2>C£ 23/4^
STUDY ON STRUCTURAL ASPECTS OF UNDERPASSES IN 
SOUTHERN TRANSPORT DEVELOPMENT PROJECT
The thesis submitted to the Department of Civil Engineering of the University of
Moratuwa in partial fulfillment of the requirements for the Degree of Master of
Engineering in Structural Engineering Design.
LIBRARY"
!l*IVfrRSIYV Of MORATUWA, SR! LAK.v<
V.QRATUWA
By
V.G. Liyanagamage
Research Supervised By
Prof. M. T. R. Jayasingha
University of Moratu>va
93912
DEPARTMENT OF CIVIL ENGINEERING 
UNIVERSITY OF MORATUWA 
SRI LANKA.
Semptember 2009
93 9/z
(■'
:•I - 4 &
6 >4- i)
93312
Abstract
ABSTRACT
The Colombo-Matara express highway also known as the Southern Lanka Express 
Highways or simply the Southern Expressway is a highway currently under construction 
in Sri Lanka. The 126 km long highway will link the Sri Lankan Capital Colombo with 
Matara, a major city in the Southern Province of the Island. Construction of the highway 
began in 2006 and it is expected to be completed in 2010 at the cost of $600 million. 
When completed, it will reduce the time taken to travel from Colombo to Matara to one 
and a half hours from the current four hours.
It is known fact that the Southern Highway and other subways linked with are normally 
supported by a wide range of different structures which require careful thought in 
selecting a suitable one for each location. In fact, these structures form a vital part of 
transport infrastructure and the smooth running of the network as designed. Even though, 
this study has been narrow down only to underpasses from the vide range of structures 
being used. Therefore, in this research work, it is mainly focused on to the underpasses 
such as metal and concrete underpasses used in and its significant impact on the cost 
initiatives, suitability and the environmental impacts and etc.
The technology used for the metal underpasses on this project is new to Sri Lanka. 
Traditionally in Sri Lanka, pre cast concrete structures are the preferred option, however, 
in this project, metal underpasses has also been used. The introduction of new technology 
requires knowledge of their structural behavior, particularly when used in combination 
with other materials, and their long-term durability. Over the last years, many structures 
have started to show signs of degradation and deterioration as a result of the high chlorate 
content in the air in southern Sri Lanka and some kind of crack failures due to bad 
workmanship as well as lack of adequate supervision. All these issues has been discussed 
and concluded in this report in a precise manner based on physical observation and on 
literature survey.
i
Abstract
Finally, this research concludes that the use of concrete box underpasses in the southern 
highway is mostly substantiated with country like Sri Lanka due to its inherent 
characteristics and with the economy and the durability concerns.
In fact, this report is a part of a post contract analysis which describes important facts that 
had to be emphasized in selection of the structure underpasses for Southern highway 
project and concluded which type of underpasses would have been used with the great 
economic impact to Sri Lanka.
ii
Acknowledgement
Acknowledgement
I would like to make this opportunity to forward my sincere thanks to the project 
supervisor, Prof. M.T.R. Jayasingha who helped me to make this project a success by 
giving advice and looking in to the problems encountered. His guidance and constructive 
criticism helped me o execute the project successfully.
I wish to thank the Vice Chancellor, Dean of the Faculty of Engineering and the Head, 
Department of Civil Engineering for allowing me to use the facilities available at the 
University of Moratuwa.
I am grateful to the RDA for the leave granted to me to follow the postgraduate degree
course.
I wish to thank to Dr. I.R.A.W. Weerasekara, course coordinator and Dr(Mrs) M.T.P. 
Hettiarachchi, the research coordinator of the project for the encouragement given to me 
in completing this study, and all the lecturers of the postgraduate course on Structural 
Engineering Design who helped me to enhanced my knowledge.
Special thanks go to Mr. L.G. Sirisena, Mrs. V.B. Panditha, my loving parents, for the 
support given for my education and learn to be confident throughout the career. I also 
would like to thank my husband for giving valuable support and encouragement to 
complete the study during the period.
Finally, I gratefully acknowledge everybody who helped me in numerous way in 
completing my research study.
V.G. Liyanagamage. 
August 2009.
iii
Declaration
DECLARATION
I, V.G. Liyanagamage, hereby declare that the content of the thesis is the output of the 
original research work carried out at the Department of Civil Engineering, University of 
Moratuwa. Whenever others’ work is included in this thesis, it is appropriately 
acknowledged as a reference.
V V^CXCja.
...Qk/.!flJ. ....
Signature
Name of the Student
Date
Signature
Name of the Supervisor
Date
iv
Contents
Pages
Abstract..................
Acknowledgement 
Declaration............
1
m
IV
Contents.........
List of Figures 
List of Tables.
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IX
1Chapter 1..........
1.0 Introduction 1
11.1 General....................................................
1.2 Main Objectives..................................... .
1.3 Methodology...........................................
1.4 Main Findings.........................................
1.5 Arrangement of the Report.....................
Chapter 2.......................................................
