown on the Drawings.

5.7 Access chambers

Access chambers shall be constructed to the details shown on the Drawings. Access

chambers in road verges and in private property shall be finished 30mm to 50mm above

natural surface. Access chambers in the roadway shall be finished flush with the level and

slope of the road so that the top of the access chamber blends into the road surface. Gatic

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type covers shall be used on all access chambers in the roadway and wherever there is danger

of infiltration. Access chambers requiring Gatic type covers are marked on the Drawings. All

access chambers shall be watertight.

Access chambers shall be so positioned with respect to incoming and outgoing sewers that a

long sweep channel can be formed in the access chamber. Channel covers are not required

except in drop access chambers. The channels shall be smooth.

The minimum number of brick courses above the corbel in access chambers is four and the

maximum number of brick courses is six,

All brickwork shall be neat and of house construction quality. The mortar used shall be 2 to 1

sand cement mortar with no additions.

All access chambers and pits shall be constructed true to shape size and position. Tolerance

for size shall be +6mm -0mm tolerance for position shall be 100mm. Tolerance for surface

plane shall be + 5mm, when measured from a 3m straight edge. All brickwork shall be

constructed with uniform and even 10mm thick joints both horizontal and vertical.

The tolerance for the thickness of joints shall be 1.3mm notwithstanding that the variation in

the thickness between adjacent bricks and courses shall not exceed 2mm.

All access chambers shall be left clean and free from all mortar droppings, markings,

extraneous matter, rubbish etc.

All sewer access chambers shall be waterproof.

5.8 Location of property connections

The position of each single property connection as shown on the Drawings is

approximate only and in some cases may be varied so that the length of private plumbing is

minimised. Inspection Shaft (IS) and Inspection Opening (IO) line positions are fixed if they

are serving more than one property.

The Contractor shall employ a suitably qualified plumber/drainer to obtain from the

Superintendent any constraints on the positioning of those single house connections for

specific lots (eg. lot contours, prior agreements and IO lines etc) and shall then liaise with

those property owners not affected by the above constraints, to determine the location of

the connection to best suit their plumbing needs. The Contractor shall ensure that these

owners confirm their lot connection location in writing before commencing these works,

otherwise the Contractor shall be required to provide an additional connection (at the

Contractor’s expense), if the property owner is not satisfied with the location of the

house connection initially provided.

5.9 Concrete encasements

All parts of the sewer closer than 3 metres in any direction to any tree excepting banksias shall

be encased in concrete.

Sewers shall be concrete encased elsewhere as specified in the Drawings.

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5.10 Testing, tolerances and as-constructed

The Contractor shall keep an up to-date accurate record of the exact location of squares in

the main line and Y-junctions. The location shall be given in distances from the centre of the

relevant downstream access chamber.

Any sewer line laid at a grade flatter than permitted by the Authority shall be reconstructed to

the grade specified in the Drawings at the entire cost of the Contractor.

The completed sewers shall be at the specified alignment and grade and shall be clean and

free from mortar droppings and sediments of any kind.

The grade of sewer between any two access chambers and a access chamber and an I.0.

shall be straight. The straightness of grade shall be tested with mirrors immediately after

emptying of the sewer subsequent to leakage tests, and also after completion of backfilling.

Ovality testing shall also be carried out.

The Contractor shall supply all equipment, labour and materials necessary for testing of

sewers. Sewer pipe testing shall be carried out and test results recorded in accordance with

a test schedule which shall be subject to approval by the Superintendent prior to the testing

work. The Contractor shall notify the Superintendent in writing of each or any testing operation

at least 2 working days in advance of the operation.

Each sewer and property connection, other than concrete sewers, shall be tested for water

tightness in test operations at two separate stages of construction. The first test shall be made

after pipe laying and the trenches shall not be refilled until the test results have been accepted

by the Superintendent. The second test shall be made after refilling of sewer trenches. The

method of test shall be either a hydrostatic test or an air test as described in this sub-clause.

5.10.1 Hydrostatic Testing of Upvc Sewers and Property Connections

During any test operation, unplasticised PVC (uPVC) pipe sewers and property connections

shall be subjected to a head of water of at least 1 m above the ground level at the highest

point of the test section of sewer but not exceeding 5 m total head at the lowest point of the

test section of sewer. The duration of the test shall be 15 minutes. A successful test shall

mean the absence of water flow or absence of visible evidence of significant moisture

penetration at joints at the end of the test period. Otherwise a hydrostatic test shall be deemed

to have failed.

5.10.2 Air Testing of uPVC Sewers and Property Connections

Each unplasticised PVC (uPVC) pipe sewer and property connection shall be subjected to an

air pressure of 50 kilopascals for 3 minutes. The air supply shall then be shut off and the

pressure of the air in the test section of sewer shall not fall below 35 kilopascals in less than

one minute of air testing.

