1st phase analysis

PROJECT REPORT

on

ANALYSIS AND DESIGN OF UNDERGROUND DRAINAGE SYSTEM IN SRM UNIVERSITY KATTANKULATHUR CAMPUS (HOSTELS)

Submitted in partial fulfillment for the award of the degree

of

BACHELOR OF TECHNOLOGY

in

CIVIL ENGINEERING

by

ROHIT SAHAI 1011010177

Under the guidance of

Mr. J. Rajprasad

(Assistant Professor)

DEPARTMENT OF CIVIL ENGINEERING

FACULTY OF ENGINEERING AND TECHNOLOGY

SRM UNIVERSITY

(Under section 3 of UGC Act 1956)

SRM Nagar, Kattankulathur- 603203

Kancheepuram District

APRIL 201

1

TABLE OF CONTENT

CHAPTER TITLE PAGE

ABSTRACT iv

ACKNOWLEDGEMENT v

LIST OF TABLES viii

LIST OF FIGURES ix

ABBRIVATIONS x

1 OVERVIEW 1

1.1 OBJECTIVE 1

1.2 NECESSITY 1

1.3 SCOPE 1

1.4 METHODOLOGY 2

1.5 MAJOR DESIGN EXPERIENCE 2

1.6 REALISTIC DESIGN CONSTARINTS 2

1.7 REFERNCE TO CODES AND STANDARDS 3

1.8 APPLICATION OF EARLIER COURSE WORKS 3

1.9 MULTIDISCIPLINARY AND TEAM WORK 4

1.10 SOFTWARE USED 4

2 INTRODUCTION 5

2.1 GENERAL 5

2.2 LITERATURE RIVIEW 5

2

2.2.1 Soil profile 6

2.2.2 Effects of drainage 6

2.2.3 Hydrology 6

2.2.4 Annual drain flow 6

2.3 SUMMARY 6

3 OBJECTIVES AND SCOPE 8

3.1 OBJECTIVE AND SCOPE 8

3.2 CATCHMENT AREA 9

3.3 STORM DRAINAGE AND STANDARD POLICIES 9

3.4 SITE SELECTION 10

3.5 PREVIOUS YEAR STUDIES 11

3.6 DATA COLLECTED 11

3.7 POPULATION FORECAST AND AVERAGE DRY

WEATHER FLOW

14

3.8 PERCAPITA CONSUMPTION OF WATER 15

3.9 WASTE WATER CHARACTERSTICS 15

3.10 STORM WATER DRAINAGE 17

3.11 RUNOFF DEPTH 17

3.12 RUNOFF RATE 18

3.13 PIPE MATERIAL 24

3.13.1 Vitrified clay pipes 25

3.13.2 Properties of vitrified clay pipes 26

3.13.3 Economic considerations 28

3

3.14 JOINTS 29

3.14.1 Assemblies 29

3.15 SAFETY ISSUES 30

4 RESULTS AND DISCUSSIONS 31

4.1 BASIC INFORMATION 31

4.1.1 Preliminary Investigation for Design of Sewer System 31

4.1.2 Detailed Survey 32

4.1.3 Profile of Sewer System 32

4.2 SEWER CONSTRUCTION 38

4.3 LAYING OF PIPE SEWERS 40

4.3.1 Depth of flow 40

4.4 TRENCH DESIGN 44

4.4.1 Trench condition 44

4.4.2 Load producing forces 45

4.4.3 Load calculations 45

4.4.4 Type of bedding 46

4.5 PIPE DIMENSIONS 49

4.5.1 Spigot 50

4.5.2 Bends 51

4.5.3 Tees 52

4.6 MANHOLES 53

4.6.1 Junction manholes 53

4

4.6.2 Spacing of manholes 54

4.6.3 Size of manholes 54

4.6.4 Construction 54

4.6.5 Safety measures 56

4.7 COST ESTIMATION AS PER QUANTITY 58

4.8 ABSTRACT ESTIMATE 60

5 CONCLUSION 61

5.1 CONCLUSION

61

5.2 FUTURE SCOPE OF THE PROJECT 61

REFERENCES 62

5

LIST OF TABLES

TABLE TITLE PAGE

1.1 Reference to codes and standard 3

1.2 The application of earlier course work 3

3.1 The rainfall data for last five years in Kanchipuram district 12

3.2 The water consumption data in hostel blocks 14

3.3 The designed sewage flow 16

3.4 The annual rainfall depth 18

3.5 The drainage area with soil type 19

3.6 The runoff curve number (CN) 19

3.7 The slope adjustment factor 24

3.8 The different types of pipe material 25

3.9 The mechanical properties 27

3.10 The angular deflection (after 5mm draw) 29

4.1 Tabulation of the calculated pipe diameter 39

4.2 Peak flow to facilitate the hydraulic properties 41

4.3 Slope and length of the open channel 43

4.4 Weight of 650 mm diameter pipe 46

4.5 Spigot dimensions as per manual 50

4.6 Bends dimensions as per manual 51

4.7 Tees dimensions as per manual 53

4.8 Cost estimation of underground drainage system 58

4.9 Abstract estimation of underground drainage system 60

6

LIST OF FIGURES

FIGURE TITLE PAGE

3.1 Methodology followed for the project 8

3.2 The campus plan of SRM university 13

3.3 The catchment area of SRM hostels 17

3.4 The hydraulic length and drainage area relationship. 21

3.5 The discharge Vs equivalent drainage area for average

watershed slope 5 %

22

3.6 The peak discharge adjustment factor for impervious area 23

3.7 The vitrified clay pipes 26

3.8 The biological induced H2S corrosion 27

3.9 The economic viability and service life 38

3.10 The jointing system C and F 39

4.1 Flow of water at a lower level. 32

4.2 Most economical open channel 41

4.3 Dimensions of open channel 43

4.4 Free body diagram of sewer 45

4.5 Bedding dimensions 47

4.6 Class B bedding 47

4.7 Bedding dimensions for 650mm diameter pipe 48



4.10 Spigot 50

4.11 90° Bend 51

4.12 Tees 52

4.13 Typical illustration of circular manhole 55

4.14 Pipes, Bends and tees nomenclature 57

7

ABBREVIATIONS

A - Cross section area of pipe.

ADWF - Average dry water flow

b - Width of channel

B - Width of trench

C - Dimension coefficient that measures the effect

Cd - Load coefficient

CN - Runoff curve number

d - Depth of flow

LID - Low impact development

n - Manning’s coefficient

p - Average annual depth of rainfall

PVC - Polyvinyl chloride

Qa - average dry weather flow

qa - Total water consumption

q - Water consumption

Q - Design peak flow

R - Runoff depth

W - Load on pile

w - Weight of soil

8

WL - Load on pi

BONAFIDE CERTIFICATE

Certified that this project report titled ANALYSIS AND DESIGN

OF UNDERGROUND DRAINAGE SYSTEM IN SRM

UNIVERSITY KATTANKULATHUR CAMPUS is the bonafide

work of ROHIT SAHAI (1011010177), who carried out the project

under my supervision. Certified further, that to the best of my knowledge

the work reported herein does not form part of any other project report or

dissertation on the basis of which a degree or award was conferred on an

earlier occasion or any other candidate.

Signature of the Guide

Mr.J.RAJ PRASADAsst.Professor O.G.Department of Civil EngineeringSRM UniversityKattankulathur- 603203

Signature of the HOD

Dr. R. ANNADURAIProfessor & HeadDepartment of Civil EngineeringSRM UniversityKattankulathur- 603203

INTERNAL EXAMINER EXTERNAL EXAMINER

DATE:

9

ABSTRACT

This project was done primarily to present an alternate solution for

the problem caused due to open channel drainage system in SRM

University, Kattankulathur campus. This project explores the possibility

of construction of systematic sewerage system which is directly treated

by the treatment plant and the excess storm water which is drained by

providing open channel, making its way to the rainwater collecting

trench. The geographical location of the catchment area is such that it

paves the way for the entire waste water extracted from the hostels.

In this project analysis of waste water is carried out by collecting

the per capita consumption of water and the annual rainfall for last five

years. Pipe networking was done according to Indian Standard code

recommendations using software AutoCAD. The design of pipe

including dimensions, network, and dimensions of trench, slope and

manhole was done manually as per Indian Standard codes. The cost of

the project was estimated as per the latest pricing by PWD and the

abstract cost of the project was calculated. The environmental constraints

were eradicated by undergoing the construction in winters to increase

efficiency and optimum anti-corrosive measures are undertaken. Use

high performance concrete is adopted in order to resolve the

sustainability constraint. Most economical design methods are done

using economically efficient products in order to avoid economical

drawbacks. The project presented the analysis and design of

underground drainage system at SRM University.

10

ACKNOWLEDGEMENT

We would like to place on record, our grateful thanks to Dr.T.P.GANESAN, Pro

Vice Chancellor (P&D), for providing all facilities and help in carrying out this project. We

thank Dr.C.MUTHAMIZHCHELVAN, Director (E&T) for the stimulus provided.

We are extremely grateful to Dr.R.ANNADURAI, Professor and Head, Department

of Civil Engineering for the encouragement and support provided during the project work.

We express our sincere thanks to the coordinator Dr.K.GUNASEKARAN,

Professor, for his valuable suggestions for improvement during project reviews.

Our deepest thanks to MR.J.RAJPRASAD (Asst. Prof, O.G.) for guiding us by

elaborating the analysis process with attention, patience and care. He has taken pain to help

us through the project and make necessary corrections and when needed.

We also thank the staff of SRM DTP section for their efforts in composing the

project report. We record our sincere thanks to our parents for the support and motivation.

