Graduation Semester and Year

Fall 2024

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Civil Engineering

Department

Civil Engineering

First Advisor

Nur Yazdani

Second Advisor

Vistasp Karbhari

Third Advisor

Antonio Balderrama Garcia Mendez

Fourth Advisor

Chen Kan

Abstract

Vehicular crashes onto bridge piers are one of the primary causes of bridge failures. The current bridge design approach against vehicle impact involves either providing structural resistance to the pier or impact load redirection. When the design choice is to provide structural resistance, the columns shall be designed to withstand the impact load. If the choice is to redirect the collision load, a barrier shall be constructed. However, in the existing bridge piers, where barrier construction is impossible due to site constraints, other measures of protecting the piers shall be necessary to ensure acceptable damage control. One such measure of pier protection is the application of Fiber Reinforced Polymers (FRP) at the pier’s extremities.

The American Association of State Highway and Transportation Officials (AASHTO, 2020) has proposed risk-based guidelines to carry out risk calculation by calculating the annual frequency of bridge collapse, AF­BC, for un-retrofitted bridge piers. However, no such guideline exists for FRP retrofitted piers. Hence, this study was performed to assess the failure risk depending on the performance of impacted FRP retrofitted piers. The approach involved calculating the piers' demand (D) and capacity (C) during such impact events. Based on the target performance of both critical and typical bridges, stochastic D/C ratios were obtained and were used to calculate the probability of failure (Pf) of piers in respective bridge types. Similarly, the current practice of selecting the best pier retrofitting option entails conducting a Benefit-Cost Analysis (BCA) without considering its performance. The current study proposed a Relative Index (RI), which is the sum of the Annualized Benefit-Cost Ratio (BCRA) and the scaled AF­BC, which defines the performance of the retrofitted pier. Finally, a decision tree was proposed to assist design engineers in selecting the best retrofitting options for both new construction and existing piers against vehicular collision.

Keywords

Bridge, Vehicle Impact, CFRP, KFRP, Retrofitting, Decision Tool, Risk Analysis, Probabilistic Analysis, Pier Protection, Cost-Benefit Analysis.

Disciplines

Civil Engineering

License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Available for download on Saturday, January 02, 2027

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