5.10.3 Hydrostatic Testing of Concrete Sewers

Each concrete sewer shall be hydrostatically tested after laying of the sewer pipe but prior to

sewer trench refilling operations. Unless otherwise approved or directed, an hydrostatic test

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of a concrete sewer shall be effected by temporary disablement of the sewer trench

dewatering system. The duration of this test shall be 72 hours

A successful test shall mean absence of water flows and absence of visible evidence of

moisture, within the sewer being tested, at the end of the test period. It shall also mean

absence of visible evidence of water penetration behind sewer and access chamber plastic

lining work. Otherwise a hydrostatic test shall be deemed to have failed.

5.10.4 Ovality Testing of Concrete Sewers

The contractor shall carry out ovality testing in accordance with the requirements of the Water

Corporation. The contractor shall supply, and pay the costs, of all necessary test equipment

and labour.

5.10.5 Sewer Test Failure

In the event that testing of a section of sewer including access chambers and property

connections has resulted in failure as defined in this Specification, the section of sewer shall

be reworked including sewer joint repairs, sewer pipe replacement and plastic lining repairs

or replacement until a re-test has been accepted by the Superintendent as being successful.

Re-testing of a sewer shall mean a repeat hydrostatic test as specified herein.

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6 CONCRETE & MORTAR WORK

6.1 Materials

6.1.1 Concrete

The concrete shall conform to AS 3600 and shall be a mixture of cement, fine aggregate,

coarse aggregate and water proportioned so that the amount of fine aggregate shall be the

minimum that combined with the cement will produce only sufficient mortar to fill the voids in

the coarse aggregate and leave a slight excess for finishing and that the 28 day cylinder

strength of the concrete shall equal or exceed 25 MPa if not detailed otherwise in the

Drawings. The cement content of any mix shall not be less than 270 Kg/m3. No additives

shall be used in the concrete, unless otherwise approved by the Superintendent. The slump

shall not exceed 70mm or be less than 30mm. The maximum size of aggregate shall be

20mm.

6.1.2 Cement

All cement used shall be Portland Cement in accordance with AS 1315 and obtained from an

approved manufacturer. Cement shall be delivered to the site fresh and in sealed bags and

there stored in a weatherproof shed until such time that it is to be used. Any bag showing sign

of deterioration or setting is to be rejected.

6.1.3 Aggregate

Fine aggregate shall be well graded, clean, sharp and free from clay and organic impurities in

accordance with AS 1141 and AS 2758.1.

Coarse aggregate shall be crushed granite or diorite clear and free from all impurities and dust

in accordance with AS 1141 and AS 2785.1.

6.1.4 Water

Potable water shall be used in the concrete mix. The water shall be clean and free of any

deleterious matter before use in the mix.

The quantity of water used in the concrete shall be kept to the minimum necessary to ensure

adequate workability of the concrete. Under no circumstances may the water/cement ratio

exceed 0.60.

6.1.5 Sand

Sand for mortar will be crushed stone or natural sand free from all deleterious substances and

have a uniform grading. Sand for bedding or backfilling shall be clean sand free from roots,

clay or any deleterious matter.

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6.1.6 Steel

6.1.6.1 Reinforcement

Steel reinforcing fabric and steel reinforcing bars for concrete shall comply with the

requirements of AS 1302, AS 1303 and AS 1304 and be free from loose rust or matter likely

to impair the bond with concrete.

Structural steel shall comply with the requirements of AS 1250.

Contractor shall use reinforcement of the following types and grades:

High strength deformed bars, grade 500N (designated N on the drawings).

Obtain manufacturer’s guarantees or test certificates demonstrating compliance of

reinforcement with the relevant Australian Standard, if required.

6.1.6.2 Fixing

Support all reinforcement on plastic chairs or by other approved means. Tie reinforcement

with 1.25 mm diameter annealed steel wire ties.

All marking tags shall be removed.

All bars at splices shall be overlapped for a minimum of (unless otherwise shown):

Twisted deformed bars 40 mm

Round bar 50 mm

Fabric 200 mm

6.2 Mixing and placing

Concrete shall be mixed in an approved mechanical batch mixer. The aggregate and cement

shall be first mixed dry, then after the addition of water (the quantity of which shall be carefully

measured to ensure uniformity consistency of batches), the contents shall be mixed until there

is uniformity in colour and consistency, but in no case shall the mixing continue for less than

two minutes after the addition of water.

The concrete may be mixed in an approved central plant and transported on to the site in a

pre-mixed condition in specially constructed conveyances, or centrally batched and mixed in

transit by specially constructed transit mixers. Production and delivery of the concrete shall

be in accordance with the requirements of AS 1379.

