General Specification for Civil Engineering Works (GS), 2006 Edition Volume 1 of 2 (This Version is Continuously Updated to include Amendments issued) This Electronic File has incorporated the following Amendments:- RevIssue DateAmendment Incorporated First IssueMarch 2007- 19 J uly 2007Amendment No. 1/2007 227 December 2007Amendment No. 2/2007 317 J anuary 2008Amendment No. 1/2008 412 J une 2008Amendment No. 2/2008 56 February 2009Amendment No. 1/2009 626 August 2009Amendment No. 3/2009 726 November 2009Amendment No. 4/2009 82 February 2010Amendment No. 1/2010 99 March 2010Amendment No. 2/2010 1015 April 2010Amendment No. 3/2010 1119 April 2010Amendment No. 4/2010 129 March 2010Amendment No. 1/2011 133 August 2011Amendment No. 2/2011 145 April 2012Amendment No. 1/2012 157 February 2013Amendment No. 1/2013 1614 J une 2013Amendment No. 2/2013 1724 November 2014Amendment No. 1/2014 Thiselectronicfileisforreferenceonly.Whenthe contentofthiselectronicfileisinconsistentwiththe hard copy of the GS, 2006 Edition and the Amendments issued, the hard copy of the GS, 2006 Edition and the Amendments shall prevail. 2006 Edition The Government of the Hong Kong Special Administrative Region GENERAL SPECIFICATION CIVIL ENGINEERING VOLUME 1 GS (2006 Edition) 2 The Government of the Hong Kong Special Administrative Region The publication General Specification for Civil Engineering Works, 2006 Edition is available from : Publications Sales Unit Information Services Department Room 626, 6/F, North Point Government Offices 333 J ava Road, North Point Hong Kong and can be ordered both locally and overseas through the following channels: Visit the online Government Bookstore at www.bookstore.gov.hk Download the order form from the Information Services Department website at www.isd.gov.hk and submit the order direct online or by fax to the Information Services Department at 2523 7195 By e-mail at puborder@isd.gov.hk GS (2006 Edition) 3 FOREWORD The General Specification for Civil Engineering Works lays down the quality of materials, the standards of workmanship, the testing methods and the acceptance criteria for civil engineering works undertaken for the Government of the Hong Kong Special Administrative Region.Where necessary, this General Specification should be supplemented by a particular specification. The2006EditionoftheGeneralSpecificationcomprisesconsiderablegreeningofthe Eighth Reprint of the 1992 Edition (October 2002) according to the current green practices of the constructionindustry.Thetextrelatingto"greenmeasures"isprintedingreencolourinthis Edition with a view to making it easier for reader's reference.It was produced over a 15-month period from March 2005 under the guidance of a Steering Committee comprising members from the main Government departments involved in civil engineering works.The greening of each section was undertaken by a works department with the appropriate expertise.The Standards Unit of Civil Engineering and Development Department (CEDD) was responsible for the overall co-ordination of comments received from departmental circulation, editing and production of the document. Amd 1/2007 Sustainabilityistheprimeobjectiveofthe2006Edition.Twonewsections,viz. Environmental Protection (Section 25) and Preservation and Protection of Trees (Section 26) have been created.The original Section 22 for Railways Works has been deleted, as construction of railways is no more the responsibility of works departments.The 2006 Edition comprises 26 sections and is posted on the CEDD Homepage on the Internet. TheGeneralSpecificationwillbeupdatedcontinuously.Theelectronicfilesofthe sections affected by any amendment issued will be kept up-to-date on the CEDD Homepage. September 2006 GS (2006 Edition) 4 GENERAL SPECIFICATION FOR CIVIL ENGINEERING WORKS CONTENTS VOLUME 1 SECTION1 GENERAL 2SITE CLEARANCE 3LANDSCAPE SOFTWORKS AND ESTABLISHMENT WORKS 4FENCING 5 DRAINAGE WORKS 6EARTHWORKS 7GEOTECHNICAL WORKS 8PILING WORKS 9 CARRIAGEWAYS: SUB-BASE MATERIAL AND BITUMINOUS MATERIALS 10CONCRETE CARRIAGEWAYS 11MISCELLANEOUS ROADWORKS 12TRAFFIC SIGNS, ROAD MARKINGS AND ROAD STUDS VOLUME 2 SECTION13 WORK FOR ELECTRICAL AND MECHANICAL INSTALLATIONS 14FORMWORK AND FINISHES TO CONCRETE 15STEEL REINFORCEMENT 16CONCRETE AND JOINTS IN CONCRETE 17PRESTRESSING 18STEELWORK 19HANDRAILING, LADDERS, STAIRS AND FLOORING 20BRIDGEWORKS 21MARINE WORKS 22WATER SUPPLY PIPEWORKS 23WATER RETAINING STRUCTURES 24BUILDING WORKS 25ENVIRONMENTAL PROTECTION 26PRESERVATION AND PROTECTION OF TREES GS (2006 Edition) PageNo. 5 CONTENT OF VOLUME 1 SECTION 1 GENERAL INTERPRETATION OF DOCUMENTS 1.01Application of the General Specification for Civil Engineering Works ....................................... 1.3 1.02Abbreviations ................................................................................................................................ 1.3 1.03Glossary of terms .......................................................................................................................... 1.5 1.04Trials and approval ....................................................................................................................... 1.5 1.05British Standards, European Standards adopted as British Standards, Codes of Practice and other standards ....................................................................................................................... 1.6 1.06Specifications in metric and imperial units................................................................................... 1.6 1.07Dimensions from Drawings .......................................................................................................... 1.6 PROGRAMME 1.08Programme.................................................................................................................................... 1.6 CONTRACTOR'S SUPERINTENDENCE 1.09Surveyor........................................................................................................................................ 1.7 1.10Foreman for concrete works ......................................................................................................... 1.7 1.11Supervision of piling works .......................................................................................................... 1.7 1.12Particulars of Agent and employees ............................................................................................. 1.8 CONSTRUCTION SAFETY AND SAFETY OF THE PUBLIC 1.13Construction safety and safety of the public ................................................................................. 1.9 WORK ON ROADS 1.14Approval for temporary traffic arrangements and control .......................................................... 1.10 1.15Temporary traffic arrangements and control............................................................................... 1.10 1.16Particulars of temporary traffic arrangements and control ......................................................... 1.11 1.17Use of roads and footways .......................................................................................................... 1.11 1.18Work on roads and footways ...................................................................................................... 1.11 1.19Reinstatement of roads and footways ......................................................................................... 1.12 CARE OF THE WORKS 1.20Protection from water ................................................................................................................. 1.12 1.21Protection from weather ............................................................................................................. 1.12 1.22Protection of works ..................................................................................................................... 1.13 DAMAGE AND INTERFERENCE 1.23Damage and interference ............................................................................................................ 1.13 1.24Watercourses and drainage systems ............................................................................................ 1.13 1.25Utilities ....................................................................................................................................... 1.14 GS (2006 Edition) PageNo. 6 1.26Structures, roads and other property ........................................................................................... 1.16 1.27Access ......................................................................................................................................... 1.16 RECORDS 1.28Records of wage rates ................................................................................................................. 1.16 1.29Records of correspondence ......................................................................................................... 1.16 1.30Records and reports .................................................................................................................... 1.16 LIAISON WITH OTHERS 1.31Liaison with others ..................................................................................................................... 1.17 SITE CLEANLINESS 1.32Site cleanliness ........................................................................................................................... 1.17 1.33Prevention of mosquito breeding ................................................................................................ 1.18 1.34Prevention of dust ....................................................................................................................... 1.18 MATERIALS AND EQUIPMENT 1.35Materials and equipment provided by the Employer .................................................................. 1.19 1.36Materials ..................................................................................................................................... 1.19 TESTING 1.37Quality assurance schemes ......................................................................................................... 1.19 1.38Batches, samples and specimens ................................................................................................ 1.20 1.39Samples for testing ..................................................................................................................... 1.20 1.40Testing ........................................................................................................................................ 1.22 1.41Compliance of a batch ................................................................................................................ 1.23 1.42Raw records of tests and test reports .......................................................................................... 1.23 WORKMANSHIP AND TOLERANCES 1.43Workmanship .............................................................................................................................. 1.24 1.44Tolerances ................................................................................................................................... 