Last, but by no means the least, we thank all our friends, who freely helped us in

many ways towards the successful completion of this project work.

ROHIT SAHAI

11

CHAPTER 1

OVERVIEW

1.1 OBJECTIVE

The objective of the project is to construct the underground drainage system

in SRM University (Hostel).

To estimate the total cost of construction.

1.2 NECESSITY

The basic necessities of an underground drainage system are given below.

Drainage of storm water from the surface to avoid settling of water on the

paths.

To induce sanitation foul water with surface rain water to abate the foul

smell.

To facilitate the overall flow in the drainage pipes.

Flooding of surface and subsurface may cause heavy loss of property

(buildings and roads) and health (people and vegetation) of the people residing in the

campus during extremely heavy rains. Hence in order to exterminate such problem

underground drainage system is necessary.

The provision of such a scheme shall ensure a constant, reliable drainage and

reduce environmental pollution.

1.3 SCOPE

The scope of the project is given below.

To gain an understanding of basic excavation techniques.

To test the applicability of perforated pipes.

12

To assess the adequacy of the existing drainage system.

1.4 METHODOLOGY

Literature survey: Books and codes required for the project are collected.

Surveying: Selection of site, study of old drainage system, soil exploration,

type of soil, preparing layout.

Analysis and Design: Analysis of types of pipe material, flow rate, discharge

and estimation total runoff. Design of surface inlet and outlet, manholes, cover,

trenches and pipe network.

1.5 MAJOR DESIGN EXPERIENCE

The project is an “Underground Design Project”. Design experience in the

following areas has been gained during the course of the project.

Design of pipeline network.

Design of manholes.

Design and cost estimation of trenches and pipe laying operations.

1.6 REALISTIC DESIGN CONSTRAINTS

Environmental constraints: Consideration of actual environmental factors

(extreme working temperature, corrosive fluid, abrasive air, etc.) in design.

To overcome the environmental constraints the construction is scheduled in

winters to increase efficiency and optimum anti-corrosive measures are undertaken.

Sustainability constraints: Consideration of sustainability factors in

application of dead and live loads on the underground pipelines.

To overcome these constraints the high performance concrete is used for the

construction.

Economical constraints: Availability of funds for successful completion of

project.

In order to overcome economical constraints, most economical design

methods are adopted using economically efficient products.

1.7 REFERENCE TO CODES AND STANDARDS

13

As far as the codes and standards are concerned, for the design of some

components such as pipe network, trenches and manholes, the Indian Standard (IS)

codes have been used. The various IS codes and standards used for the project are

listed below in the Table 1.1.

Table 1.1 Reference to codes and standard

CODES CONTEXT

IS 2527:1984 Code Of Practice For Fixing Rainwater Gutters And

Downpipes For Roof Drainage (First Revision)

IS 1172:1993 Code Of Basic Requirements For Water Supply, Drainage

And Sanitation (Fourth Revision)

IS 1742:1983 Code Of Practice For Building Drainage (Second Revision))

IS 4111

(Part 1):1986

Code Of Practice For Ancillary Structures In Sewerage

System: Part I Manholes (First Revision)

IRC:SP:42-1994 Guidelines On Road Drainage

1.8 APPLICATION OF EARLIER COURSE WORK

The knowledge gained from some of the earlier courses are used in this

project and are listed in Table 1.2.

Table 1.2 Application of earlier course work

14

COURSE

CODE

COURSE NAME CONTEXT

CE0104 Computer Aided Building

Drawing

Pipe layout and alignment

CE0205 Fluid Mechanics Evaluation of discharge ,inlet

outlet diameter

CE0206 Applied Hydraulic

Engineering

Evaluation of catchment area,

hydrological parameter

CE0306 Foundation Engineering Determination of water Table

and depth of excavation.

Table 1.2 (continued)

CE0307 Environmental

engineering I

Design of pits, manholes, pipe

material, joints

CE0411 Estimation, Costing And

Professional Practice

Estimation and costing

1.9 MULTIDISCIPLINARY COMPONENT AND TEAM WORK

This project involves students in multidisciplinary team work like interacting

with the common people while procuring the dimensions of the streets, evaluation of

ground water Table, chemical and physical properties of the soil with the

maintenance department for the allocation of labor force.

1.10 SOFTWARE USED

The various software used in the project are given below.

AutoCAD

Microsoft Office

SAP

CHAPTER 2

INTRODUCTION

15

2.1 GENERAL

Drainage is the process of interception and removal of water from over, and

under the vicinity of the road surface. Drainage can be surface (where water is

conveyed on the road surface and drainage channels) or subsurface (water flows

underneath the pavement structure).

Surface and subsurface drainage of roads critically affects their structural

integrity, life and safety to users, and is thus important during highway design and

construction. Road designs therefore have to provide efficient means for removal of

this water; hence the need for road drainage designs.

Drainage facilities are required to protect the road against damage from

surface and sub surface water. Traffic safety is also important as poor drainage can

result in dangerous conditions like hydroplaning. Poor drainage can also compromise

the structural integrity and life of a pavement. Drainage systems combine various

natural and a manmade facility e.g. ditches, pipes, culverts, curbs to convey this

water safely (Ref. 1).

2.2 LITERATURE REVIEW

This project demands through the study of terminology and the methods of

construction of an underground drainage system. The required details are collected

from the literature and also from earlier course study that is environmental

engineering are summarized here.

2.2.1 Soil profile

Soil which does not drain quickly and naturally can be improved by the

installation of a subsurface tile drainage system. Tile drainage provides storage

capacity in the soil profile. This storage acts as a reservoir which fills and reduces

surface runoff for low intensity storms (Ref. 1).

2.2.2 Effects of drainage

16

Soil water regimes and water balances are presented for a series of drained

and undrained experimental grassland plots, intended to examine the agronomic

consequences of drainage. The major effect of drainage is to alter the route of water

loss from the site (Ref. 1).

2.2.3 Hydrology

Research conducted for the last 35 years has shown that subsurface drainage

has a significant impact on hydrology and contaminant transport. As a first step

towards incorporating drainage systems into large-scale hydrological models, an

equivalent representation of drains buried in a soil profile by using a homogeneous

anisotropic porous medium without drains (Ref. 1).

2.2.4 Annual drain flow

Drainage water management showed potential for reducing annual average

(1915–2006) drain flow from all drain spacing (10–35 m) regardless of the growing

season operational strategy, with reductions varying between 52% and 55% for the

drain spacing considered. Approximately, 81% to 99% of the annual drain flow

reduction occurred during the non- growing season, depending on the operational

strategy (Ref. 1).

2.3 SUMMARY

The effects of climate variability, drain spacing, and growing season

operational strategy on annual drain flow were studied for a hypothetical drainage

water management system.

Drainage has lowered the water tables, reduced the duration of water logging

in the drained plots and its effects in terms either of the total water quantities leaving

the site or of peak flows is quite small. In order to facilitate easy cleaning in sewer

lines whenever blockage occurs in sewer line, adequate number of manholes is

provided at regular intervals. Manholes with cast iron frames and covers are provided

in heavy traffic roads, on small lanes and cross roads with less traffic with RCC

frames and covers for the manholes.

17

CHAPTER 3

OBJECTIVES AND SCOPE

18

3.1 OBJECTIVE AND SCOPE

Drainage and sewerage system have always been part of essential

infrastructure in modern cities and town. In SRM university separate systems are

provided for collection and disposal of sewage and storm water. These systems are

unsanitary for the environment hence the project intends to provide a sanitary source

of drainage which is underground system which collects the sewage and leads it to

the sewage treatment plant.

Over the past ten years, population in SRM University has increase

significantly. This has led to an increase in water consumption and a consequential

increase in quantity of waste water to be handled. Today our community generates

about 50 million liters per day of waste water daily which required proper collection

and disposal. The methodology followed in the project is shown in Figure 3.1.

Fig. 3.1 Methodology followed in the project

3.2 CATCHMENT AREA

The catchment area of any point is defined by the limits from where surface

runoff will make its way, either by natural or manmade paths, to this point. The

catchment boundary is determined by using the most accurate information available

subject to such information being acceptable to council as appropriate. This is

presented to Council in a contour map along with the source of information.

Catchment area land use is based on current available zoning information or

19

proposed future zonings, where applicable and is produced to reflect both the minor

and major event catchments.

In SRM University the most vulnerable catchment area is the Hostels that

include both boys as well as girls. The quantity of water used per day in this varied

area is peculiarly gigantic (Ref. 2).

3.3 STORM DRAINAGE & GRADING STANDARDS AND POLICIES

All storm water which falls within a development, including the respective

one-half of all abutting streets, shall retain a minimum of the 100 year 2 hour storm

water runoff within the boundaries of said development. Predevelopment runoff

versus post development runoff retention is not acceptable, except for a “first flush”

facility or an approved designated drainage outfall, and shall be approved by the

Public Works Department.

Drainage retention/detention and conveyance systems shall be designed to

eliminate and reduce storm water runoff impact of adjacent or downstream

properties. No storm water drainage system shall be approved if the effect may cause

an increase in peak discharge, volume, or velocity of runoff or change the point of

entry of drainage onto another property during the runoff event.

The institution Civil Department shall require for review and approval a

grading and drainage plan and report be submitted wherever development and/or

grading is proposed within the University limits.

Construction documents for grading and drainage submitted to the University

for approval must be sealed by a registered Professional Civil Engineer. This

registered Professional Civil Engineer shall be held solely responsible for the

correctness and adequacy of all data, drawings, calculations, and reports submitted to

the University for review and approval. Approval by the University does not

necessarily imply that the design is appropriate, or that the development is in strict

compliance with all applicable regulations and standards.