A plastic surface of concrete shall be maintained until the completion of placing of that part of

the work.

Each batch of concrete shall be placed and compacted within 30 minutes of the concrete being

discharged from the mixer, or delivered to the site in a transit mixer and discharged there from.

The methods of handling and placing shall prevent segregation and/or loss of ingredients and

shall avoid re-handling. The concrete shall not be dropped by more than 1 metre. Open

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troughs and chutes where used shall be made of metal or lined with metal. Barrows and

buckets shall be of metal. The concrete shall NOT be thrown from shovels.

During and immediately after placing, the concrete shall be thoroughly compacted by

mechanical vibration or if necessary by hand in positions agreed by the Superintendent or the

Superintendent's Representative, around the reinforcement and shall be properly spaded

against the forms to ensure a good surface free from honeycombing. The concrete shall not

be subjected to any disturbance after being worked into place. Concreting shall be carried on

continuously between joints. The position of all construction joints shall be subject to prior

approval of the Superintendent. Newly placed concrete shall be adequately shielded from

harmful effects of sun, rain and frost.

6.3 Curing

All concrete shall be kept continuously damp for at least 7 days or until thoroughly cured. In

hot, dry or windy conditions, the exposed concrete shall be covered and sealed with a P.V.C.

membrane. or similar approved material, such that adequate moisture is retained for proper

curing.

6.4 Finish

All exposed surfaces of concrete shall be finished smooth and dense. All honeycombed

portions shall be cut out and made good to the satisfaction of the Superintendent immediately

after the formwork has been struck. All projecting imperfections shall be rubbed down flush

with carborundum stone or other approved means and resulting grit and dust thoroughly

washed off with clean water. Then as a separate operation a 1: 1 approved sand and Portland

Cement mixture shall be worked into the pores over the whole surface with a fine carborundum

float in such a manner that no material is left on the concrete face than is necessary to fill the

pores completely, so that a uniformly smooth and dense surface is presented.

6.5 Formwork

The design and construction of the forms shall be the responsibility of the Contractor. The

forms shall be removable without injury to the concrete. The forms shall be made either of

approved timber, free from loose knots and other defects, or metal in which all bolt and rivet

heads are countersunk in faces in contact with the concrete, or other approved material.

The forms shall be built true to line, and braced in a substantial and unyielding manner to

maintain position and shape. Joints in forms shall be either horizontal or vertical and the forms

and joints shall be mortar tight. Re-entrant angles shall be chamfered and corners filleted, the

bevel in each case having equal angles and sides of 25mm, if not shown otherwise in the

Drawings.

The contact face of timber formwork used for exposed concrete surfaces shall be made of

either dressed timber or undressed timber lined with an approved waterproof lining not liable

to warp, so that exposed concrete surfaces on stripping shall be smooth and even and true to

the dimensions and slopes given in the Drawings.

Forms shall be provided for all vertical surfaces of concrete to be placed in earth excavation.

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Dimensions affecting the construction of other parts of the work shall be checked carefully,

after the erection of forms and before the placing of concrete. The oil, grease or soap used

on forms to prevent adhesion of mortar shall be such that no discoloration of the surface of

concrete will result. The oil, grease or soap shall be spread uniformly in a thin film and any

surplus shall be removed prior to the placing of concrete.

No concrete shall be placed until the forms have been approved by the Superintendent. The

approval of the Superintendent does not relieve the Contractor from his responsibility to

provide adequate and dimensionally correct formwork at the required location, level and

alignment. If, after the concrete has been placed, the forms show any signs of bulging or

sagging, the affected part of the concrete shall be removed. The forms shall be reconstructed

rigidly to the satisfaction of the Superintendent and the removed part of the work shall be

reconstructed to the requirements of this Specification at the earliest opportunity. All this work

shall be completed at no cost to the Principal.

6.6 Reinforcement

The reinforcement shall be built up exactly as shown on the detail drawings and supported in

position so as to give the correct cover. Bars and stirrups shall be wired firmly together at all

points of intersections and the ends of all wires turned inwards away from the shuttering.

Fabric must be waved up over supports exactly as shown on the Drawings. The use of a

fabric bender is recommended.

The reinforcement shall be accurately bent cold to the shapes shown on the working Drawings

and all bends shall conform to the special details supplied.

The Contractor shall provide at the Contractor’s own expense all supports of timber or other

material, precast motor spacing blocks, tying wire and other materials.' Fabric reinforcement

shall be supplied in flat sheets. Any fabric which has been taken from a roll will not be allowed

to be used on the works.