1.24 SITE ESTABLISHMENT 1.45Use of the Site ............................................................................................................................. 1.24 1.46Submission of particulars ........................................................................................................... 1.24 1.47Survey of the Site ....................................................................................................................... 1.25 1.48Fences and signs on the Site ....................................................................................................... 1.25 1.49The Engineer's Site accommodation ........................................................................................... 1.25 1.50The Contractor's Site accommodation ........................................................................................ 1.26 1.51Site utilities and access ............................................................................................................... 1.26 1.52Transport for the Engineer .......................................................................................................... 1.26 1.53Clearance of the Site ................................................................................................................... 1.27 MEETINGS 1.54Meetings ..................................................................................................................................... 1.27 GS (2006 Edition) PageNo. 7 PHOTOGRAPHS 1.55Photographs ................................................................................................................................ 1.28 APPENDIX 1.1 STANDARDS 1.1.1BRITISH STANDARDS ............................................................................................................ 1.29 1.1.2AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) STANDARDS ........... 1.43 1.1.3AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS (AASHTO) STANDARD ...................................................................................... 1.45 1.1.4AMERICAN WATER WORKS ASSOCIATION (AWWA) STANDARDS/ AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) ..................................................................... 1.45 1.1.5CONSTRUCTION STANDARDS OF THE GOVERNMENT OF THE HKSAR .................... 1.45 1.1.6SWEDISH STANDARDS .......................................................................................................... 1.45 1.1.7AMERICAN PUBLIC HEALTH ASSOCIATION (APHA) STANDARDS ............................. 1.45 1.1.8EUROPEAN STANDARDS ADOPTED AS BRITISH STANDARDS (BS EN) ..................... 1.45 1.1.9EUROPEAN STANDARDS (EN) and/or INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO) STANDARDS ADOPTED AS BRITISH STANDARDS (BS EN ISO) ............................................................................................................................... 1.50 1.1.10J APANESE INDUSTRIAL STANDARDS (J IS) ....................................................................... 1.52 1.1.11INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO) STANDARDS............................................................................................................................. 1.52 1.1.12WATER INDUSTRY SPECIFICATION, WATER RESEARCH CENTRE ............................... 1.53 1.1.13NATIONAL WATER COUNCIL, UK ....................................................................................... 1.53 1.1.14AUSTRALIAN/NEW ZEALAND STANDARDS (AS/NZS) ................................................... 1.53 1.1.15 ........................................................................................................ 1.53 1.1.16CANADIAN STANDARD ........................................................................................................ 1.53 APPENDIX 1.2 REQUIREMENTS FOR STEEL CONTAINER ROOM 1.2.1General........................................................................................................................................ 1.54 1.2.2Equipment ................................................................................................................................... 1.54 APPENDIX 1.3 REQUIREMENTS FOR CURING TANK 1.3.1General........................................................................................................................................ 1.55 1.3.2Equipment ................................................................................................................................... 1.55 1.3.3Maintenance ................................................................................................................................ 1.55 SECTION 2 SITE CLEARANCE GENERAL 2.01General requirements .................................................................................................................... 2.3 2.02Pipes and manholes to be abandoned ........................................................................................... 2.3 2.03Earthworks .................................................................................................................................... 2.3 GS (2006 Edition) PageNo. 8 SITE CLEARANCE 2.04Demolition .................................................................................................................................... 2.3 2.05Pipes and cables ............................................................................................................................ 2.3 2.06Trees ............................................................................................................................................. 2.3 2.07Reinstatement ............................................................................................................................... 2.3 2.08Materials and equipment for re-use and storage ........................................................................... 2.4 SECTION 3 LANDSCAPE SOFTWORKS AND ESTABLISHMENT WORKS GENERAL 3.01General requirements .................................................................................................................... 3.3 3.02Site clearance ................................................................................................................................ 3.3 3.03Earthworks .................................................................................................................................... 3.3 3.04Landscape hardworks ................................................................................................................... 3.3 3.05Geotechnical works ...................................................................................................................... 3.3 3.06Weather and ground conditions .................................................................................................... 3.3 3.07Use of chemicals ........................................................................................................................... 3.3 GLOSSARY OF TERMS 3.08Landscape softworks .................................................................................................................... 3.3 3.09Landscape hardworks ................................................................................................................... 3.3 3.10Establishment works ..................................................................................................................... 3.3 MATERIALS 3.11Seedling trees ................................................................................................................................ 3.4 3.12Whip trees ..................................................................................................................................... 3.4 3.13Light standard trees ...................................................................................................................... 3.4 3.14Standard trees................................................................................................................................ 3.5 3.15Heavy standard trees ..................................................................................................................... 3.5 3.16Semi-mature trees ......................................................................................................................... 3.5 3.17Small shrubs ................................................................................................................................. 3.6 3.18Large shrubs.................................................................................................................................. 3.6 3.19Conifers ........................................................................................................................................ 3.6 3.20Palms ............................................................................................................................................ 3.7 3.21Bamboos ....................................................................................................................................... 3.7 3.22Herbaceous plants ......................................................................................................................... 3.7 3.23Ground covers ............................................................................................................................... 3.8 3.24Climbers........................................................................................................................................ 3.8 3.25Containerised plants ..................................................................................................................... 3.8 3.26Grass seed ..................................................................................................................................... 3.8 3.27Turf ............................................................................................................................................... 3.9 3.28Sprigs ............................................................................................................................................ 3.9 3.29Plant name .................................................................................................................................... 3.9 3.30Soil-mix ........................................................................................................................................ 3.9 3.31Soil conditioner ........................................................................................................................... 3.10 3.32Mulch .......................................................................................................................................... 3.10 3.33Mulch for hydroseeding .............................................................................................................. 3.10 3.34Fertilizer...................................................................................................................................... 3.10 GS (2006 Edition) PageNo. 