Comparative Analysis and Design of Box Girder Bridge Sub-structure With Two Di

International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN

0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 4, Issue 5, July – August (2013), © IAEME

134

COMPARATIVE ANALYSIS AND DESIGN OF BOX GIRDER BRIDGE SUB-

STRUCTURE WITH TWO DIFFERENT CODES

Patil Yashavant S.1, Prof. Shinde Sangita B.

2

1P.G. Student, Dept. of Structural Engineering, Jawaharlal Nehru Engineering College,

Aurangabad-431003, Maharashtra. India 2Asst. Professor, Dept. of Structural Engineering, Jawaharlal Nehru Engineering College,

Aurangabad-431003. Maharashtra, India

ABSTRACT

The design of a highway bridge is critically dependent on standards and criteria. Naturally,

the importance of highway bridges in a modern transportation system would imply a set of rigorous

design specifications to ensure the safety, quality and overall cost of the project. This paper discusses

the comparative analysis of two standards namely AASHTO and IRC followed in construction of

bridge superstructures subjected to load of heavy vehicles. To find out optimized Design, variety of

checks and exercise are performed that are presented in this paper. As a result of this exercise it is

found that results of bending moment and stress for self-weight and superimposed weight are same,

but those are different for the moving load consideration, this is due to the fact that IRC codes gives

design for the heavy loading compared to the AASHTO codes.

The results showed the IRC codes are costly because of the number of reinforcement bars in the pile

cap and piles is more than those with AASHTO code with the same dimensions. Displacement

Analysis is carried out using the ANSYS Software of finite elements base modeling, it shows that as

the intensity of displacement increases chances of settlement also increases.

Keywords- Concrete Bridge Pile, Pile Cap, Nodal Displacement, Reinforcement, ANSYS Model

I. INTRODUCTION

For design of Mega Bridge superstructures there are many codes used around the world and

many countries have their own code depending on the natural conditions and the surrounding

environmental factors, such as the effect of earthquakes and heavy snowfall, etc. In the United States,

Bridge Engineers use the code of AASHTO “American Association of State Highway and

Transportation Officials”; this code can be adopted for design of the highway bridges with special

requirements. Similarly, Indian bridge engineers refer to the IRC (Indian Road Congress) standard to

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ISSN 0976 - 6480 (Print) ISSN 0976 - 6499 (Online) Volume 4, Issue 5, July – August 2013, pp. 134-139 © IAEME: www.iaeme.com/ijaret.asp Journal Impact Factor (2013): 5.8376 (Calculated by GISI) www.jifactor.com

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135

do the design. However The AASHTO Standard Specification is adopted by many countries as the

generally accepted code for bridge designs.

While designing project two different codes might result in different design as well as cost

implications. Therefore to choose the most appropriate one, it’s important to do comparative analysis

of codes and their resulting design. To prove this hypothesis in this study following two codes are

chosen.

1) AASHTO-LRFD Bridge Design Specifications

2) IRC and IS codes Design Specification

The Two codes will be used to do the analysis of Box Girder. The similarities and differences,

advantages and disadvantages of each code will be investigated.

II. DESIGN DATA

The manual design for the bridge foundation was done according to the data and the

information available from the project site. The parameters used to design the bridge foundation of

Box Girder Bridge are as follows:

1.The length of the girder is 30 m, the weight is 3563.21 kN. Figure 1 shows the cross section of box

girder.

2.Superimposed dead load (the dead loads above the beam) is 18.5 kN/m.

Figure 1 Cross section of Box girder

3.Concrete pier column is 2 m in diameter, and lateral width is 4 m. The drop panel

diameter is 4 m in both sides with top hat thickness of 20 cm. The total height of pier

with the drop panel is 16.7 m. All dimensions and detailed information are shown in Figure 2.

4.Live load from the superstructure is shown in Table 1.

Code Load

IRC 2267.25KN

AASHTO 1084.28KN

Table 1 Live Load Reaction Comparision

The values of live loads in Table 1 have been taken from previous analysis of box girder in Midas

Civil Software. as we observe reaction due to live load is more in IRC than AASHTO.

Following types of loadings are adopted for the analysis of two lane box girder,

� As per IRC

Vehicle Load: - Class AA and Class A

Dynamic Allowance: - 33%

� As per AASTHO

Vehicle Load: - HL-93TDM, HL-93TRK

Dynamic Allowance: - 33%



136

III. RESULT AND DISCUSSION

As shown in Table 2 that the design with the two codes is different in some parts of the bridge

and similar in the other, the number of steel bars in the IRC codes is more than that of AASHTO

code. That is because, the IRC codes take higher factor of safety when calculating the amount of

reinforcement required, but at the same time, this design can be deemed economically because it

provides the same dimensions of the foundation. Figure 2 show values of the reinforcement area of

bending for pile cap and piles respectively, it can be seen that the reinforcement area of IRC code is

higher than the other codes. Figure 3 shows the full details of pile foundation reinforcements.

Code Pile Cap Pile

IRC 32mm� bar at 150mm

spacing

10mm� stirrups

at 200mm spacing

29mm� bar of 12 Nos.

