Theses and Dissertations

Date of Award

5-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Civil Engineering

First Advisor

Siang Zhou

Second Advisor

Mohsen Amjadian

Third Advisor

Philip Park

Abstract

Skewed and horizontally curved steel I-girder bridges are commonly designed and constructed to connect existing roadways and navigate obstacles in densely populated areas. However, these bridges can introduce significant challenges to bridge design and analysis, including complex lateral movements and torsional effects. Simplified support representation techniques that are commonly adopted in analysis and design may not accurately capture these effects, which lead to potential misestimations of bridge responses. This research aims to evaluate skewed and curved steel I-girder bridges for complicated loading and support conditions – skewed integral abutment bridges were studied during pre-composite deck placement and horizontally curved bridges were assessed under various thermal loading conditions.

The study on pre-composite loading in skewed steel I-girder integral abutment bridges aims to assess the efficiency of simplified support representations against field-validated models. Six single-span Integral Abutment Bridges (IABs) with varying design parameters were analyzed through extensive numerical parametric analysis using 3D models developed in ABAQUS, as well as in partial 3D and 2D using CSI-Bridge. All models with simplified support underestimated lateral response near girder ends when deep cross-frames were used for IABs with staggered cross-frames. Defining proper restraints over girder bottom flange width to represent realistic anchor bolted connection was found to be critical for skewed IABs deck placement analysis, for bridges with moderate skew and with cross-frame-to-girder-depth ratio that meets AASHTO requirements.

In the thermal loading study of horizontally curved steel I-girder bridges, ABAQUS simulations were conducted for bridges with various support conditions, including guided, elastomeric, integral abutment, and fixed bearings. The bridges were subjected to uniform temperature variations and thermal gradients, including the AASHTO-specified profile and direct sunlight heating of exterior girders. Support conditions were observed to significantly affect the thermal response – fixed bearings led to higher stresses and movements than other supports. Heating of exterior girders due to direct sunlight induced substantial flange lateral bending stress, which could be underestimated if only the AASHTO gradient is considered in design. This illustrates the need for incorporating realistic thermal gradient profiles in bridge analysis and design, especially for bridges in environments prone to direct sunlight heating.

Comments

Copyright 2025 Bikesh Sedhain. https://proquest.com/docview/3240627114

Download

Share

COinS