9 3.35Soil binder................................................................................................................................... 3.11 3.36Stakes, ties and guys ................................................................................................................... 3.11 3.37Protective fabric material ............................................................................................................ 3.11 SUBMISSIONS 3.38Particulars of seed mixture, turf, sprigs, soil conditioner, soil-mix and water ........................... 3.12 3.39Particulars of hydroseeding ........................................................................................................ 3.12 3.40Samples of materials ................................................................................................................... 3.13 HANDLING, STORAGE AND TRANSPORT 3.41Handling and storage of rootballed stock ................................................................................... 3.13 3.42Handling and storage of container grown and containerised stock ............................................ 3.13 3.43Transport of plants ...................................................................................................................... 3.13 3.44Storage of plants ......................................................................................................................... 3.14 3.45Storage of trees and shrubs ......................................................................................................... 3.14 3.46Handling and storage of turf and sprigs ...................................................................................... 3.14 3.47Storage of grass seed .................................................................................................................. 3.14 3.48Storage of fertilizer ..................................................................................................................... 3.14 PRE-PLANTING WORKS 3.49Preparatory works ....................................................................................................................... 3.14 3.50Cleaning ground ......................................................................................................................... 3.14 3.51Ripping ....................................................................................................................................... 3.14 3.52Contaminated ground ................................................................................................................. 3.14 3.53Soiling ......................................................................................................................................... 3.14 3.54Cultivation .................................................................................................................................. 3.15 3.55Scarifying.................................................................................................................................... 3.15 3.56Protection of prepared ground .................................................................................................... 3.15 3.57Removal of material ................................................................................................................... 3.15 PLANTING 3.58General........................................................................................................................................ 3.15 3.59Use of excavated material ........................................................................................................... 3.16 3.60Planting ....................................................................................................................................... 3.16 3.61Staking, tying and guying ........................................................................................................... 3.16 3.62Mulching ..................................................................................................................................... 3.16 3.63Notch planting of seedlings ........................................................................................................ 3.16 3.64Pit planting of seedlings, shrubs, whips, climbers, ground covers and herbaceous plants ......... 3.16 3.65Pit planting of light standard trees andstandard trees ............................................................. 3.17 3.66Pit planting of heavy standard tree and semi-mature trees ......................................................... 3.17 3.67Pit planting of bamboo, conifers and palms ............................................................................... 3.18 3.68Pit planting on slopes .................................................................................................................. 3.18 GRASSING 3.69Hydroseeding .............................................................................................................................. 3.18 3.70Hydroseeding cover .................................................................................................................... 3.18 3.71Surface conditions for hydroseeding .......................................................................................... 3.18 3.72Application of hydroseeding....................................................................................................... 3.18 3.73Protective material ...................................................................................................................... 3.19 3.74Patching up ................................................................................................................................. 3.19 3.75Post-planting fertilizer ................................................................................................................ 3.19 GS (2006 Edition) PageNo. 10 3.76Turfing ........................................................................................................................................ 3.19 3.77Sprigging .................................................................................................................................... 3.19 3.78Completion of turfing and sprigging .......................................................................................... 3.20 ESTABLISHMENT WORKS 3.79Establishment works ................................................................................................................... 3.20 3.80Inspection of establishment works .............................................................................................. 3.20 3.81Replacement of plants and grass ................................................................................................. 3.20 3.82Security of stakes, ties and guys ................................................................................................. 3.20 3.83Firming up plants ........................................................................................................................ 3.21 3.84Watering ...................................................................................................................................... 3.21 3.85Weeding ...................................................................................................................................... 3.21 3.86Pruning........................................................................................................................................ 3.21 3.87Grass cutting ............................................................................................................................... 3.22 3.88Litter collection ........................................................................................................................... 3.22 3.89Post-planting fertilizer ................................................................................................................ 3.22 3.90Control of pests, fungi and disease ............................................................................................. 3.23 3.91Forking over ............................................................................................................................... 3.23 3.92Mulching ..................................................................................................................................... 3.23 3.93Completion of work .................................................................................................................... 3.23 TESTING: GRASS COVER 3.94Testing: grass cover .................................................................................................................... 3.24 3.95Compliance criteria: grass cover ................................................................................................ 3.24 3.96Non-compliance: grass cover ..................................................................................................... 3.24 TREE TRANSPLANTING 3.97Transplanting of existing trees .................................................................................................... 3.24 SECTION 4 FENCING GENERAL 4.01General requirements .................................................................................................................... 4.3 4.02Handrailing ................................................................................................................................... 4.3 4.03Earthworks .................................................................................................................................... 4.3 4.04Pedestrian guardrailing ................................................................................................................. 4.3 4.05Formwork and finishes to concrete ............................................................................................... 4.3 4.06Reinforcement .............................................................................................................................. 4.3 4.07Concrete ........................................................................................................................................ 4.3 4.08Steelwork ...................................................................................................................................... 4.3 4.09Vehicular parapets ......................................................................................................................... 4.3 MATERIALS 4.10Wire .............................................................................................................................................. 4.3 4.11Chain link fence ............................................................................................................................ 4.3 4.12Timber........................................................................................................................................... 4.3 4.13Steel .............................................................................................................................................. 4.3 GS (2006 Edition) PageNo. 