Evaluation of Critical and Essential Concrete Highway Bridges in a Moderate Seismic Hazard

Abstract

The task of this thesis is to determine if the response of critical and essential bridges designed using the AASHTO LRFD Bridge Design Specifications would meet performance requirements when subjected to the moderate seismic hazard present in the state of Alabama. The design procedures for these concrete superstructure bridges involve a displacement-based design found in the AASHTO Guide Specifications for LRFD Seismic Bridge Design. Displacement-based design procedures in bridges can provide an economical and efficient design. However, a caveat to using the displacement-based design procedures of the Guide Specifications relates to its inapplicability for critical or essential bridges. This thesis will provide an analysis of designed bridge behavior in the state, and determine if this behavior is acceptable for bridges classified as critical or essential. Recommendations and conclusions relating to design will also be provided for bridges subject to Alabama’s moderate hazard.