Changes or additions to sites which require a site plan approval shall be

required to address drainage alterations and/or additions on the entire site with

approval of the University and meet storm drainage requirements as set forth in this

project (Ref. 2).

20

3.4 SITE SELECTION

The underground drainage system is located in SRM University, Chennai,

India (shown below in Figure 3.1). The site is at an altitude of 33 m above mean sea

level at latitude 12° 42’ N and longitude of 80°02’ E. The climate is characterized by

a short rain period from mid July to the end of September, a long rain period from

October to mid January, and a long dry period from mid January to mid July. The

climate is tropical, with a temperature variation of 19° - 42° C and average annual

rainfall of 1330 mm (India Meteorological Department, Chennai) (Ref. 2).

Site Planning Low impact development (LID) techniques are incorporated

into redevelopment drainage in SRM University. Exceptions may be made for

incidences where a demonstrated public purpose (such as preserving a historic

resource or a significant natural feature) is found to be served by the permitting

board or agency which would necessitate the use of underground recharge systems.

The site planning process shall be documented and include the following steps:

Perform Site Analysis – The important natural features such as streams and

drainage ways, floodplains, wetlands, recharge groundwater protection areas, high-

permeability soils, steep slopes and erosion-prone soils were identified.

Layout Preferred Development Scenario – Preferred site development layout

that minimizes total impervious area, reflects the existing topography, and uses

existing hydrologic features was prepared.

Create a Decentralized Storm water System management of runoff at the

source to the extent practical through the use of small decentralized structures, such

as infiltration structures, filter strips, rain barrels, cisterns, dry wells, and vegetated

areas was done. The time of concentration (average time for rainfall to reach a point)

by using open, vegetated drainage systems and maximizing overland or sheet flow

was increased as studied in CE0307, Environmental engineering I (Ref. 2).

3.5 PREVIOUS YEAR STUDIES

In SRM hostels around 1mold of sewage is generated daily for carrying the

sewage surface drainage systems are provided around the hostels. Surface drainage

21

system consists of different diameter and length pipes which are made up of different

materials such as cast iron pipe and vitrified clay pipes.

Storm water drainage system is also provided at certain places such as along

the road and in parking lot.

3.6 DATA COLLECTED

The urban heat island effect leads to increased rainfall, both in amounts and

intensity, downwind of cities. Global warming is also causing changes in the

precipitation pattern globally, including wetter conditions across eastern South India

and drier conditions in the tropics. Rainfall is measured using rain gauges. Rainfall

amounts can be estimated by weather radar.

The major cause of rain production is moisture moving along three-

dimensional zones of temperature and moisture contrasts known as weather fronts. If

enough moisture and upward motion is present, precipitation falls from convective

clouds (those with strong upward vertical motion) such as cumulonimbus (thunder

clouds) which can organize into narrow rain bands. In mountainous areas, heavy

precipitation is possible where upslope flow is maximized within windward sides of

the terrain at elevation which forces moist air to condense and fall out as rainfall

along the sides of mountains. On the leeward side of mountains, desert climates can

exist due to the dry air caused by down slope flow which causes heating and drying

of the air mass. The movement of the monsoon trough, or inter tropical convergence

zone, brings rainy seasons to savannah climes.

In planning a drainage system, the following data should be collected to

ensure compatibility with the overall strategic plan and master plans,

Water consumption in each hostel for calculation of sewage discharge

Campus layout plan for calculation of catchment area (shown below in

Figure 3.2).

Rainfall data for runoff calculation (shown below in Table 3.1)

Number of student in hostels

Rainfall data for last five years (Ref. 4).

22

Table 3.1 The rainfall data for last five years in Kanchipuram district

YearJan Feb Mar Apr May Jun

R/f R/f R/f R/f R/f R/f

2008 28.8 18.8 150.9 13.5 18.6 52.2

2009 16 0 6.6 0 43.8 22.3

2010 1 0 0 4.4 91.3 107.9

2011 5.6 36.1 0 55.9 29.8 36.6

2012 7.9 0 0 0.1 5.9 31.6

YearJul Aug Sep Oct Nov Dec

R/f R/f R/f R/f R/f R/f

2008 42 99.7 117.8 312.4 505.7 36.3

2009 48.7 119.7 132 57.9 505.2 174

2010 93.3 209.3 116.1 192 291.9 260.9

2011 121.3 189.9 180 249.1 390.3 181.7

2012 75.1 `141.9 93.8 318.4 95.3 132.6

23

Fig. 3.2 The campus plan of SRM University

24

3.7 POPULATION FORECAST AND AVERAGE DRY WEATHER FLOW

The no. of students residing in hostel is calculated based on the no. of room in

each hostel multiply by no. of student in each room, there are total 13 blocks. (shown

below in Table 3.2) as studied in CE0307, Environmental engineering I.

Average dry weather flow.

The quantity of average dry weather flow is about 80% of the total water

consume in each hostel and mess (Shown below in Table 3.2).

Qa = 80 % of “q” = 0.80 × “q”

Where,

q = water consumption

Qa = average dry weather flow

Table 3.2 The water consumption data in hostel blocks

S.no Name of hostel No. of student/hostel

Water consumption

lpd

Quantity of average dry

weather flow lpd

1 Paari 1000 118602 94881.6

2 Kaari 1000 120303 96242.4

3 Oori 1000 122004 97603.2

4 Adhiyaman 1000 122428 97942.4

5 Nelson mandela 800 58722 46977.6

6 Agasthiyar 600 38398 30718.4

7 Sannasi 450 36394 29115.2

8 Sannasi mess - 26667 21333.6

Girls hostel

9 A block 1000 121603 97282.4

10 B block 1000 115300 92240.0

11 C block 1000 123667 98933.6

12 D block 1000 118749 94999.2

13 Mess - 26890 21572.0

Total X=9850 qa=1149727 Qa=822238.3

25

Total water consumption is given by as recommended by IS 1172:1993 (Ref.

10),

qa = 118602+120303+122004+122428+58722

+38398+36394+26667+121603+115300+

123667+118749+26890

qa = 1149727 lpd

Where,

qa = total water consumption

3.8 PERCAPITA CONSUMPTION OF WATER

The percapita consumption of water is computed by taking the ratio between

the total number of students in the hostel and the total water consumption (Ref. 5).

Total no of students,

X = 1000+1000+1000+1000+800+600+450+

1000+1000+1000+1000

= 9850

Where,

X = total no. of students in hostel

As known,

qa = 1149727 lpd

Therefore, percapita consumption of water,

= q aX

= 1149727

9850

= 117 lpd

3.9 WASTE WATER CHARACTERISTICS

Sewage systems are designed to accommodate peak flows which are

determined from the product of the average dry weather flow (ADWF) and a peak

factor (Pf) (the designed sewage flow shown below in Table 3.3) as studied in

CE0307, Environmental engineering I.

26

Q = Qa × pf

Where,

Q = designed peak flow

Qa = average dry weather flow

Now, Peak factor,

pf = Q a maxQ a avg

From Table 3.2,

Qamax = 98933.6 lpd

Where,

Qaavg = total of avg. dry weather flow / no of blocks

=

94881.6+96242.4+97603.2+97942.4+46977.6+¿30718.4+29115.2+21333.6+97282.4+92240.0+¿98933.6+94999.2+21572.013

= 63249.10 lpd

Peak factor (pf) = 98933.6

63249.10 = 1.5

Designed peak flow = Qa ×1.5

Table 3.3 The designed sewage flow

S.no. Name of hostels Quantity of average dry weather flow

(qa)lpd

Designed peak flow(q)=qa×1.5

Lpd

1 Paari 94881.6 142322.4

2 Kaari 96242.4 144363.6

3 Oori 97603.2 146404.8

4 Adhiyaman 97942.4 146913.6

5 Nelson mandela 46977.6 70466.4

6 Agasthiyar 30718.4 46077.6

7 Sannasi 29115.2 43672.8

8 Sannasi mess 21333.6 32000.4

Girls hostel

9 A block 97282.4 145923.6

10 B block 92240.0 138360.0

11 C block 98933.6 148400.4


27

12 D block 94999.2 142492.8

13 Mess 21572.0 32358.0

Total 822238.3 1233357.45

As shown in the Table 3.3,

Total designed peak flow = 1233357.45 lpd

Q = 1233.36 cu meter/day

3.10 STORM WATER DRAINAGE

Total catchment area of the site is 17.60 acres in that built-up area is 10.32

acres, open space is 5.19 acres, paved area is 2.05 acres and slope is 5% which is

claculated from the campus layout plan (Catchment area is shown below in Figure

3.3) (Ref. 5).

Fig. 3.3 The catchment area of SRM hostels

3.11 RUNOFF DEPTH

Runoff depth is calculated based on annual rainfall data which is shown

above in Table 3.4 as studied in CE0305 Fluid mechanics,

Table 3.4 The annual rainfall depth

28

Sno. Year Annual rainfall depth (cm)

P1 2008 139.6

P2 2009 112.7

P3 2010 136.7

P4 2011 147.6

P5 2012 90.2

P = (P 1+P 2+P 3+P 4+P 5)

5

Therefore,

P = (139.6+112.7+136.7+147.6+90.2)

5

= 125.3 cm.

From the Inglis formula,

R = 0.85P – 30.5 mm

= 0.85 × 125.3 – 30.5

= 76 mm

= 3 inch

Where,

P = Average annual depth of rainfall

R = runoff depth

3.12 RUNOFF RATE

Runoff that occurs on surfaces before reaching a channel is also called a

nonpoint source. If a nonpoint source contains man-made contaminants, the runoff is

called nonpoint source pollution. A land area which produces runoff that drains to a

common point is called a drainage basin.