11 4.14Bolts, nuts, washers and fittings ................................................................................................... 4.4 FABRICATION OF FENCING 4.15Fabrication of steelwork ............................................................................................................... 4.4 4.16Galvanizing to steel ...................................................................................................................... 4.4 4.17Welding steel ................................................................................................................................ 4.4 POSTS AND GATES FOR FENCING 4.18Concrete posts ............................................................................................................................... 4.5 4.19Gates ............................................................................................................................................. 4.5 SUBMISSIONS 4.20Particulars of fencing .................................................................................................................... 4.5 4.21Samples of materials ..................................................................................................................... 4.5 STORAGE OF MATERIALS 4.22Storage of fencing ......................................................................................................................... 4.5 ERECTING FENCING 4.23Alignment of fencing .................................................................................................................... 4.5 4.24Posts for fencing ........................................................................................................................... 4.6 4.25Erecting posts for fencing ............................................................................................................. 4.6 4.26Fixing wire for fencing ................................................................................................................. 4.6 4.27Fixing gates................................................................................................................................... 4.7 TOLERANCES 4.28Tolerances: fencing ....................................................................................................................... 4.7 SECTION 5 DRAINAGE WORKS GENERAL 5.01General requirements .................................................................................................................... 5.3 5.02Metalwork ..................................................................................................................................... 5.3 5.03Earthworks .................................................................................................................................... 5.3 5.04Formwork ..................................................................................................................................... 5.3 5.05Concrete ........................................................................................................................................ 5.3 5.06Materials for grout ........................................................................................................................ 5.3 5.07Water supply pipeworks ............................................................................................................... 5.3 5.08Cable duct systems ....................................................................................................................... 5.3 5.09Recycled Aggregates .................................................................................................................... 5.3 GLOSSARY OF TERMS 5.10Pipes ............................................................................................................................................. 5.3 GS (2006 Edition) PageNo. 12 MATERIALS 5.11Precast concrete pipes and fittings ................................................................................................ 5.3 5.12Vitrified clay pipes and fittings ..................................................................................................... 5.3 5.13DI pipes and fittings ..................................................................................................................... 5.4 5.14Grey iron pipes and fittings .......................................................................................................... 5.4 5.15uPVC pipes and fittings ................................................................................................................ 5.4 5.16GI pipes and fittings ..................................................................................................................... 5.4 5.17Bolts, nuts and washers ................................................................................................................ 5.5 5.18Elastomeric joint rings .................................................................................................................. 5.6 5.19Detachable couplings and flange adapters .................................................................................... 5.6 5.20Anticorrosion tape ........................................................................................................................ 5.6 5.21Bituminous coatings ..................................................................................................................... 5.7 5.22Aggregates for granular bed and granular fill ............................................................................... 5.8 5.23J oint filler and compressible padding ........................................................................................... 5.8 5.24Polyethylene sheeting ................................................................................................................... 5.8 5.25Precast concrete manholes ............................................................................................................ 5.8 5.26Chambers and gullies .................................................................................................................... 5.9 5.27Step irons ...................................................................................................................................... 5.9 5.28Manhole covers, gully gratings and kerb overflow weirs ............................................................. 5.9 5.29Penstocks .................................................................................................................................... 5.11 5.30Gate valves ................................................................................................................................. 5.12 5.31Flap valves .................................................................................................................................. 5.12 5.32Sludge valves .............................................................................................................................. 5.12 5.33Air valves .................................................................................................................................... 5.13 5.34Fittings for penstocks and valves ................................................................................................ 5.13 5.35Filling abandoned pipes and manholes ....................................................................................... 5.14 SUBMISSIONS 5.36Particulars of pipes, joints and fittings ....................................................................................... 5.14 5.37Particulars of anticorrosion tape and joint filler ......................................................................... 5.14 5.38Particulars of aggregates for granular bed .................................................................................. 5.15 5.39Particulars of manholes, chambers and gullies ........................................................................... 5.15 5.40Particulars of penstocks and valves ............................................................................................ 5.15 5.41Particulars of foam concrete and PC/PFA grout ......................................................................... 5.16 5.42Particulars of tests ....................................................................................................................... 5.16 5.43Particulars of CCTV inspections ................................................................................................ 5.16 5.44Particulars of diversions of flow ................................................................................................. 5.16 TRANSPORT, HANDLING AND STORAGE OF MATERIALS 5.45Transport, handling and storage of pipes, joints and fittings ...................................................... 5.17 5.46Handling of pipes and fittings..................................................................................................... 5.17 5.47Storage of pipes .......................................................................................................................... 5.17 5.48Storage of anticorrosion tape and joint filler .............................................................................. 5.17 5.49Handling and storage of aggregates for granular bed ................................................................. 5.18 5.50Handling and storage of units for manholes, chambers and gullies ........................................... 5.18 5.51Storage of covers, gratings, weirs penstocks and valves ............................................................ 5.18 EXCAVATION 5.52Excavation .................................................................................................................................. 5.18 GS (2006 Edition) PageNo. 13 LAYING AND BEDDING PIPES 5.53Laying pipes ............................................................................................................................... 5.19 5.54Bedding pipes ............................................................................................................................. 5.20 CUTTING PIPES 5.55Cutting pipes ............................................................................................................................... 5.20 JOINTING PIPES 5.56J ointing pipes .............................................................................................................................. 5.21 5.57Flanged joints ............................................................................................................................. 5.21 5.58Flexible collar joints ................................................................................................................... 5.21 5.59Push-in joints .............................................................................................................................. 5.22 5.60Detachable joints ........................................................................................................................ 