This document summarizes a student project on designing components of a pre-stressed concrete girder bridge. The project included introducing bridges and their design, pre-stressing methods and design according to AASHTO provisions. A design example was completed along with structural drawings. Spreadsheets were developed to facilitate design. The bridge was modeled in SAP and structural configurations were analyzed. Designs were conducted for deck slab, barriers, girders and tendons.

1. Bridges are important to everyone. But they
are not seen or understood in the same way
by everyone, which is what makes their
study so fascinating. Everyone is looking at
the same bridge, but it produces different
emotions and visual images in each.
“A structure that span an opening or gap, 6
m or larger, such as: a water way (River,
canal etc.), a valley, another roadway or
railway lines is called a bridge. Further the
term bridge is used for the structures built
to continue traffic load, pedestrian traffic or
utility lines across a gap in a roadway.”
(Ref. AASHTO 1.2)
In this project, attempt has been made to
elaborate procedures for designing of
various components of pre-stressed
concrete girder bridge. This includes
general introduction of bridges and their
design description. This project also deals
with the details of pre-stressing methods
and their design procedure according to
AASHTO provisions. A complete design
example along with structural drawings of
slab and girders has also been
accomplished. Spread sheets have been
developed to facilitate the design procedure.
These sheets are capable of designing
girders with desired section properties and
also are capable of selecting AASHTO
specified girders.
To understand the structural
configurations bridge has been modeled on
SAP bridge wizard.
Structural drawing
Conclusions
References
◊ AASHTO LRFD Design Specifications for Bridges
◊ Edward G. Nawy, Reinforced Concrete 5th Ed., Pearson Prentice Hall, New Jersey
◊ Nilson, Aurther H. Design of prestressed concrete 2nd Edition, John Wiley & Sons, New Yark
◊ Z.A Siddiqi, Concrete Structures, 2rd Ed. Part I&II, Help Civil Engineering Publisher, Lahore, 2012.
☞Project Advisor:
Engr. Muhammad Mazhar Saleem
Assistant Professor (Department of Civil Engineering)
☞Project Group Leader:
Hafiz Ahmed Waqas (2011-Civil-179)
☞Project Group Members:
Muhammad Usman (2011-Civil-161)
Syed M. Imran Shah (2011-Civil-174)
Muhammad Abdullah (2011-Civil-176)
Department of Civil Engineering
University of Engineering and Technology, Lahore
Preparation of Structural Drawings
Deck Slab, Side Barrier, Girders and Tendon Profiles
Modeling using SAP Bridge Wizard
Understanding the structural configuration
Development of Spread Sheets for Design
Design of Girders/AASHTO Girders Selection
Design
Deck Slab, Exterior and Interior Girders
Analysis of Bridge Components
Methods for Analysis, Load Calculations
Literature Review
History, Types, and site selection for Bridges
Design Process
Modeling on Bridge Wizard
Bridge Components
Abstract
Introduction
Design Results
Deck Slab and Side Barrier
Tendon Profile Calculations
 Design for both of exterior and interior girders was performed,
and heavier girder was provided, so that a symmetrical deck is
obtained.
 AASHTO HL-93 design traffic loading has been used for analysis
and design of the bridge. But later on design adequacy should be
checked according to Pakistan code of practice class A, class B
loading for highway bridges.
 Specified AASHTO highway girders are available for specific span
and loading conditions. However, in case these girders are
inadequate, then special girders may also be designed and
manufactured. The developed spread sheets in this project also
address the above said purpose.
Project Participants