Using SCS peak discharge method calculation of peak runoff rate is

calculated as recommended by IS 2526:1984 (Ref. 11).

Table 3.5 The drainage area with soil type

29

S.no. Designation Area in acres Type of soil group

a1 Residentail area 10.32 Group D

a2 Open space 5.19 Group B

a3 Paved parking lot and road area 2.05 Group D

A Total area 17.60

Total area of residential,paved parking lot and open space according to their

soil type is shown above in Table 3.5 (Ref. 5).

Soil Group A - Represents soil having a low runoff potential due to high

infiltration rates.

Soil Group B - Represents soils having a moderately low runoff potential

due to moderate infiltration rates.

Soil Group C - Represents soils having a moderately high runoff potential

due to slow infiltration rates. These soils consist primarily of soils in which a layer

exists near the surface that impedes the downward movement of water

Soil Group D - Represents soils having a high runoff potential due to very

slow infiltration rates.

Drainage area A = π r2 by percentage of total area

For residential = 10.32× 100

17.6 = 59 %

For open space = 5.19× 100

17.60 = 30 %

For paved area = 2.05× 100

17.60 = 12 %

Table 3.6 The runoff curve number (CN)Land use/cover Hydrologic soil group

A B C D

good condition: Open spaceGrass cover on 75 % or more of the area

39 61 74 80

fair condition:Grass covers on 50 to 75 % of the area.

49 69 79 84


30

Commercial and business areas (85 % impervious) 89 92 94 95

Industrial districts(72 % impervious) 81 88 91 93

Average lot size Average % Impervious

1/8 acre or less 65 77 85 90 92

1/4acre 38 61 75 83 87

1/3 acre 30 57 72 81 86

1/2 acre 25 54 70 80 85

1 acre 20 51 68 79 84

2 acre 15 47 66 77 81

Paved parking lots, roofs, drive ways, etc.

98 98 98 98

Runoff Curve Number (CN): It is the empirical formula used in hydrology to

calculate direct runoff or infiltration which is shown in Table 3.6 above (Ref. 5).

Using Table 3.6,

For residential, because size of each block is less than 0.125 acres and soil group is

D,

CN1 = 92

For open space, fair condition: grass cover on 50 to 75 % of the area and soil group is

B,

CN2 = 69

For paved area, soil group D,

CN3 = 98

Average curve number (CN) = percentage of drainage area × CN

Residential = 0.59 × 92

= 54.28

Open space = 0.30 × 69

= 20.7

Paved area = 0.12 × 98

= 11.76

Total average CN number = 54.28+20.7+11.76

= 86.7~87

31

Hydraulic length, Figure 3.4 below shows the hydraulic length and drainage

area relationship.

L = 209 × (A) 0.6

Where,

L = hydraulic length, in feet

A = drainage area, in acres

L = 209 × (17.60) 0.6

L = 1170 ft

= 356.61 m

Fig. 3.4 The hydraulic length and drainage area relationship.

Equivalent area,

Using Figure 3.4 as recommended by IS 1742:1983 (Ref. 9),

Using interpolation = 1170 x15

1000

= 17.55 acres

= 71022.33 m2

32

Discharge for equivalent area: for average watershed slopes 3-7% and CN 87

which is shown below in Figure 3.5.

Fig. 3.5 The discharge Vs equivalent drainage area for average slope 5%

Using Figure 3.5 for equivalent drainage area 17.55 acres as recommended by

IS 1742:1983 (Ref. 9).

Q1 = 20 cfs

Peak rate of runoff is Q1 × R

Where,

Q1 = rate discharge for equivalent area per inch

R = runoff depth, inch

Peak rate of runoff = 20 × 3

= 60 cfs

Corrected peak rate of runoff = Q1 × (drainage area/equivalent area)

= 60 × 17.6017.55

Q2 = 60.2 cfs

Where,

Q2 = Corrected peak rate of runoff

33

Q3 = Q2 × impervious factor

Q3 = Adjust peak discharge rate

Impervious factor and peak discharge relationship is shown below in Figure 3.6

Fig. 3.6 The peak Discharge Adjustment Factor for Impervious Area

Using Figure 3.6 as recommended by IS 1742:1983 (Ref. 9),

For impervious area 59 % and CN 87,

Impervious factor is 1.2,

Q3 = 60.2 × 1.2

= 72.24 cfs

Adjust peak discharge for averagage watershed slope,

Q4 = Q3 × slope factor

Q4 = Adjust peak discharge for avg. watershed

Slope factor and drainage area relationship is shown below in Table 3.7 as

recommended by IS 1172:1993 (Ref. 10).

Table 3.7 The slope adjustment factor

Type Slope (present) 10 acres 20 acres 50 acres

34

Flat 0.1 0.49 0.47 0.44

0.2 0.61 0.59 0.56

0.3 0.69 0.67 0.65

0.4 0.76 0.74 0.72

0.5 0.82 0.80 0.78

0.7 0.90 0.89 0.88

1.0 1.0 1.0 1.0

1.5 1.13 1.14 1.14

Moderate 3 0.93 0.92 0.91

4 1.0 1.0 1.0

5 1.04 1.05 1.07

6 1.07 1.10 1.12

7 1.09 1.13 1.18

Using Table 3.7 for 5% slope and area 17.60 acres,

Using interpolation,

Slope factor = 17.60× 1.04

10

= 1.8

Q4 = 72.24 × 1.8

= 130.03 cfs

So designed runoff rate,

Q = 130.03 cfs

Q = 3.7 cu meter/sec

3.13 PIPE MATERIAL

Different type of pipe materials with their properties are shown below in

Table 3.8 (Ref. 6).

Table 3.8 The different types of pipe material

35

Material Concrete plain

reinforcement

Prestressed

concrete

Vitrified clay

Size range DN 150 to DN 300 DN 450 to DN 3000 DN 150 to DN 1200

Normal

working

pressure

Atmospheric

pressure

4 to 12 bar Atmospheric

pressure

Std. Length 0.45 m to 5 m 2.5 m to 6 m 600 mm to 3 m

Impact

resistance

Good Good Good

Service life 100 years 100 years 75 years

Availability Readily available Imported Available in some

specific diameter

Application Wide range of sizes

and strength is

available

Can withstand with

high internal

pressure

Used in small and

medium size sewer

carrying gravity flow

Transportation Not easy Not easy Easy low wt.

Based on our requirement and cost, vitrified clay pipe is chosen. It is resistent

to chemical attacks, corrsion and high internal pressure.

3.13.1 Vitrified clay pipes

These are produced from the raw materials clay, grog (chamotte) and water.

The glaze applied to the products before firing consists of mainly the same basic

components plus metallic oxides for colour. During drying at a temperature of

approx. 110°C most of the water necessary for shaping is extracted. The subsequent

firing at temperatures rising up to 1200°C creates a completely new material by

sintering. This vitrified clay has exceptional properties in respect to chemical

resistance, mechanical strength, impermeability and hardness. Highly developed

manufacturing and preparation techniques have made it possible to upgrade an

already proven product, the consistency is guaranteed by quality control. Vitrified

clay pipes are designed for sewers operating on gravity in municipal and industrial

applications, Figure 3.7 below shows the vitrified clay pipe (Ref. 6).

36

Fig. 3.7 The Figure shows the vitrified clay pipes

3.13.2 Properties of vitrified clay pipes

Chemical resistance

Vitrified clay pipes and fittings are resistant to chemical attack in a pH-range

from 0 - 14.

Biological induced H2S corrosion

The formation of H2S in sewage is a consequence of the natural biological

decomposition of sulphur containing organic and inorganic matter (proteins,

sulphates). H2S mainly forms under anaerobic conditions by sulphate reducing

bacteria (desulfovibrio desulfuricans) in the slime of a matured sewer and to a lesser

extent by bacteriological processes in the sewage. In gravity sewers the formation of

H2S commences after the oxygen originally present in the sewage has been

consumed by manifold biological processes. This is followed by the anaerobic

decomposition with an ever increasing formation of H2S, which slowly escapes into

the sewer atmosphere. Turbulence in the sewage stream increases the escape of the

gaseous H2S. The formation of H2S is supported by long sewage flows, low flow

velocities and high sewage temperatures.

37

The formation of H2S and the oxidation into H2SO by bacteria (Figure 3.8

shows below the biological induced H2S corrosion) living on the moist surface of the

sewer occurs not only in gravity sewers, but also and more severely in pressure pipe

lines, where, due to the absence of an atmosphere, continuously ideal conditions for

the sulphate reducing bacteria prevail. The biological induced H2S-corrosion has its

effects only above the surface level of the sewage stream, where the sulphuric acid

reacts with the lime content of cement-bound pipe materials (Ref. 6).

Fig. 3.8 The Figure shows the biological induced H2S-corrosion

Mechanical resistance

The mechanical resistance of vitrified clay has developed enormously during

the last decades. Nowadays, a vitrified clay pipe up till DN 600 has the same

mechanical strength as reinforced concrete pipes from the series 135, mechanical

properties are shown below in Table 3.9 (Ref. 6).

Table 3.9 The mechanical properties

S.No

. Mechanical Properties Value

1. Specific weight 22 kN/m3

2. Bending tensile strength 15-40 N/mm2

3. Mohs hardness 8

4. Modulus of elasticity 50,000 N/mm2

5. Coefficient of thermal expansion 5x10-6 1/K

6. Thermal conductivity 1-2 W/m.K

Hydraulic capacity

38

Vitrified clay pipes have and hold a smooth inner surface (wall roughness

between 0.02 mm and 0.05 mm). Especially in the case of limited slopes, this offers

quite some advantages. Because of the high erosion resistance, vitrified clay can

even be used for slopes up to 10 m/sec., without any danger of material deterioration

for concrete example, the maximum slope is only 3 m/sec (Ref. 6).

