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Doctoral Examination: Seismic behaviour of concrete wall bridge pier reinforced with shape memory alloy
December 15, 2022 at 12:00 pm - 4:00 pm
Nursafarina Ahmad, supervised by Dr. Shahria Alam, will defend their dissertation titled “Seismic behaviour of concrete wall bridge pier reinforced with shape memory alloy” in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Civil Engineering.
An abstract for Nursafarina’s dissertation is included below.
Examinations are open to all members of the campus community as well as the general public.
If you would like to attend this virtual examination please contact the supervisor at email@example.com to receive a zoom link.
Reinforced concrete bridge (RC) was designed with high ductility and built-in high seismic areas to prevent collapse from a seismic event. During Hashin-Hawaii seismic event in 1995, it was observed that bridge wall pier performance in a weak direction is still far from the acceptable level. The bridge wall pier suffered from high residual drift making the bridge unserviceable. The performance-based seismic design (PBSD) is a comprehensive method that limits the local and global deformation of the bridge to the acceptable design load level. The objective of PBSD can be accomplished by implementing Shape Memory Alloy (SMA) as a reinforcement bar to enhance seismic performance in concrete bridge piers. This research aims to investigate the seismic behaviour in weak directions for wall bridge pier reinforced with shape memory alloy. To provide comprehensive information, this study started with a parametric study to evaluate the influence of geometry and material properties using fractional factorial analysis. The test results were explored to evaluate the influence of concrete strength, steel yield strength, SMA yield strength, longitudinal and transverse reinforcement ratio, aspect ratio, and skew angle. In addition, the aspect ratio result was calibrated with experimental work. The seismic performance of a 1/3 scaled wall pier reinforced with SMA was investigated experimentally using lateral cyclic loading in the weak direction. In addition, the test result was compared to the conventional reinforced concrete wall in terms of hysteretic curves, maximum and residual drift, displacement recovery capacity, and energy dissipation. The quantitative damage states associated with different performance levels (cracking, yielding, spalling, and crushing) for RC wall pier reinforced with three different types of SMAs were developed using Incremental Dynamic Analysis (IDA). Based on an extensive numerical study using IDA, the effect of compressive strength, aspect ratio, and longitudinal and transverse reinforcement ratio was evaluated for three different types of SMAs. Finally, vulnerability curves are established for three different RC-SMA wall piers using maximum and residual drift as engineering demand parameters. It was discovered that the RC-SMA wall pier has a low probability of damage and minimizes residual drift, which significantly contributes to the life cycle cost benefit.