To study about Box Girder Bridge

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2. Department of Civil Engineering
Analysis and Design of a Prestressed
Concrete Box Girder Bridge
Seminar
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3. Outline of Presentation
Abstract
Introduction
Objectives of the study
Scopes of the study
Design Data
Material Properties of Proposed Bridge
Analytical results (due to dead load, moving load and load combinations)
Checking of maximum deflection
Calculation of slab design
Discussion and Conclusion
Recommendation
References 3

4. Abstract
 In this study, prestressed concrete box girder bridge is analyzed and
designed by using SAP 2000 software.
 The total length of bridge (200 ft) with three continuous spans is analyzed
and designed successfully. Side spans are 60 ft for each and main span is 80
ft. The total width is 29 ft for truck way and 3.5 ft each for the two
sidewalks width.
 Truck load generation for highway is applied to every 10 ft apart along the
roadway.
 7 in thick truck way slab, 6 in thick sidewalk slab and 3 in wearing surface
for roadway are used. The main reinforcement for truck way slab is No.5
bar with spacing 5 inches and distribution steel is No.5 with spacing 7 inch.
The main reinforcement for sidewalk slab is No.4 bar spacing 8 inch and
distribution steel is No.3 with spacing 8 inch.
 Box girder sections are chosen as exterior girder vertical in this study.
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5. Introduction
 Bridges are defined as structures which provide a passage over
a gap without closing the way beneath, which carries railroad,
highway and footpath, pipeline traffic over an obstacle such as
river, another highway, or a railroad.
 Bridges are the most common infrastructures in the nation’s
highway system.
 Bridges have occupied very great importance in highway
improvement because the natural conditions that the
topography is steep and many rivers flow in our country.
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6. (continued)
 There are many types of bridge, among them prestressed
concrete bridge is considered with box girder in this study.
 Box girder bridges: The single (or multiple) main girder
consists of a box beam fabricated from steel plates or formed
from concrete, which resists not only bending and shear but
also torsion effectively.
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7. (continued)
Figure.1. Various types of box girder cross-section 7

8. Objectives of the study
 to know the preliminary considerations of prestressed concrete
bridge,
 to obtain better understanding of design concept of prestressed
concrete bridge,
 to analyze and design the prestressed concrete bridge with design
specification for highway bridge published by AASHTO
specification,
 to get the suitable design of prestressed concrete box girder bridge,
and
 to understand the computer-aided analysis and design.
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9. Scopes of the study
 the required data of this bridge are collected from the Ministry of
Construction,
 the proposed bridge is 200 ft span length with two lanes prestressed
concrete bridge,
 load consideration is based on AASHTO specification,
 structural elements are designed according to ACI 318-02,
 concrete box girder is used in girder section, and
 SAP 2000 software is applied in this study.
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10. Proposed Bridge Model
Figure.2. General Views of Prestressed Concrete Bridge
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