High abrasion resistance

Vitrified clay has high abrasion resistance, which is equally true for the glaze

and the rest of the wall. Abrasion values encountered in the tests are approximately

0.08 mm, which is much lower than the typical abrasion values of 0.2 mm to 0.5 mm

after 100 000 load cycles measured using the Darmstadt test (Ref. 6).

Corrosion resistance

Vitrified clay material is resistant to all types of chemicals over the entire

wall thickness. The resistance of the vitrified clay material and seals is tested using

chemicals, including sulphuric acid at pH 0 and NaOH at pH 14.

3.13.3 Economic consideration

The cost for construction of a sewer line is determined largely by the location

and thetype of construction. Figure 3.9 below shows the economic viability and

service life.The operating and maintenance cost are the basis of the charges levied

for use of the sewer. These costs represent a constant expense (Ref. 6).

Fig. 3.9 The Figure shows the economic viability and service life

3.14 JOINTS

39

It is imperative that tight flexible joints are formed when individual pipes and

fittings are assembled to form sewers. The pipe and joint are part of a unique system

that together ensures easy assembly, reliability and long service life. For this reason

sealing elements are factory installed.jointing systems are shown below in Figure

3.10 (Ref. 6).

Joint “L” to jointing system “F”

Joint “K” to jointing system “C”

Joint “S” to jointing system “C”

Fig. 3.10 The Figure shows the jointing system C and F

3.14.1 Assemblies

These shall remain watertight when tested at internal or external pressures of

5 kPa (0.05 bar) and 50 kPa (0.5 bar). The joint under such internal or external

pressure must not show any visible leakage when further be subjected to Table 3.10

below shows the angular deflection (Ref. 6).

Table 3.10 Angular deflection (after 5 mm draw)

S.No

.

Nominal size

(mm)

Deflection per meter of deflected pipe

length

1 100-200 80 mm

2 250-500 30 mm

3 600-800 20 mm

4 >800 10 mm

Pipes and fittings of the same jointing system, of the same nominal size and

the same pipe class are directly interchangeable. Uniformity of pipe class during

installation is a prerequisite. For all applications it must be observed, that joint

40

assemblies are guaranteed to withstand cyclic temperature changes of -10°C to

+70°C and chemical attacks from normal sewage and other harmful effluents in

concentrations from pH 0 (sulphuric acid) to pH 14 (caustic soda).

3.15 SAFETY ISSUES

Every project has its own particular and distinctive features (e.g. general

arrangement/layout of the works, site location and constraints, accessibility of the

works by the public, etc). It is necessary for the designer to identify all potential

risks arisen from the proposed works and to design the works in such a way as to

remove, reduce and/or control the identified hazards present during the course of

construction, operation, maintenance, and finally decommissioning and demolition.

In general, consideration should be given to the following aspects when carrying out

risk assessment at the design stage,

The anticipated method of construction – site constraints encountered,

technique involved may prove hazardous, plant and materials to be used

carefully.

The operation of works – warning signs, fencing, life buoys, grilles, and

means of emergency communication were established.

The decommissioning and demolition of the works – pre-stressed members

and contaminated grounds were keenly observed.

41

CHAPTER 4

RESULTS AND DISCUSSION

4.1 BASIC INFORMATION

Before the sewer network can be designed, accurate information regarding

the site conditions is essential. This information may vary with the individual scheme

but shall, in general, be covered by the following (Ref. 7).

Site plan - A plan of the site to scale with topographical levels, road

formation levels, level of the outfall, location of wells, underground sumps

and other drinking water sources.

The requirements of local bye-laws.

Subsoil conditions - Subsoil conditions govern the choice of design of the

sewer and the method of excavation.

Location of other services (such as position, depth and size of all other pipes,

mains, cables, or other services, in the vicinity of the proposed work).

Topography.

4.1.1 Preliminary Investigation for Design of Sewer System

The anticipation of future growth in any community in terms of population or

commercial and industrial expansion forms the basis for preparation of plan for

providing the amenities including installation of sewers in the area to be served.

The recommended planning period is 30 years, however, this may vary depending

upon the local conditions. The prospective disposal sites are selected and their

suitability is evaluated with regard to physical practicability for collection of sewage,

effects of its disposal on surrounding environment and cost involved (Ref. 7).

4.1.2 Detailed Survey

The presence of rock or underground obstacles such as existing sewers,

42

water lines, electrical or telephone wires, tunnels, foundations, etc., have significant

effect upon the cost of construction. Therefore, before selecting the final lines and

grades for sewers necessary information regarding such constructions is collected

from various central and state engineering departments (Ref. 7).

4.1.3 Profile of Sewer System

The vertical profile is drawn from the survey notes for each sewer line. The

vertical scale of the longitudinal sections are usually magnified ten times the

horizontal scale. The profile shows ground surface, tentative manhole locations,

grade, size and material of pipe, ground and invert levels and extent of concrete

protection, etc. (Ref. 7).

Design velocity for hostel,

Assuming the velocity of flow at each floor will be same as 'V'.

The diameter of main drainage pipe = 0.40 m.

Now considering difference in head for one floor as shown in the Figure 4.1

as studied in CE0305 Fluid mechanics,

Fig.4.1 Flow of water at a lower level.

Applying Bernoulli's equation at the top of the water surface and at the outlet

of the pipe as recommended by IS: 1172:1993 (Ref. 10).

P1

ρg+

V 12

2 g + Z1 =

P2

ρg+

V 22

2 g +Z2+all losses

P1

ρg,

P2

ρg = Pressure heads

V 12

2 g,V 2

2

2g = Velocity heads

Z1 and Z2 = datum head

43

All losses = major losses + minor losses

Considering datum line passing through the centre of pipe,

0+0+3 = 0+ V 2

2 g+0+ hi+h f

hi = 0.5V 2

2 g

hf = 4 × F × L × v2

d × 2 g

F = 0.009 for vitrified clay pipe

3 = V2

2 g + 0.5V 2

2 g +4 × F × L × v2

d × 2g

3 = V 2

2 g×[1+0.5+ 4 × F × L

d ]3 =

V 2

2 g×[1.5+ 4 ×0.009 × 4

0.1 ]3 = V

2

2 g×2.94

V = 4.40 m/sec

Now using continuity equation,

A1×V 1 ¿ A2×V 2 = A3× V 3......

AV × g = A1×V 1

A = cross section area of pipe

π d2

4 × 4.4 × g = π d2

4 × V 1

d2 ×4.4 × g = d2 V 1

(0.1 )2× 4.4 × g

(0.4 )2 = V 1

V 1 = 2.475 m/sec

Now consider the velocity of flow through each hostel,

Q = AV

A = QV

44

π d2 = QV

d ¿√ QπV

d = diameter of pipe, in mm

Calculating the diameter of the pipe for all the hostels

The diameter of the pipe is calculated by using the discharge equation which

is area times the velocity where area is determined which is then used to compute the

diameter as studied in CE0305 Fluid mechanics.

1. Paari

Qdesigned = 3.294 ×10−1m3/sec

Q = AV

Where,

Q = Discharge, m3/sec

V = Velocity, m/sec

A = Area, m2

3.294 × 10−1 = π d2× 2.475

3.2942.475

× 10−1 = π d2

d = 206 mm

Hence, the diameter of the pipe is 206 mm.

2. Kaari


Q = AV

3.341 × 10−1 = π d2× 2.475

3.34172.475

× 10−1 = π d2

d = 207 mm


3. Oori


Q = AV

45

3.3890 × 10−1 = π d2× 2.475

3.38902.475

× 10−1 = π d2

d = 208 mm


4. Adyaman

Qdesigned = 3.4×10−1m3/sec

3.4 × 10−1 = π d2× 2.475

3.42.475

× 10−1 = π d2

d = 209 mm


5. NRI


Q = AV

1.6311 × 10−1 = π d2× 2.475

1,63112.475

× 10−1 = π d2

d = 145 mm


6. Agasthiyar


Q = AV

1.066 × 10−1 = π d2× 2.475

1.0662.475

× 10−1 = π d2

d = 117 mm


7. Sannasi

Qdesigned = 1.6311 ×10−1 m3/sec

8. Blocks in Sannasi

I - Q Idesigned = 0.252 ×10−1 m3/sec

46

d = √ 0.2527.773

d = 60 mm

II - Q IIdesigned = 0.252 ×10−1 m3/sec

d = √ 0.2527.773

d = 60 mm

III - Q IIIdesigned = 0.252×10−1 m3/sec

d =√ 0.2527.773

d = 60 mm

IV - Q IVdesigned = 0.252 ×10−1 m3/sec

d = √ 0.2527.773

d = 60 mm

Hence, the diameter of the pipes connecting sannasi blocks are 60 mm.

