Seismic Performance of Corroded RC Bridge Piers
: A Large-Scale Shaking Table Study

  • Xiao Ge

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)

Abstract

This thesis presents a set of shaking table benchmark tests on six large scale RC bridge piers with/without corrosion damage. Three well-confined specimens are tested with three spectrally matched ground motion records (near-field without pulse, near-field pulse-like and far-field) to investigate the non-stationary properties of the ground motion. To examine the effects of confinement and corrosion, three low-confined specimens are tested by the same ground motion (i.e. far-field). Two of the low-confined columns are corroded by the accelerated corroding procedure. The mass loss ratios of the steel reinforcement in the two specimens are 51% and 65%. Four rounds of the main tests with different scale factors (25%, 300%, 500% and another 300% as aftershock) of the ground motion PGA are conducted. Before the first round of the main test and after each round of the main test, low-amplitude white-noise tests are conducted to explore the fundamental frequency variation before/after the test. A spatial investigation is carried out on the corroded specimens to investigate the effects of corrosion distribution. With the experimental data, a rapid damage assessment method based on time-frequency analysis (i.e. Wigner-Ville distribution and Hilbert transform) is proposed. This non-parametric method only relies on input and output acceleration time-histories due to the easy acquisition of acceleration in situ. The effectiveness of this method is benchmarked by the moving linear regression of hysteretic loops and white-noise tests. A system identification strategy on the extended Bouc-Wen model with unknown parameters is proposed. Genetic algorithm is used in this process. A numerical model of the RC column is developed. The performance of the model in terms of hysteresis and energy dissipation modelling is benchmarked by the experimental data. To demonstrate the application of the proposed numerical model in design process, incremental dynamic analysis (IDA) on uncorroded columns is carried out. The results compare the performance of engineering demand parameters (i.e. drift and energy dissipation) in sequential earthquake events.
Date of Award12 May 2020
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorNicholas A Alexander (Supervisor) & Mehdi Kashani (Supervisor)

Keywords

  • Shaking table test
  • Corroded RC columns
  • Near field
  • Far field
  • Time-frequency analysis
  • Wigner-Ville distribution
  • Hilbert transform
  • OpenSees
  • Bouc-Wen model

Cite this

Seismic Performance of Corroded RC Bridge Piers: A Large-Scale Shaking Table Study
Ge, X. (Author). 12 May 2020

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)