5.22 5.61Flange adapters ........................................................................................................................... 5.22 5.62Solvent welded joints .................................................................................................................. 5.22 5.63Screw joints ................................................................................................................................ 5.22 PROTECTION OF JOINTS 5.64Protection of joints ...................................................................................................................... 5.23 REPAIRS TO COATINGS AND LININGS 5.65Repairs to coatings and linings ................................................................................................... 5.23 THRUST AND ANCHOR BLOCKS 5.66Thrust and anchor blocks ............................................................................................................ 5.23 BED, HAUNCH AND SURROUND 5.67Granular bed ............................................................................................................................... 5.24 5.68Concrete bed, haunch and surround ............................................................................................ 5.24 5.69Fill material surround ................................................................................................................. 5.25 TOLERANCES 5.70Tolerances: pipelines for drainage works ................................................................................... 5.25 CONNECTIONS 5.71Connections to structures ............................................................................................................ 5.26 5.72Connections to pipes ................................................................................................................... 5.26 MANHOLES, CHAMBERS, GULLIES AND CHANNELS 5.73Manholes, chambers and gullies ................................................................................................. 5.27 5.74Concrete open channels .............................................................................................................. 5.28 GS (2006 Edition) PageNo. 14 MARKER BLOCKS 5.75Marker blocks ............................................................................................................................. 5.28 INSTALLATION OF PENSTOCKS AND VALVES 5.76Installation of penstocks and valves ........................................................................................... 5.28 PIPES AND MANHOLES TO BE ABANDONED 5.77Pipes and manholes to be abandoned ......................................................................................... 5.28 CLEANING OF PIPELINES 5.78Cleaning of pipelines .................................................................................................................. 5.29 INSPECTION OF PIPELINES 5.79Inspection of pipelines ................................................................................................................ 5.30 5.80Inspection of pipelines by CCTV ............................................................................................... 5.30 TESTING: PIPES FOR DRAINAGE WORKS 5.81Batch: pipes for drainage works ................................................................................................. 5.30 5.82Samples: pipes for drainage works ............................................................................................. 5.30 5.83Testing: pipes for drainage works ............................................................................................... 5.30 5.84Non-compliance: pipes for drainage works ................................................................................ 5.31 TESTING: AGGREGATES FOR GRANULAR BED 5.85Batch: aggregates for granular bed ............................................................................................. 5.31 5.86Samples: aggregates for granular bed ......................................................................................... 5.31 5.87Testing: aggregates for granular bed ........................................................................................... 5.31 5.88Compliance criteria: compaction fraction value ......................................................................... 5.31 TESTING: PRECAST CONCRETE UNITS FOR MANHOLES, CHAMBERS AND GULLIES 5.89Batch: manholes, chambers and gullies ...................................................................................... 5.31 5.90Samples: manholes, chambers and gullies .................................................................................. 5.31 5.91Testing: manholes, chambers and gullies ................................................................................... 5.32 5.92Non-compliance: manholes, chambers and gullies..................................................................... 5.32 TESTING: MANHOLE COVERS, GULLY GRATINGS AND KERB OVERFLOW WEIRS 5.93Batch: covers, gratings and weirs ............................................................................................... 5.32 5.94Samples: covers, gratings and weirs ........................................................................................... 5.32 5.95Testing: covers, gratings and weirs ............................................................................................. 5.32 5.96Compliance criterion: resistance to fracture of covers and gratings ........................................... 5.32 5.97Non-compliance: mass of covers, gratings and weirs................................................................. 5.32 5.98Non-compliance: resistance to fracture of covers and gratings .................................................. 5.32 GS (2006 Edition) PageNo. 15 TESTING: WATERTIGHTNESS OF PENSTOCKS 5.99Testing: watertightness of penstocks .......................................................................................... 5.33 5.100Compliance criteria: watertightness of penstocks ...................................................................... 5.33 5.101Non-compliance: watertightness of penstocks ........................................................................... 5.33 TESTING: GRAVITY PIPELINES FOR DRAINAGE WORKS 5.102Testing: gravity pipelines for drainage works ............................................................................. 5.33 5.103Compliance criteria: gravity pipelines for drainage works ......................................................... 5.34 5.104Non-compliance: gravity pipelines for drainage works .............................................................. 5.35 TESTING: PRESSURE PIPELINES FOR DRAINAGE WORKS 5.105Testing: pressure pipelines for drainage works ........................................................................... 5.35 5.106Compliance criteria: pressure pipelines for drainage works ....................................................... 5.35 5.107Non-compliance: pressure pipelines for drainage works ............................................................ 5.36 REPAIR OF PIPELINES AND CULVERTS BY INTERNAL LINING 5.108General........................................................................................................................................ 5.36 5.109Materials ..................................................................................................................................... 5.36 5.110Design of lining .......................................................................................................................... 5.36 5.111Submissions ................................................................................................................................ 5.36 5.112Installation of lining .................................................................................................................... 5.37 5.113Performance tests on internal lining materials ............................................................................ 5.38 APPENDIX 5.1 CCTV INSPECTION OF PIPELINES 5.1.1Scope .......................................................................................................................................... 5.40 5.1.2Equipment ................................................................................................................................... 5.40 5.1.3Procedure .................................................................................................................................... 5.40 5.1.4Recording of results .................................................................................................................... 5.41 APPENDIX 5.2 DETERMINATION OF THE COMPACTION FRACTION VALUE OF AGGREGATES FOR GRANULAR BED 5.2.1Scope .......................................................................................................................................... 5.42 5.2.2Apparatus .................................................................................................................................... 5.42 5.2.3Procedure .................................................................................................................................... 5.42 5.2.4Calculation .................................................................................................................................. 5.42 5.2.5Reporting of results .................................................................................................................... 5.43 APPENDIX 5.3 DETERMINATION OF THE RESISTANCE TO FRACTURE OF MANHOLE COVERS AND GULLY GRATINGS 5.3.1Scope .......................................................................................................................................... 5.44 5.3.2Equipment ................................................................................................................................... 5.44 5.3.3Procedure .................................................................................................................................... 5.44 5.3.4Reporting of results .................................................................................................................... 5.44 GS (2006 Edition) PageNo. 16 APPENDIX 5.4 TESTS ON GRAVITY PIPELINES FOR DRAINAGE WORKS 5.4.1Scope .......................................................................................................................................... 5.45 5.4.2Equipment ................................................................................................................................... 5.45 5.4.3Procedure: before tests and inspections ...................................................................................... 5.45 5.4.4Procedure: water test .................................................................................................................. 5.45 5.4.5Procedure: air test ....................................................................................................................... 5.46 5.4.6Procedure: visual inspection ....................................................................................................... 