9. Sannasi mess


Q = AV

7.407 × 10−1 = π d2× 2.475

7.4072.475

× 10−1 = π d2

d = 100 mm


GIRLS HOSTEL

10. A-block


Q = AV

3.377 × 10−1 = π d2× 2.475

3.3772.475

× 10−1 = π d2

d = 208 mm

47


11. B - block

Qdesigned = 3.2027×10−1 m3/sec

Q = AV

3.202 × 10−1 = π d2× 2.475

3.2022.475

× 10−1 = π d2

d = 203 mm


12. C - block


Q = AV

3.435 × 10−1 = π d2× 2.475

3.4352.475

× 10−1 = π d2

d = 211 mm


13. D - block


Q = AV

3.298 × 10−1 = π d2× 2.475

3.2982.475

× 10−1 = π d2

d = 206 mm


14. Mess


Q = AV

7.490 × 10−1 = π d2× 2.475

7.4902.475

× 10−1 = π d2

d = 100 mm

48


15. Line A

Qdesigned = 0.02855m3/sec

Q = AV

0.0285 × 10−1 = π d2× 2.475

0.02852.475

× 10−1 = π d2

d = 606 mm


16. Line B


Q = AV

1.751 × 10−1 = π d2× 2.475

1.7512.475

× 10−1 = π d2

d = 150 mm


4.2 SEWER CONSTRUCTION

In sewer construction work, two operations are of special importance,

namely, excavation of trenches, and laying of sewer pipes in trenches and tunnels.

Most of the trench work involves open cut excavation; and in urban areas it includes.

Removing pavement

Removal of the material from the ground, and its separation, its classification

where necessary, and its final disposal.

Sheeting and bracing the sides of the trench

Removal of water (if any) from the trench

Protection of other structures, both underground and on the surface,

whose foundations may be affected

Backfilling

Replacement of the pavement.

49

The most common type of sewer construction practice involves the use of

open trenches and prefabricated pipes. However, larger sewer systems, and unusual

situations may require tunnelling, jacking of pipes through the soil, or cast-in-situ

concrete sewers.

On all excavation work, safety precautions for the protection of life and

property are essential; and measures to avoid too great inconveniences to the public

are desirable. Such measures and precautions include the erection and maintenance

of signs (to forewarn public), barricades, bridges and detours; placing and

maintenance of lights both for illumination and also as danger signals; provision of

watchmen to exclude unauthorized persons, particularly children from trespassing on

the work; and such other precautions as local conditions may dictate. Table 4.1

shows the designed slope and the pipe diameter determined for various hostels (Ref.

7).

Table 4.1 Tabulation of the calculated pipe diameterHostel Q

(m3/sec)Pipe diameter

(mm)Slope 1

inStandard pipe(mm)

Length(m)

Paari 0.329 206 175 230 7.85

Kaari 0.334 207 175 230 6.61

Oori 0.338 208 175 230 5.24

Adhiyaman 0.34 209 175 230 4

NRI 0.163 145 170 150 2.99

Agastiyar 0.106 117 170 150 4

Sannasi I 0.025 60 57 100 4.22

II 0.025 60 57 100 4.71

III 0.025 60 57 100 4.98

IV 0.025 60 57 100 5.65

Sannasi

mess 0.74 100 57 100 9.59

A 0.337 208 175 230 5.74

B 0.32 203 175 230 6.56

C 0.34 211 175 230 9.19

D 0.32 206 175 230 11.88

Main sewer 2.855 606 1000 650 522.69

50

Sub main

sewer 0.175 150 170 150 229.35

4.3 LAYING OF PIPE SEWERS

In laying sewers, the centre of each manhole shall be marked by a peg. Two

wooden posts 100 mm 100 mm 1800 mm high shall be fixed on either side at nearly

equal distance from the peg or sufficiently clear of all intended excavation. The sight

rail when fixed on these posts shall cross the centre of manhole. The sight rails made

from 250 mm wide 40 mm thick wooden planks and screwed with the top edge

against the level marks shall be fixed at distances more than 30 m apart along the

sewer alignment. The centre line of the sewer shall be marked on the sight rail. These

vertical posts and the sight rails shall be perfectly square and planed smooth on all

sides and edges. The sight rails shall be painted half white and half black alternately

on both the sides and the tee heads and cross pieces of the boning rods shall be

painted black. When the sewers converging to a manhole come in at various levels

there shall be a rail fixed for every different level.

The boning rods with cross section 75 mm 50 mm of various lengths shall be

prepared from wood. Each length shall be a certain number of meters and shall have

a fixed tee head and fixed intermediate cross pieces, each about 300 mm long. The

top edge of the cross pieces shall be fixed at a distance below the top edge equal to,

the outside diameter of the pipe, the thickness of the concrete bedding or the bottom

of excavation, as the case may be. The boning staff shall be marked on both sides to

indicate its full length, The posts and the sight rails shall in no case be removed until

the trench are excavated, the pipes are laid, jointed and the filling is started.

When large sewer lines are to be laid or where sloped trench walls result in top-

of-trench widths too great for practical use of sight rails or where soils are unstable,

stakes set in the trench bottom itself on the sewer line, as rough grade for the sewer is

completed, would serve the purpose as recommended by IRC: SP: 42-1994 (Ref. 12).

4.3.1 Depth of flow

51

The sewer shall not run full as otherwise the pressure will rise or fall below

atmospheric pressure also from consideration of ventilation sewer should not be

design to run full in case of circular sewer the manning’s formula reveals that,

The velocity at 0.8 depth of flow is 1.14 times the discharge at full depth of

flow.

The discharge at 0.8 depth of flow is 0.98 times the discharge at full depth of

flow.

According to maximum depth of flow in design shall limited to 0.8 of the

diameter at ultimate peak flow in order to facilitate the calculation easily the

hydraulic properties at various depth of flow are compiled in the Table 4.2,

Table 4.2 Peak flow to facilitate the hydraulic properties

d/D v/V q/Q

1 1 1

0.9 1.24 1.066

0.8 1.14 0.968

0.7 1.12 0.838

0.6 1.072 0.671

0.5 1 0.5

0.4 0.902 0.337

0.3 0.776 0.106

0.2 0.615 0.008

0.1 0.401 0.021

Storm water drainage design,

Q = 3.7 m3/sec

There is natural slope towards (west to east) and the most economical design

parameters are taken into account to avoid the economical constraints.

Open channel is provided for storm water drainage whose dimensions are

given below in the Figure 4.2 as recommended by IS: 2527: 1984 (Ref. 11).

52

Fig. 4.2 Most economical open channel

Where,

b = width of channel

d = depth of flow

A = b×d (4.1)

Wetted perimeter (p),

p = b+d+d

= b+2d (4.2)

From equation (4.1)

b = Ad

Substituting value of b in equation (4.2)

p = b+2d

p = Ad

+2d

Differentiate equation with respect to d,

dpd (d )

= 0

-A

d2+2 = 0

A = 2d2

A = b×d

b×d = 2d2

b = 2d

Now hydraulic mean depth (m),

53

m = Ad

= b × db+2d

= 2 d × d2 d+2 d

m = d2

Q = 3.7 m3/sec

Bed slope (i) is 1 in 1000,

i = 1

1000

C = 1n

× (m)1/6

Where,

n = manning’s coefficient

C = chezy’s constant

m = hydraulic mean depth

n = 0.015

C = 1n

×( d2)

1 /6

Q = AC√mi (as studied in CE0206 Hydraulics)

3.7 = 2d2× 10.015

( d2)

1/6√ 11000

×√ d2

1.390 = d2.66

d = 1.131 m

then,

b = 2d

b = 2.262

54

Fig. 4.3 Dimensions of open channel

Hence the dimensions of the rectangular open channel are shown in Figure

4.3. To deliver the water into Rainwater collecting trench, the length and slope of the

trench is shown in the Table 4.3 as recommended by IS: 2527: 1984 (Ref. 11).

Table 4.3 Slope and length of the open channel

Channel Slope Length

(m)

Level (m)

AB 1/1000 228.63 A = -1.131

BC 1/1000 99.35 B = -1.364


CD 1/1000 223.64 C = -1.466

DE 1/1000 14.58 D = -1.597

EF 1/1000 144.35 E = -1.611

FG 1/1000 216.33 F = -1.846

G = -2.107

4.4 TRENCH DESIGN

In a buried sewer stresses are induced by external loads and also by internal

pressure in case of pressure main as recommended by IS: 1742: 1983 (Ref. 9).

Load due to back fill,

W = cwB2

where,

W = Load on pipe

w = Weight of soil

55

B = Width of trench

c = Dimensions coefficient that measure the effect of

A) Ratio of height of fill to width of trench.

B) Shearing force between interior and adjacent earth portion

C) Direction and amount of relative settlement

There are three classification of construction condition

Embankment condition

Trench condition

Tunnel condition

4.4.1 Trench condition

Generally sewers are laid in ditches or trenches by excavation in natural or

undisturbed soil and then covered by refilling the trench to the original ground level

as studied in CE0306 Foundation Engineering.

4.4.2 Load Producing Forces

The vertical dead load to which a conduit is subjected under trench conditions

is the resultant of two major forces. The first component is the weight of the prism of

soil within the trench and above the top of the pipe and the second is due to the

friction or shearing forces generated between the prism of soil in the trench and the

sides of the trench produced by settlement of backfill. The resultant load on the

horizontal plane at the top of the pipe within the trench is equal to the weight of the

backfill minus these upward shearing forces as shown in Figure 4.4 as recommended

by IS: 1742: 1983 (Ref. 9).

4.4.3 Load calculation

Load of pipe shown in Figure 4.4,

W c = CdWBd2

where,

Wc = Load on the pipe in kg per linear meter

w = Unit weight of backfill soil in kg/m3

56

Bd = Width of trench at the top of the pipe in m

Cd = Load coefficient

Fig 4.4 Free body diagram of the sewer

In order to calculate the loads applied by the pipe, the dead load of the

material in excavation above the concrete bedding is determined which is shown in

the Table 4.4.

