International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 08 | Aug-2016
www.irjet.net
e-ISSN: 2395 -0056 p-ISSN: 2395-0072
COMPARISON ON BEHAVIOUR OF BOX GIRDER BRIDGES WITH DIFFERENT SHAPE
Karthika Santhosh1, Prof. P Asha Varma2 1PG
Student, Department of Civil Engineering, NSS College of Engineering, Palakkad, Kerala, India
2Professor,
Department of Civil Engineering, NSS College of Engineering, Palakkad, Kerala, India
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Abstract - The present study focus on the behaviour of
A box girder is particularly well suited for use in
box Girder Bridge with different shape by keeping the
curved bridge systems due to its high torsional rigidity
span length constant. The bridge is modelled and
resulting in better transverse load distribution. High
analysed in SAP Bridge 2000 version 14. The cross
torsional rigidity enables box girders to effectively
section of the superstructure of the box girder bridge is
resist the torsional deformations encountered in
in form of a single cell box. The curvature of the bridges
curved thin-walled beams. Analysis and design of box-
varies only in horizontal direction. All the models are
girder bridges are very complex due to its three
subjected to dead load and super imposed dead load,
dimensional behaviours consisting of torsion, and
prestressed load and moving load of IRC class A tracked
bending in longitudinal and transverse directions.
vehicle. Static analyses under different loading
Analysis and design of the box girder can be divided
conditions are performed. From this study it is concluded
into two parts i.e. longitudinal analysis and transverse
that the trapezoidal section is superior to circular and
analysis. In each analysis method, the three-
rectangular section.
dimensional bridge structure is modelled by means of
Key Words: Box girder bridge, Radius of curvature, Torsion, Longitudinal bending stress, SAP Bridge.
girder
relationship between its components. The accuracy of analysis depends on the assumptions taken for bridge
1. INTRODUCTION
A box
assumptions in the geometry, materials and the
structure.
bridge is
a bridge in
which
the
2) PROBLEM DEFINITION
main beams comprise girders in the shape of a hollow of
In this study mainly three types of box girder are used
or
for analysis namely Trapezoidal, Rectangular and
a composite of steel and reinforced concrete. The box is
Circular. The details of the crossection are shown in
typically rectangular, trapezoidal or circular in cross-
figure 1 and table 1.
box.
The box
either prestressed
girder normally
comprises
concrete, structural
steel,
section. Box girder bridges are commonly used for highway flyovers and for modern elevated structures of light rail transport.
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