AASHTO 32mm� bar at 200mm

spacing

10mm� stirrups

at 300mm spacing

29mm� bar of 8 Nos.

Table 2 Reinforcement comparison

Figure 2 Reinforcement Area comparison

As we observer the pile detailing, lateral reinforcement is same for both the piles because diameter of

piles are same. Figure 4 shows the full details of pile cap reinforcements. The 1144KN and 1528KN

load acting on pair of piles, as we go through the reinforcement detail in IRC design required steel is

more than AASHTO.

IV. ANALYSIS WITH ANSYS PROGRAM FOR FINITE ELEMENT MODEL

Another analysis, using the numerical analysis of the ANSYS program of finite

elements to ascertain the values calculated previously manually and found out the design

suitable to withstand the external loads, by calculating the value of vertical displacement and

other parameters relying on the same dimensions calculated from the design and the same

loads applied.

AASHTO IRC

pile reinfocment 5094.401 7314.366

pile cap reinforcment 3893.72 4771

0

1000

2000

3000

4000

5000

6000

7000

8000

Re

info

em

en

t A

rea

(m

m2)



137

Figure 3 Reinforcement details of Pile for AASHTO and IRC code

Figure 4 Reinforcement details of Pile Cap for AASHTO and IRC code



138

Figure 5 Vertical displacement result for AASHTO code in ANSYS

The load applied in the model is the same as that used for the previous design and analysis

which is about 3431.57KN according to the AASHTO code and 4580KN according to IRC code. The

results of the numerical analysis are shown in Figures 10 to 13. The maximum value for

displacement equal to -18 mm for AASHTO and -24 mm for IRC, respectively, the minus sign refers

the direction of the displacement to down, as we observed the nodal analysis, IRC design shows

more displacement and moment values than AASHTO.

Figure 6 Vertical displacement result for IRC code in ANSYS



139

V. CONCLUSION

This paper presents comparative analysis of Bridge sub-structure that would help designer

while considering different factors based on code at the beginning of the project. We also showed

how to use ANSYS for the analysis of box girder. It gives result based on finite element modeling,

Displacement shown by nodes are specified in above figures, Box girder shows better resistance to

the torsion of superstructure.

The bearing capacity of the single pile calculated by the AASHTO code is only 75%

of that calculated by the IRC Code which provide high safety to provide the suitable number of

piles by the first Code. Results of bending moment and stress for self-weight and superimposed

weight are same, but those are different for the moving load consideration, because IRC codes gives

design for the heavy loading compared to the AASHTO codes. Area of steel required for AASHTO

is less compared to IRC. Finally based on this comparative study it’s clear that AASHTO code is

more economical than IRC.

REFERENCES

1. IRC: 6- 2000 “Standard specifications and code of practice for road bridges” Indian road

congress.

2. IRC: 18 – 2000 “Design criteria for prestressed concrete road bridges (post – tensioned

concrete)” Indian roads congress.

3. IS: 1343 – 1980 “Code of practice for prestressed concrete” Indian standard.

4. IRC: 21 –2000 “Standard specification and code of practice for road bridges (Plain and

Reinforced)” Indian road congress.

5. AASHTO (2007). “AASHTO-LRFD Bridge Design Specifications”

6. Hussein Yousif Aziz and Jianlin Ma, “Design and analysis of bridge foundation with

different codes”, Journal of Civil Engineering and Construction Technology Vol. 2(5), pp.

101-118, May 2011.

7. Priyanka Bhivgade, “Analysis and design of prestressed concrete box Girder Bridge” Civil

engineering portal.

8. Young-Ha Park and Chan-Min Park, “Development of Long Span Prestressed Concrete I

Girder Bridge by Optimal Design” expressway transportation research institute 08-06.

9. V.N. H EGGADE, R.K. MEHTA & R. P RAKASH,” Design and Construction of Pre-

Tensioned Sutlej Bridge in Punjab” 143-158.

10. Hussein Yousif Aziz and Jianlin Ma,“Experimental and Theoretical Static Analysis of High-

Speed Railway” The Open Construction and Building Technology Journal,2012, 6, 17-31

11. RICHARD A. MILLER “AASHTO LRFD Bridge Design Specifications of Prestressed

Concrete” AASHTO-LRFD Specification, 4th Edition

12. S. Rana & R.Ahsan, “Design of prestressed concrete I-girder bridge superstructure using

optimization algorithm”, IABSE-JSCE Joint Conference on Advances in Bridge Engineering-

II, August 8-10, 2010.

13. Text Book of “Design of Bridges”, By N. Krishna Raju, Fourth Edition OXFORD & IBH

PUBLISHING CO. PVT. LTD.

14. Text Book of “Prestressed Concrete a fundamental Approach”, By Edward G. Nawy, Fifth

Edition.

15. Patil Yashavant S. and Prof.Shinde Sangita B., “Comparative Analysis of Box Girder Bridge

with Two Different Codes”, International Journal of Civil Engineering & Technology

(IJCIET), Volume 4, Issue 3, 2013, pp. 111 - 120, ISSN Print: 0976 – 6308, ISSN Online:

0976 – 6316.

Documents

Comparative Analysis and Design of Box Girder Bridge Sub-structure With Two Di