Table 4.4 Weight for 650mm diameter pipe

Materials Weight

(kg/m2)

Dry Sand 1600

Ordinary (Damp Sand) 1,840

Wet Sand 1920

Wet Sand 1920

Saturated Clay 2080

Saturated Top Soil 1840

Sand and Damp Soil 1600

Saturated top soil (w) = 1840 kg/m2

Maximum of (Cd ) = 0.461 for ordinary sand and

57

HBd

= 0.5 m

4.4.4 Type of bedding

Bedding factor = desined load × factor of safetyT h ree edgebearing strengt h

= 11.98

64 × 1.5

= 0.3

The bedding dimension criterion for the excavation trench after laying the

pipe lines of various diameter is shown in the Figure 4.5 as recommended by IS:

1742: 1983 (Ref. 9),

Fig 4.5 The bedding dimensions

Class B bedding having a shaped bottom of compacted granular bedding with

carefully backfill as shown in the Figure 4.6 as recommended by IS: 1742: 1983

(Ref. 9),

Fig 4.6 The class B bedding

For safe condition it is necessary to keep width of trench less than the

diameter of pipe,

58

For 650 mm diameter pipe as shown in Figure 4.7,

Bd < 2 Bc

Bd < 2 ×0.650

Bd < 1.3

So assume it as Bd = 1.2

Now,

Load on pipe = 0.469 ×1840 ×1.22

= 11.98 kN/m

W c = 1.98 kN /m≤ 64 kN /m

Hence, safe.

Fig 4.7 The bedding dimensions for 650 mm diameter pipe

For pipe diameter 150 mm as shown in Figure 4.8,

Load on pipe = 0.469 ×1840 × Bd2

Bd < 2 Bc

Bd < 2 ×0.150

Bd < 0.2

W c = 0.461 ×1840 ×0.22

W c = 0.3 kN /m

Hence the load will be very much less and (W c<64 kN /m)

So provide the least trench dimensions for Bedding grade ‘B’

59


For 230 mm diameter pipe as shown in Figure 4.9,

Q = 230 mm

= 0.230 m

Load on pipe = Cd ×W × Bd2

W c = 0.469 ×1840 × Bd2

Bd < 2 Bc

Bd < 2 ×0.23

Bd < 0.45

H = 0.225 m

W c = 0.461 ×1840 ×0.452

W c = 1.68 kN /m

Hence here load is very less and depth ¿1 m

So provide the least possible trench dimension for bedding grade ‘B’ as

recommended by IS: 1742: 1983 (Ref. 9).

60


4.5 PIPE DIMENSIONS

Gladding, McBean is a specialty manufacturer of Vitrified Clay Pipe products

which are used by contractors and agencies throughout the world. Our state-of-the-

art manufacturing processes and technology produces a ceramic product which has

great strength, high density and water tight jointing. Vitrified Clay Pipe is the most

inert of all sanitary sewer pipe materials. It does not have gradual reduction in

strength over time as with resin type products. Chemical resistance likewise does not

deteriorate. Vitrified Clay Pipe is the only pipe which offers both a design and

service life exceeding 100 years.

Hence according to the brochure provided by the manufacturer, the

dimensions of the standard pipe (spigot), bends (mitered pipe) and tees are given

below respectively (Ref. 8).

4.5.1 Spigot

A spigot is a tubular section or hollow cylinder, usually but not necessarily of

circular cross-section, used mainly to convey substances which can flow liquids and

gases (fluids), slurries, powders, masses of small solids. It can also be used for

structural applications; hollow pipe is far stiffer per unit weight than solid members.

The dimensions of the spigot are given in feet and inches since the manual

used as a reference followed the same unit convention (as shown in Table 4.5). The

computations made in the project were based on SI units of meter and centimeters in

order to avoid proximity of calculations. The calculations based on the parameters

are shown in the Figure 4.10 (Ref. 8).

Fig 4.10 Spigot

Table 4.5 Spigot dimensions as per manual

61

Pipes L D1 D2 D3 D4 D5 T1 T2

a 1', 2', 6' 8" 10.02" 11.49" 13.09" 2.31" .98" 0.78"

b 1', 2', 6' 8" 10.02" 11.49" 13.09" 2.31" .98" 0.78"

c 1', 2', 6' 8" 10.02" 11.49" 13.09" 2.31" .98" 0.78"

d 1', 2', 6' 8" 10.02" 11.49" 13.09" 2.31" .98" 0.78"

e 1', 2', 6' 6" 7.87" 9.05" 10.43" 2.33" .87" 0.67"

f 1', 2', 6' 6" 7.87" 9.05" 10.43" 2.33" .87" 0.67"

g 1', 2', 4' 4" 5.3125" 6.5" 7.625" 1.5" .68" .5"

h 1', 2', 4' 4" 5.3125" 6.5" 7.625" 1.5" .68" .5"

i 1', 2', 4' 4" 5.3125" 6.5" 7.625" 1.5" .68" .5"

j 1', 2', 4' 4" 5.3125" 6.5" 7.625" 1.5" .68" .5"

k 1', 2', 4' 4" 5.3125" 6.5" 7.625" 1.5" .68" .5"

l 1', 2', 6' 6" 7.87" 9.05" 10.43" 2.33" .87" 0.67"


m 1', 2', 6' 6" 7.87" 9.05" 10.43" 2.33" .87" 0.67"

n 1', 2', 6' 6" 7.87" 9.05" 10.43" 2.33" .87" 0.67"

o 1', 2', 6' 6" 7.87" 9.05" 10.43" 2.33" .87" 0.67"

Line A 1', 2', 6' 24" 28.85" 30.78" 34.06" 3.67" 2.99" 1.71"

Line B 1', 2', 6' 6" 7.87" 9.05" 10.43" 2.33" .87" 0.67"

4.5.2 Bends

Pipe bending is the umbrella term for metal forming processes used to

permanently form pipes or tubing. One has to differentiate between form bound and

freeform-bending procedures, as well as between heat supported and cold forming

procedures.

The dimensions of the bend are given in feet and inches since the manual

used as a reference followed the same unit convention (as shown in Table 4.6). The




62

Mitered 1/4 or 90° Bend

Fig 4.11 90° Bend

Table 4.6 Bends dimensions as per manual

Bends A D E G I J K H

b1 6-1/4" 6" 4" 7-1/2" 8" 8" 12" 9-1/4"

b2 6-1/4" 6" 4" 7-1/2" 8" 8" 12" 9-1/4

b3 18" 24" 6" 30" 18" 24-3/4" 39-1/4" 24-1/2"

b4 18" 24" 6" 30" 18" 24-3/4" 39-1/4" 24-1/2"

4.5.3 Tees

A tee is used in pipe plumbing systems to connect straight pipe or tubing

sections, to adapt to different sizes or shapes, and for other purposes, such as

regulating or measuring fluid flow.

The dimensions of the tee are given in feet and inches since the manual used

as a reference followed the same unit convention (as shown in Table 4.7). The




63

Fig 4.12 Tees

Table 4.7 Tee dimensions as per manual

T-Joint D&D2 D3 A B

t1 24" 15" 14-1/8" 18-5/8"

t2 24" 15" 14-1/8" 18-5/8"

t3 24" 15" 14-1/8" 18-5/8"

t4 24" 15" 14-1/8" 18-5/8"

t5 6" 4" 6-1/16" 6-5/16"

t6 6" 4" 6-1/16" 6-5/16"

t7 6" 4" 6-1/16" 6-5/16"

t8 6" 4" 6-1/16" 6-5/16"

t9 24" 15" 14-1/8" 18-5/8"

t10 24" 15" 14-1/8" 18-5/8"

t11 24" 15" 14-1/8" 18-5/8"

t12 24" 15" 14-1/8" 18-5/8"

t13 24" 15" 14-1/8" 18-5/8"

c1 24" 15" 14-1/8" 18-5/8"

64

The nomenclature used in the previous tables for various pipes, bends and

tees are shown in Figure 14.4.

4.6 MANHOLES

4.6.1 Junction Manholes

A manhole should be built at every junction of two or more sewers, and the

curved portions of the inverts of tributary sewers should be formed within the

manhole. The soffit of the smaller sewer at a junction should be not lower than that

of the larger, in order to avoid the surcharging of the former when the latter is

running full, and the hydraulic design usually assumes such a condition.

The gradient of the smaller sewer may be steepened from the previous

manhole sufficiently to reduce the difference of invert level at the point of junction to

a convenient amount as recommended by IS 4111 (Part-1): 1986 (Ref. 13).

4.6.2 Spacing of Manholes

Manholes should be built at every change of alignment, gradient or diameter,

at the head of all sewers and branches, at every junction of two or more sewers. On

sewers which are to be cleaned manually which cannot be entered for cleaning or

inspection the maximum distance between manholes should be 30 m as

recommended by IS 4111 (Part-1): 1986 (Ref. 13).

4.6.3 Sizes of Manholes

The circular manholes may be constructed as alternative to rectangular and

arch type manholes. Circular manholes are much stronger than rectangular and arch

type manholes and thus these are preferred over rectangular (ordinary) as well as

arch type of manholes. The circular manholes can be provided for all depths starting

from 0.9 m. Circular manholes are straight down in lower portion and slanting in top

portion so as to narrow down the top opening equal to internal diameter of manhole

cover. Depending upon the depth of manhole, the diameter of manhole changes. The

internal diameter of circular manholes may be kept as following for varying depths.

For depths above 0.90 m and up to 1.65 m, 900 mm diameter


65



4.6.4 Construction

Excavation - The manhole shall be excavated true to dimensions and levels as

shown on the plan. The excavation of deep manholes shall be accompanied with

safety measures like timbering, staging, etc. In areas where necessary, appropriate

measures for dewatering should be made.

