Electronic Theses and Dissertations

Identifier

6390

Date

2018

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Engineering

Committee Chair

Adel Abdelnaby

Committee Member

Adel Abdelnaby

Committee Member

Shahram Pezeshk

Committee Member

Charles Camp

Abstract

Since after every single earthquake, a structure faces a stiffness and strength degradation, it may not be able to withstand subsequent shaking especially when seismic retrofit is not an option due to the short time intervals between the successive earthquakes. Therefore, it is necessary to consider the effects of repeated shaking on the behavior of structures prone to multiple earthquakes. Although many studies have been performed so far, there are some significant deficits which need more attention. Some of the important limitations in most of the recent studies include: (1) the use of ground motion data from uncorrelated events occurring at different locations and times; (2) utilization of simple models that do not contain appropriate damage features; and (3) no proper consideration to the effects of earthquake direction, aftershock polarity, structure irregularity, and the vertical component of the earthquake. The objective of this study is twofold, first to remedy the aforementioned limitations by using a robust finite element model that simulates the degrading behavior of reinforced concrete structures subjected to as-recorded seismic sequences, as opposed to replicate or uncorrelated random earthquakes. Second, to derive fragility relationships for RC structures under different limit states while considering the effects of damage accumulation in structures subjected to multiple-earthquake scenarios. For this purpose, the nonlinear response of different types of reinforced concrete buildings (both regular and irregular in elevation) will be evaluated and the effects of the overlooked parameters in previous research will be investigated. The results presented in this study indicate that earthquake direction (in the irregular building), structure irregularity, and the vertical earthquake component can have a considerable effect on the response of structures subjected to multiple earthquakes. Findings also show that aftershock polarity can significantly change the response of the irregular structure. Based on the results, considering damage from previous events, number of stories, and earthquake region significantly affect fragility curves. Results also indicated that as-recorded seismic sequences do not have a significant effect on period elongation.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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