5.46 5.4.7Procedure: infiltration test .......................................................................................................... 5.46 5.4.8Calculation .................................................................................................................................. 5.46 5.4.9Reporting of results .................................................................................................................... 5.46 APPENDIX 5.5 TESTS ON PRESSURE PIPELINES FOR DRAINAGE WORKS 5.5.1Scope .......................................................................................................................................... 5.47 5.5.2Equipment ................................................................................................................................... 5.47 5.5.3Procedure .................................................................................................................................... 5.47 5.5.4Calculation .................................................................................................................................. 5.48 5.5.5Reporting of results .................................................................................................................... 5.48 SECTION 6 EARTHWORKS GENERAL 6.01Reclamation .................................................................................................................................. 6.3 6.02Trip-ticket System ........................................................................................................................ 6.3 GLOSSARY OF TERMS 6.03Areas of fill ................................................................................................................................... 6.3 6.04Earthworks final surface ............................................................................................................... 6.3 6.05Inert construction and demolition material ................................................................................... 6.3 6.06Earthworks material ...................................................................................................................... 6.3 6.07Formation...................................................................................................................................... 6.3 6.08Intermediate areas of fill ............................................................................................................... 6.3 MATERIALS 6.09Fill material................................................................................................................................... 6.3 SUBMISSIONS 6.10Particulars of earthworks .............................................................................................................. 6.5 6.11Particulars of blasting ................................................................................................................... 6.6 GENERAL EARTHWORKS REQUIREMENTS 6.12Ownership of earthworks material ................................................................................................ 6.6 6.13Temporary Works for earthworks ................................................................................................. 6.7 GS (2006 Edition) PageNo. 17 6.14Handling and storage of earthworks material ............................................................................... 6.7 6.15Protection from water and weather ............................................................................................... 6.7 6.16Earthworks material allowed to become unsuitable or to deteriorate ........................................... 6.7 6.17Additional excavation and stabilisation ........................................................................................ 6.8 6.18Removal of earthworks material ................................................................................................... 6.8 EXCAVATION 6.19Disposal of excavated material ..................................................................................................... 6.8 6.20Use of excavated material ............................................................................................................. 6.8 6.21Obstructions in excavations .......................................................................................................... 6.9 6.22Excavation .................................................................................................................................... 6.9 6.23Excavations adjacent to structures and utilities ............................................................................ 6.9 6.24Excavations for structures, pits and trenches ................................................................................ 6.9 BLASTING TRIALS 6.25Blasting trials ................................................................................................................................ 6.9 6.26Controlled blasting trials ............................................................................................................ 6.10 6.27Results of blasting trials ............................................................................................................. 6.10 6.28Commencement of blasting ........................................................................................................ 6.10 6.29Changes in blasting procedure .................................................................................................... 6.10 BLASTING 6.30Statutory requirements for blasting............................................................................................. 6.10 6.31Recording vibrations due to blasting .......................................................................................... 6.10 6.32Preparatory work for blasting ..................................................................................................... 6.11 6.33Notification of blasting ............................................................................................................... 6.11 6.34Storage of explosives .................................................................................................................. 6.11 6.35Restrictions on blasting times ..................................................................................................... 6.11 6.36Blasting ....................................................................................................................................... 6.11 6.37Controlled blasting ..................................................................................................................... 6.12 DEPOSITION OF FILL MATERIAL 6.38Types of fill material ................................................................................................................... 6.13 6.39Sources of fill material ............................................................................................................... 6.13 6.40Surface preparation for fill material ........................................................................................... 6.13 6.41Commencement of deposition of fill material ............................................................................ 6.13 6.42Haulage of fill material ............................................................................................................... 6.13 6.43Deposition of fill material ........................................................................................................... 6.13 6.44Overfilling .................................................................................................................................. 6.14 6.45Deposition of fill material adjacent to structures and utilities .................................................... 6.14 6.46Deposition of rock fill material ................................................................................................... 6.15 6.47Deposition of fill material in excavations for structures, pits and trenches ................................ 6.15 COMPACTION OF FILL MATERIAL 6.48Compaction of fill material ......................................................................................................... 6.15 6.49Moisture content of fill material ................................................................................................. 6.15 6.50Compaction of fill material adjacent to structures and utilities .................................................. 6.15 6.51Compaction of rock fill material ................................................................................................. 6.15 6.52Compaction of general fill material with a large portion of coarse material .............................. 6.16 GS (2006 Edition) PageNo. 18 COMPLETION OF EARTHWORK SURFACES 6.53Completion of earthwork final surfaces ..................................................................................... 6.17 6.54Completion of formations ........................................................................................................... 6.17 6.55Protection of earthwork final surfaces and formations ............................................................... 6.18 INTERMEDIATE AREAS OF FILL 6.56Deposition of fill material in intermediate areas of fill .............................................................. 6.18 6.57Compaction of fill material in intermediate areas of fill ............................................................ 6.18 EARTHWORKS IN PUBLIC FILLING AREA 6.58Public filling area ........................................................................................................................ 6.18 6.59Public fill .................................................................................................................................... 6.18 6.60Combined reception and exit offices .......................................................................................... 6.18 6.61Reception areas, queuing areas and access roads ....................................................................... 6.20 6.62Management of dump truck movements .................................................................................... 6.20 6.63Temporary haul roads and drains ................................................................................................ 6.21 6.64Handling and storage of wet soil ................................................................................................ 6.21 6.65Deposition of public fill .............................................................................................................. 6.21 6.66Compaction of public fill ............................................................................................................ 6.21 6.67Use of fill material adjacent to structures and utilities in public filling area .............................. 6.24 TOLERANCES 6.68Tolerances: earthworks final surfaces and formations ................................................................ 