Bed Concrete - The manhole shall be built on a bed of concrete 1: 4 : 8 ( 1

cement: 4 coarse sand: 8 graded stone aggregate 40 mm nominal size ) unless it is

otherwise required by the local bodies, etc. Generally the thickness of bed concrete

shall be 225 mm for manholes of depth less than 2.30 m and 300 mm for depths of

2.30m and above, unless otherwise specified on account of specific considerations.

This may, however, be designed to carry safely the weight of walls, cover, the wheel

loads, impact of traffic which are transmitted through cover and shaft walls and also

for water pressure, if any. In case of weak soil, special foundation as suitable shall be

provided. The thickness of wall shall in no case be less than one brick length.

Generally the wall shall be built of one brick length thickness for depth less than 2.25

m. The thickness of wall for depths from 2.25 m to 3.0 m is kept one and half brick

length, for depth from 3.0 to 5.0 m, two brick length; for depths 5.0 to 9.0 m, two and

half brick length and beyond 9.0 m depth it may be 3 brick length as recommended

by IS 4111 (Part-1): 1986 (Ref. 13).

66

Fig 4.13 Typical illustration of circular manhole

Plastering - The walls of manholes shall be plastered both inside and outside

with cement mortar 1:3 (1 cement: 3 coarse sand) and finished smooth with a coat of

neat cement. Typical illustration of the circular manhole used in shown in the Figure

4.13.

4.6.5 Safety measures

In deep manholes enlarged rest chambers should be made at about 6 m

intervals, each provided with a landing platform in the form of a grating

incorporating a hinged trap-door immediately under the ladder.

All manholes on sewers of 1 m diameter and over should be provided with

provision for fixing safety chains (galvanized wrought-iron close link, 6 or 10 mm)

for placing across the mouth of the sewer on the downstream side when men are at

work, and galvanized pipe hand-rail, (nominal 38 mm bore) should be provided on

67

the edges of all benching, platforms, etc, to prevent possibility of a man falling into

the sewer.

If ground conditions are such as to give rise to excessive risk of settlement

and consequential damage to the manhole or sewer a concrete slab shall be provided

at the top of the shaft to receive the cover frame. This should be independent of the

shaft in order to avoid transmitting traffic shocks to the manhole. Any subsidence of

the backfilling on which the slab rests, shall be brought to the required road level

without disturbing or damaging the pipe or the shaft.

No manhole shall be permitted inside a building or in any passage, therein.

In cascades and ramps, hand-rails and chains should be provided for the

safety of workmen as recommended by IS 4111 (Part-1): 1986 (Ref. 13).

4.6.6 Hazards caused by stray voltage in manholes

In urban areas, stray voltage issues have become a significant concern for

utilities. At some places it was electrocuted after stepping on a metal manhole cover.

One solution is the Electrified Cover Safeguard invention, which is an on-site, real-

time stray voltage warning system and other utilities and municipalities in European

countries.

68

Fig 4.14 Pipes, Bends and tees nomenclature

69

4.7 COST ESTIMATION AS PER QUANTITY

The cost estimation as studied in CE0411 Estimation cost and professional

practice, is carried out for individual quantity as per latest pricing records proposed

by PWD where each cost includes transportation of materials, labor charges, various

taxes and construction execution as shown in the Table 4.8 (Ref. 8).

Table 4.8 Cost estimation of underground drainage system

S.No.

Description Nos. Measurement Quantity (m3)

Rates per

meter (rs)

Amount in (Rs)L(m) B(m) D(m)

1. ExcavationI. For 650 mm pipe

diameterII. For 150 mm pipe

diameterIII. For 230 mm pipe

diameterIV. For 100 mm pipe

diameterV. Manhole digging

VI. Stormwater open channel

1

1

1

1

161

573.25

229.38

65.07

23.49

-875

1.2

0.3

0.45

0.2

-2.262

1.1

0.5

0.6

0.425

-1.931

756.69

34.07

17.56

1.99

-3822

39.5

39.5

39.5

39.5

2039.5

29889.25

1359

693.9

78.86

320150969

2. Concrete BeddingI. For 650 mm pipe




diameterV. Concrete lining

for open channel

1

1

1

1

1

573.25

229.38

65.07

23.49

875

1.2

0.3

0.45

0.2

2.262

0.48

0.115

0.17

0.075

0.2

333.63

7.91

5.12

0.35

395

1170

1170

1170

1170

1170

390350

9258.92

6000

412.25

462150

3. Removing earth and refilling

I. For 650 mm pipe diameter

II. For 150 mm pipe diameter

III. For 230 mm pipe diameter

1

1

1

-

-

-

-

-

-

-

-

-

423.06

26.49

12.44

33

33

33

13960.98

874.4

410.52

70

IV. For 100 mm pipe diameter

1 - - - 0.97 33 32.01

4. Breaking of pavement - - - 405.39 26 10540.24

5. Pipeline I. For 650 mm pipe




diameter

314

126

36

5

573.25

229.38

65.07

23.49

-

-

-

-

-

-

-

-

-

-

-

-

390 Rs

130 Rs

280 Rs

85 Rs

122460

16380

10080

425

6. ManholeI. Cement concrete

with plinth in cement mortar (1:4:8)

II. Cement concrete (1:2:4) with brick work

III. Cement plaster (1:3)

IV. Reinforced cement concrete (1:2:4)

V. Mild steel reinforcements for slab

VI. Rectangular cover 455x610 mm with frame

VII. Carriage of C.I. cover & frame

VIII. Painting of C.I. cover & frame with coal tar

16

16

16

16

16

16

16

16

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.43

0.34

0.16

0.25

10.57 kg

1 unit

6.76

6.76

3593.3

3508.25

4514.05

173.10

56.7 Rs/kg

1415

1.49

1.49

24721.92

19084.88

11555.96

692.4

9589.10

22640

161.16

161.16

71

IV.8 ABSTRACT ESTIMATION

The abstract estimate as studied in CE0411 Estimation cost and professional

practice, is the total cost of all the items used with combined quantity and rates. This

gives the total cost of an item to be purchased as shown in the Table 4.9 (Ref. 8).

Table 4.9 The abstract estimation of the underground drainage system

S.no. Quantity (m3) Description Rate

(Rs)

Per Amount

(Rs)

1 810.31 Excavation 39.5 m3 32022

2 3470.01 Concrete bedding 1170 m3 406020

3 462.96 Removing earth

and refilling

33 m3 1577.91

4 16 Digging manhole

holes

20 hole 320

5 405.394 Breaking of

pavement

26 m2 10540.24

6 481 Pipeline Depends

on

diameter

No. 149345

7 16 Manhole Varying unit 88606.58

Total

=

688431.73

Add 1% of electrical work = Rs. 6,884.31

Add 1% of Sanitary settings = Rs. 6,884.31

Add 5% of lump sum and miscellaneous = Rs. 34,421.5

TOTAL COST = Rs. 7,36,621.93

72

CHAPTER 5

CONCLUSION

5.1 CONCLUSION

Drainage and sewerage system have always been part of essential

infrastructure in modern cities and town. In SRM university separate systems are

provided for collection and disposal of sewage and storm water.

Over the past ten years, population in SRM University has increase significantly.

This has led to an increase in water consumption and a consequential increase in

quantity of waste water to be handled.

The project study concluded that rapid developments in the study area have

resulted in higher runoff and some existing drainage systems are inadequate in

respect to flood protection capacities. Consequently, severe flooding and overflowing

occurs in these low-lying areas during heavy rainfall. The environmental constraints

were eradicated by undergoing the construction in winters to increase efficiency and

optimum anti-corrosive measures are undertaken. Use high performance concrete is

adopted in order to resolve the sustainability constraint. Most economical design

methods are done using economically efficient products in order to avoid economical

constraints. The proposed drainage improvements to be carried out under the project

involve the construction of the underground drainage system and an open channel at

SRM university hostel.

V.2 FUTURE SCOPE OF THE PROJECT

The future scope of the project includes the design of underground drainage

system in the main campus and fuses it with the latter drainage system to enhance the

arsenal of the project.

73

REFERENCE

1. http://en.wikipedia.org/wiki/Drainage_system, retrieved on September 12, 2013 at 9.45am.

2. http://www.imd.gov.in/section/hydro/distrainfall/webrain/tamilnadu/kanchipuram.txt, retrieved on September 15, 2013 at 7.15pm.

3. G.s. bajwa, 2010, public health engineering, storm water drainage, pg356

4. Jack Q. Zhao, 1998, P.Eng., Durability and Performance of Gravity Pipes

5. Linsley r.k., m.a. Kohler and j.h.l. Paulhus, 1975, hydrology for engineers, 2nd edition, pg112

6. S.k. garg, 2008, environmental engineering, vol 2, sewage treatment, pg 102, 104

7. http://www.gladdingmcbean.com/docs/PipeBrochure.pdf, retrieved on January 11, 2014 at 3.25pm.

8. S.k. garg, 2006, environmental engineering, vol 1, water suppy engineering

9. IS 1742 – 1983, Code Of Practice For Building Drainage (Second Revision)

10. IS 1172 – 1993, Code Of Basic Requirements For Water Supply, Drainage And Sanitation (Fourth Revision)

11. IS 2527 – 1984, Code Of Practice For Fixing Rainwater Gutters And Downpipes For Roof Drainage (First Revision)

12. IRC:SP:42 - 1994, Guidelines On Road Drainage13. IS 4111 – 1986, Code Of Practice For Ancillary Structures In Sewerage

System: Part I Manholes (First Revision)

74

http://www.gladdingmcbean.com/docs/PipeBrochure.pdf

http://www.imd.gov/

http://en.wikipedia.org/wiki/Drainage_system

1st phase analysis

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