6.7 Testing

The consistency of concrete shall be determined by the slump test in accordance with AS

1012.3. The Contractor shall provide the necessary equipment and conduct the test whenever

requested by the Superintendent.

The method of sampling fresh concrete for testing to be carried out in accordance with AS

1012.1.

The Contractor shall provide four standard moulds for the making of strength test cylinders in

accordance with methods prescribed in AS 1012.8. Cylinders shall be made when required

by the Superintendent and shall be tested after curing and maturing in accordance with AS

1012.9, AS 1012.10 and AS 1012.11, as appropriate.

The testing shall be at the expense of the Contractor.

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6.8 Mortar

Unless otherwise stated, mortar used throughout the work shall consist of a mixture of clean

sand and Portland Cement as specified. The proportions of sand and cement shall be

measured in approved gauge boxes. Particular care shall be taken to ensure uniformity of

colour and appearance of mortar where used for brickwork or rendering or other facing work.

When mortar is used in large quantities, a mixer of an approved type shall be used. In hand

mixing, material shall be thoroughly mixed on a boarded platform. Mortar shall be mixed only

for immediate use and any mortar that has once set or partly set or in any way deteriorated,

shall not be used.

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7 QUALITY ASSURANCE

7.1 General

The Contractor shall be responsible for achieving the specified standards and demonstrating

such achievement through testing and measurement and the provision of documentation which

covers all work under the Contract, both on site and offsite including the activities of all

Subcontractors and Suppliers.

A conformance record using the Quality Assurance Certificates QA-2 and relevant NATA test results

shall be maintained on a daily basis and made available to the Superintendent on demand. The

relevant completed QA-2 certificates shall be submitted to the Superintendent on a 2 weekly

basis and the satisfactory submission of all QA certificates by the Contractor shall be a pre-requisite

for the Works being accepted for payment.

The Contractor’s test results from penetrometer testing by site personnel and NATA registered

compliance penetrometer test results shall be submitted in accordance with the QA-2 Certificate.

7.2 Traceability

Traceability shall commence at the specified or nominated source point and finish at the location

where the material is incorporated into the Works. Traceability shall apply to (but not be limited

to):

a) Structural Concrete commencing at the batching plant;

b) Precast Access chamber Segments, fittings, ladders and access chamber covers;

c) Sewer Pipe and Fittings;

d) Sub-base Material;

e) Base Course Material;

f) Bitumen;

g) Asphalt.

7.3 Inspection

The Superintendent shall be provided access to any facility where work associated with the

Contract is being performed, including the facilities of Subcontractors or Suppliers and any

laboratory used for testing.

7.4 Conformance testing

7.4.1 Testing Personnel

All Contractor’s NATA registered compliance testing shall be carried out by a laboratory with

current National Association of Testing Authorities (NATA) registration for all test methods. NATA

registration for all test methods shall be maintained until completion of the Contract. All test

reports shall be NATA endorsed by a current NATA signatory. Survey to verify conformance shall

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be conducted by personnel with a minimum qualification for acceptance to the institution of

Engineering and Mining Surveyors, Australia or equivalent except where Licensed Surveyors

are specified.

7.4.2 Submission of QA Certificates/Test Results

The QA certificates shall be submitted to the Superintendent as follows:

a) Certificate QA-1: Project Preliminaries, the certificate shall be submitted once to cover the

contract and prior to the Contractor commencing any Works on Site.

b) Certificate QA-2: Sand Backfill Compaction (Penetrometer), a certificate for testing by the

Contractor’s site personnel shall be submitted for each length of sewer between two consecutive

access chambers/structures. The QA-2 certificate shall also be used for the Contractor’s NATA

testing.

c) Certificate QA-3: Acceptance of Works, the certificate shall be submitted once for each separable

portion of the Works and prior to its acceptance for Practical Completion.

♦ NATA registered test results for Road Construction shall be submitted on the NATA Testing

Authority’s own forms.

♦ Nuclear Densometer Test Results for Backfill with Other than Sand, shall be submitted on the

NATA Testing Authority’s own forms.

7.4.3 Sampling and Test Frequency

Sampling methods shall be unbiased and either random or systematic in concept or as specified.

For testing of road pavement particular regard shall be required for compaction around and over

structures such as culverts, access chambers and gullies. The frequency of tests shall at all

times be adequate to demonstrate the work’s conformance with the Specification.

7.4.4 Records and Reporting

The Contractor shall submit completed As Constructed and Quality Assurance Certificates to

the Superintendent at each 2 weekly site meeting. Manufacturer’s and supplier’s certificates shall be

submitted on request by the Superintendent and enable a clear trace of items from source to the

location within the Works.

Appendix C

Civil Technical Specifications - Shire of Dandaragan · Civil Technical Specifications Sewer Infill...

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