6.25 TESTING: FILL MATERIAL - GENERAL REQUIREMENTS 6.69Batch: fill material ...................................................................................................................... 6.26 6.70Samples: fill material .................................................................................................................. 6.26 TESTING: FILL MATERIAL - PARTICLE SIZE DISTRIBUTION, LIQUID LIMIT, PLASTICITY INDEX, COEFFICIENT OF UNIFORMITY AND SULPHATE CONTENT 6.71Samples: particle size distribution, liquid limit, plasticity index, coefficient of uniformity, sulphate content .......................................................................................................................... 6.26 6.72Testing: particle size distribution, liquid limit, plasticity index, coefficient of uniformity, sulphate content .......................................................................................................................... 6.27 6.73Non-compliance: particle size distribution, liquid limit, plasticity index, coefficient of uniformity, sulphate content ....................................................................................................... 6.27 TESTING: FILL MATERIAL - OPTIMUM MOISTURE CONTENT AND MAXIMUM DRY DENSITY 6.74Samples: optimum moisture content, maximum dry density ..................................................... 6.28 6.75Testing: optimum moisture content, maximum dry density ....................................................... 6.28 6.76Consistency: optimum moisture content, maximum dry density ............................................... 6.28 TESTING: FILL MATERIAL - MOISTURE CONTENT 6.77Samples: moisture content .......................................................................................................... 6.29 GS (2006 Edition) PageNo. 19 6.78Testing: moisture content ............................................................................................................ 6.29 6.79Compliance criteria: moisture content ........................................................................................ 6.29 6.80Non-compliance: moisture content ............................................................................................. 6.29 TESTING: FILL MATERIAL - RELATIVE COMPACTION 6.81Testing: relative compaction ....................................................................................................... 6.30 6.82Compliance criterion: relative compaction ................................................................................. 6.31 6.83Non-compliance: relative compaction ........................................................................................ 6.31 APPENDIX 6.1 TEST METHODS FOR FILL MATERIAL 6.1.1General........................................................................................................................................ 6.32 6.1.2Terms and symbols ..................................................................................................................... 6.32 6.1.3Grouping of material .................................................................................................................. 6.32 APPENDIX 6.2 DETERMINATION OF THE MOISTURE CONTENT OF FINE GRAINED AND MEDIUM GRAINED MATERIAL BY THE MICROWAVE OVEN DRYING METHOD 6.2.1Scope .......................................................................................................................................... 6.33 6.2.2Apparatus .................................................................................................................................... 6.33 6.2.3Procedure .................................................................................................................................... 6.33 6.2.4Calculation .................................................................................................................................. 6.34 6.2.5Reporting of results .................................................................................................................... 6.34 APPENDIX 6.3 DETERMINATION OF THE MAXIMUM CONVERTED BULK DENSITY BY THE HILF METHOD 6.3.1Scope .......................................................................................................................................... 6.35 6.3.2Apparatus .................................................................................................................................... 6.35 6.3.3Procedure .................................................................................................................................... 6.35 6.3.4Calculation .................................................................................................................................. 6.38 6.3.5Reporting of results .................................................................................................................... 6.39 APPENDIX 6.4 ADJUSTMENT OF THE MAXIMUM CONVERTED BULK DENSITY FOR THE DETERMINATION OF THE RELATIVE COMPACTION 6.4.1Scope .......................................................................................................................................... 6.40 6.4.2Apparatus .................................................................................................................................... 6.40 6.4.3Procedure .................................................................................................................................... 6.40 6.4.4Calculation .................................................................................................................................. 6.41 6.4.5Reporting of results .................................................................................................................... 6.41 GS (2006 Edition) PageNo. 20 SECTION 7 GEOTECHNICAL WORKS PART 1: GENERAL REQUIREMENTS GENERAL 7.01General requirements .................................................................................................................... 7.3 7.02Site clearance ................................................................................................................................ 7.3 7.03Drainage works ............................................................................................................................. 7.3 7.04Earthworks .................................................................................................................................... 7.3 7.05Concrete ........................................................................................................................................ 7.3 7.06Prestressed ground anchors........................................................................................................... 7.3 7.07Reinforced fill structures .............................................................................................................. 7.3 TRIALS 7.08Trials for geotechnical works ....................................................................................................... 7.3 PART 2: GROUND INVESTIGATION GLOSSARY OF TERMS 7.09Block Sample ................................................................................................................................ 7.4 7.10Bulk Sample ................................................................................................................................. 7.4 7.11Inspection Pit ................................................................................................................................ 7.4 7.12J ar Sample..................................................................................................................................... 7.4 7.13Sample .......................................................................................................................................... 7.4 7.14Slope Surface Stripping ................................................................................................................ 7.4 7.15Trial Pit ......................................................................................................................................... 7.4 7.16Trial Trench .................................................................................................................................. 7.4 7.17U76/U100 Sample ........................................................................................................................ 7.4 7.18Undisturbed Soil Sample .............................................................................................................. 7.4 7.19Ground Investigation .................................................................................................................... 7.4 7.20Ground Investigation Site ............................................................................................................. 7.4 7.21Investigation Station ..................................................................................................................... 7.4 7.22Common Ground .......................................................................................................................... 7.4 7.23Rock .............................................................................................................................................. 7.4 7.24Boulders ........................................................................................................................................ 7.4 7.25Cobbles ......................................................................................................................................... 7.4 7.26Gravel ........................................................................................................................................... 7.5 7.27Hard Strata .................................................................................................................................... 7.5 7.28AGS Digital Format ...................................................................................................................... 7.5 SUBMISSIONS 7.29Particulars of ground investigation ............................................................................................... 7.5 INSPECTION PITS, TRIAL PITS AND SLOPE SURFACE STRIPPING 7.30Inspection pits ............................................................................................................................... 7.5 7.31Trial pits and trial trenches ........................................................................................................... 7.5 7.32Pumping from trial pits and trial trenches .................................................................................... 7.6 GS (2006 Edition) PageNo. 21 7.33Backfilling of inspection pits, trial pits or trial trenches ............................................................... 7.6 7.34Slope surface protection stripping ................................................................................................ 7.7 7.35Access ........................................................................................................................................... 