Dissertation Defence: Integrated Life Cycle and Performance-Based Design of Bridges Considering Climate Change
August 12 at 8:00 am - 12:00 pm
Alaa Al Hawarneh, supervised by Dr. Shahria Alam, will defend their dissertation titled “Integrated Life Cycle and Performance-Based Design of Bridges Considering Climate Change” in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Civil Engineering.
An abstract for Alaa Al Hawarneh’s dissertation is included below.
Examinations are open to all members of the campus community as well as the general public. Please email shahria.alam@ubc.ca to receive the Zoom link for this exam.
ABSTRACT
The compounding effect of seismicity, exposure to corrosion, and climate change in regions such as North America pose significant challenges for bridge design engineers since the multi-hazard impact on the performance-based design of bridges remains underexplored. This research provided a performance-based assessment and design approach for bridges in multi-hazard environments, aiming to improve their fragility, and minimize their remaining lifecycle cost (LCC).
Initially, a comprehensive screening framework for deficient concrete bridge piers was proposed, incorporating criteria beyond the traditional condition index, such as location, population density, and other socio-economic impacts. An indicator called the Bridge Screening Index (BSI) was proposed to prioritize deficient bridge piers. Subsequently, a probabilistic seismic demand assessment (PSDA) in the form of temporal incremental dynamic analysis (IDA) was employed to formulate predictive expressions for reinforced concrete columns in various environments, including marine atmospheric zones, marine splash zones, and deicing-salt spray regions, and with the use of various climate-change scenarios. Analysis indicated that the future effect of corrosion varies depending on the excitation level of the earthquake. Notably, the average increase in drift values, for the case of (Dicing Salt Spray – Uniform Corrosion – Climate-Change not Considered), if the earthquake intensity is 0.1g (refers to Ln PGA = -2.3), was 6.2% after 60 years from the time of inspection. The step following PSDA is fragility analysis. This study developed novel time-based fragility tools for reinforced concrete bridge columns, accounting for the cyclic enhancement in seismic fragility due to routine maintenance actions. Finally, an optimization model, using mixed-integer linear programming, was employed to minimize the operational LCC while maintaining the fragility of the bridge within a user-defined upper limit for each damage state. Finally, A case study was used to illustrate the proposed approach. With this optimization model, it was possible to decreases the LCC of two existing bridge piers, in two different environments: marine atmospheric and marine splash, by 37.4% and 34.1%, respectively. Overall, the results of this study indicate that reducing the maintenance interval between future activities is beneficial only up to a certain limit, which varies depending on the seismic risk and environmental exposure.