2.0 Literature Review..................................
2.1 Applications of Corrugated Steel Products
2.2 Description of Corrugations.....................
2.3 Structural Properties of Conduit Wall......
2.4 Pipe Seams.............................................
2.5. Minimum Cover Requirements..............
2.6. Normal Bedding.....................................
2.7. Camber..................................................
2.8. Selection of Structural Backfill...............
2.9. Vertical Deflection.................................
2.10. End Protection......................................
2.11 Failures in Metal structures....................
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172.11.1. Buckling of the conduit wall..... ......................
2.11.2. Bolt hole tears............................................. .
2.11.3. Bearing failure at longitudinal seams..............
2.11.4. Excessive deformation of conduit cross section
2.11.5. Collapse of the structure.................................
2.11.6 Remedial measures.........................................
Chapter 3................................................................. .
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193.0 FIELD SURVEY
193.1 Introduction.............................................................
3.2 Method and work Procedure.....................................
3.2.1 Metal Structures................................................
3.2.1.1 Filling and Excavation....................................
3.2.1.2. Foundation Preparation..................................
3.2.1.3. Camber at Installation....................................
3.2.1.4. Erection of Structures....................................
3.2.1.5. Backfilling.....................................................
3.2.1.6 Shape Control.................................................
3.2.1.7 End Treatment................................................
3.2.2 Box Culvert......................................................
3.2.2.1 Filling and Excavation...................................
3.2.2.2. Construction of Box Culverts........................
3.3. Failures in Metal Underpasses.................................
3.4 Summary.................................................................
Chapter 4........................................................................
4.0 Analysis of Metal Structure & Results................
4.1 Introduction.............................................................
4.2 Description of Loads on the Metal Structure.............
4.2.1 Dead Load.......................................................
4.2.2. Live Load HB Loading...................................
4.3. Design Calculation as per AASHTO (For HPA 74N)
4.3.1 Description of the Proposed Structure................
4.3.2 Outline Drawing of the Proposed Structure.........
4.3.3. Design Pressure................................................
Chapter 5........................................................................
Analysis of Box Culvert, Results & Design..............
5.1 Introduction.............................................................
5.2 Load Cases........................................................
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Vvi
325.3 Loads on the Box Culvert
325.3.1 Loads due to soil..............................
5.3.2 Live Loads......................................
5.3.3. Loads on the top slab.......................
5.3.4. Loads on the side walls...................
5.3.5. Loads on the bottom slab.................
5.3.6 Horizontal Live load due to traction... 
5.3.7. Hydrostatic Pressure.......................
5.4 Modeling of Box Culvert........................
5.4.1 Load Calculation..............................
5.4.1.1 Dead Load Calculation..................
5.4.1.2. Live load calculation....................
5.4.1.3. Super Imposed Dead Load............
5.4.1.4. Reaction from Soil Calculation......
5.4.1.5 Lateral earth pressure calculation ....
5.4.1.6. Traction force...............................
5.4.1.7. Hydrostatic Pressure....................
5.5 Concrete Outline Drawing of Box Culvert
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435.6. SAP2000 model of the Box Culvert
445.7 Load Combinations
445.8 Deformed Shape for Load Case 4.3...
5.9 Results from the SAP2000 Modeling
Chapter 6........................................
6.0 COST ANALYSIS....................
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476.1 Introduction..............................
6.2 Cost Estimating Process............
6.3 Cost Analysis of Metal Structure
6.4. Cost Analysis of Box Culvert.... 
6.5 Cost Saving..............................
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51Chapter 7...............................................................
7.0 CONCLUSIONS AND RECOMMENDATION 51
52REFERENCES
53APPENDIX -A
vii
List of Figures
Page
2Figure 1.1 : View of a Metal Structure.............................................
Figure 1.2 : View of a Box Culvert..................................................
Figure 1.3 : Typical Details of Metal Structures..............................
Figure 2.1 : (a) Longitudinal Stiffeners (b) Transverse Stiffeners
Figure 2.2: Types of Corrugations available....................................
Figure 2.3: Sectional Properties of Selected Corrugation...............
Figure 2.4 : Typical Flat Bedding.....................................................
Figure 2.5 : Typical Vee Shaped Bedding........................................
Figure 2.6 : Cambered pipe...............................................................
Figure 2.7 : Typical Vertical Deflection..........................................
Figure 3.1 : Husker walls are cracked..............................................
Figure 3.2 : Weeds comes through the plates of Metal Structure...
Figure 3.3 : Plates are Corroded......................................................
Figure 4.1 : Concrete Outline of the HPA74N................................
Figure 5.1 : Loads on the Box Culvert.............................................
Figure 5.2 : HB Vehicle Wheel Arrangement..................................
Figure 5.3 : Concrete Outline of Box Culvert..................................
Figure 5.4 : Model of Box Culvert..................................................
Figure 5.5 : Deformed shape of Mode 1..........................................
Figure 5.6 : Deformed shape for Mode 2........................................
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List of Tables
Page
12Table 2.1 : Ultimate Seam Strength for MP152 Corrugated Structures
Table 4.1 : Description of the Proposed Structure..............................
Table 5.1 : Results from the SAP2000 Modeling...............................
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ix