7.7 7.36Protection of stripped surface ....................................................................................................... 7.7 7.37Reinstatement of stripped surface ................................................................................................. 7.7 7.38Disturbed samples from trial pits, trial trenches or slope stripping .............................................. 7.8 7.39Records of inspection pits ............................................................................................................. 7.8 7.40Records of trial pits and trial trenches .......................................................................................... 7.8 7.41Photographs of trial pits or trial trenches ...................................................................................... 7.9 7.42Slope stripping records ................................................................................................................. 7.9 DRILLING FOR GROUND INVESTIGATION 7.43Drilling rigs for ground investigation ......................................................................................... 7.10 7.44Drilling equipment for ground investigation .............................................................................. 7.10 7.45Drilling for ground investigation ................................................................................................ 7.11 7.46Categories of core drilling .......................................................................................................... 7.12 7.47Rotary open hole drilling ............................................................................................................ 7.12 7.48Air-Foam Drilling ....................................................................................................................... 7.12 7.49Disposal of flush returns ............................................................................................................. 7.12 7.50Backfilling of drillholes and rotary open holes .......................................................................... 7.12 7.51Sampling from drillholes ............................................................................................................ 7.13 7.52Records of drillholes ................................................................................................................... 7.13 SAMPLING FOR GROUND INVESTIGATION 7.53Supply of sampling equipment and containers ........................................................................... 7.14 7.54General sampling requirements .................................................................................................. 7.14 7.55Numbering and labelling of samples .......................................................................................... 7.15 7.56Sealing of common ground tube samples ................................................................................... 7.15 7.57Core boxes .................................................................................................................................. 7.16 7.58Delivery and storage of samples ................................................................................................. 7.16 7.59Undisturbed tube sampling of common ground in drillholes ..................................................... 7.16 7.60Retractable triple tube core sampling ......................................................................................... 7.16 7.61Piston sampling ........................................................................................................................... 7.18 7.62U100 and U76 sampling ............................................................................................................. 7.18 7.63Block samples ............................................................................................................................. 7.20 7.64Recovery of cores ....................................................................................................................... 7.20 7.65Extrusion and handling of cores ................................................................................................. 7.21 7.66Photographs of core boxes .......................................................................................................... 7.21 7.67Groundwater samples ................................................................................................................. 7.22 IN-SITU TESTING 7.68Standard penetration tests ........................................................................................................... 7.22 7.69Dynamic probe tests ................................................................................................................... 7.24 7.70Vane shear tests ........................................................................................................................... 7.24 7.71In situ density tests ..................................................................................................................... 7.25 7.72Falling or rising head permeability test ...................................................................................... 7.25 7.73Response test .............................................................................................................................. 7.26 7.74Constant head permeability test .................................................................................................. 7.26 7.75Packer (water absorption) test .................................................................................................... 7.27 7.76Impression packer tests ............................................................................................................... 7.28 7.77Inclination and bearing measurements ....................................................................................... 7.28 GS (2006 Edition) PageNo. 22 REPORTS FOR GROUND INVESTIGATION 7.78General........................................................................................................................................ 7.28 7.79Site log book ............................................................................................................................... 7.28 7.80Daily site records ........................................................................................................................ 7.29 7.81Preliminary records ..................................................................................................................... 7.29 7.82Submission of Final Field Work Report ..................................................................................... 7.29 7.83Submission of digital image of Final Field Work Report ........................................................... 7.30 PART 3: SLOPE TREATMENT WORKS MATERIALS 7.84Cement mortar ............................................................................................................................ 7.31 7.85Rock for masonry infilling.......................................................................................................... 7.31 7.86Soil-cement ................................................................................................................................. 7.31 7.87Aggregates for sprayed concrete ................................................................................................ 7.31 7.88Reinforcement for sprayed concrete ........................................................................................... 7.31 7.89Protective mesh and fixings ........................................................................................................ 7.31 7.90Rock bolts ................................................................................................................................... 7.32 7.91Grout for rock bolts .................................................................................................................... 7.32 7.92Rock dowels ............................................................................................................................... 7.32 7.93Grout for rock dowels ................................................................................................................. 7.32 7.94Soil nails ..................................................................................................................................... 7.32 7.95Soil nails with double-corrosion protection ................................................................................ 7.33 7.96Grout for soil nails ...................................................................................................................... 7.34 7.97Non-biodegradable mats for erosion control .............................................................................. 7.34 7.98Biodegradable mats for erosion control ...................................................................................... 7.34 7.99Wire mesh for erosion control .................................................................................................... 7.34 SUBMISSIONS 7.100Particulars of access .................................................................................................................... 7.35 7.101Particulars of sprayed concrete ................................................................................................... 7.35 7.102Particulars of rock bolts .............................................................................................................. 7.36 7.103Samples of materials ................................................................................................................... 7.36 7.104Soil nails ..................................................................................................................................... 7.36 7.105Mats for erosion control ............................................................................................................. 7.37 7.106Wire mesh for erosion control .................................................................................................... 7.38 PRELIMINARY WORKS 7.107Access to slopes .......................................................................................................................... 7.38 7.108Protection fences and barriers ..................................................................................................... 7.38 7.109Preparation for slope treatment works ........................................................................................ 7.39 ROCK SLOPE TREATMENT WORKS 7.110Scaling and trimming of rock slopes .......................................................................................... 7.39 7.111Rock splitting .............................................................................................................................. 7.39 7.112Removal of boulders ................................................................................................................... 7.39 7.113Sealing and infilling of rock joints