Date of Award

11-2016

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

First Advisor

Dr. Aman Mwafy

Second Advisor

Dr. Amr Sweedan

Third Advisor

Khaled E Galal

Abstract

The precise definition of performance limit states at both the member and structure levels, considering brittle failure modes, is essential to arrive at reliable earthquake loss estimation systems for reinforced concrete (RC) buildings. A wide range of shear failure prediction approaches that account for the impacts of shear-axial interaction and flexural ductility on shear supply are thus assessed analytically and experimentally in this study, aiming at selecting verified models for the vulnerability assessment of pre-seismic code and code-conforming RC buildings. The shear supply models of both columns and shear walls are implemented in a versatile post-processor to monitor the shear supply-demand response during multistep dynamic simulations. Ten reference structures are adopted to represent pre-code and modern RC buildings in the highly populated and seismically active areas of the UAE, which is selected as a case study to represent medium seismicity regions. The pre-code structures are assessed using a diverse range of far-field and near-source seismic events, while the vulnerability of code-conforming buildings is investigated under the effect of horizontal ground motions only (HGMs) as well as both horizontal and vertical ground motions (HYGMs). Based on the extensive inelastic dynamic response simulations of the pre-code buildings, it is concluded that the influence of shear assessment on the performance limit states is more pronounced on shear wall structures compared with frame buildings, particularly for relatively medium-rise wall structures. For this class of buildings, the impact of shear response on the results obtained from both far-field and near-source earthquake scenarios is observable. For code-conforming structures, the impact of shear assessment on the performance limit states is more observable under the effect of HYGMs, particularly medium-rise wall structures. The results confirmed that the damage probabilities of both pre-seismic code and modern buildings increase with decreasing the building height. Therefore, earthquake scenario-structure-based limit state criteria are selected and used to derive a wide range of fragility relationships for the ten reference buildings using different earthquake scenarios. The results of the analytical study reflected the pressing need for confirmatory testing to provide further insights into the shear response of RC members under cyclic loading and the suitable shear strength models for the vulnerability assessment. Shake table testing is thus conducted for shear vulnerable RC specimen representing the framing system of a substandard building. The specimen is subjected to a far-field earthquake record with four increasing intensity levels. The shake table test results of the specimen are compared with those obtained from dynamic response simulations. It is confirmed from the comprehensive shake table results that the first indication of shear failure is detected in the columns provided with the higher longitudinal reinforcement ratio at eight times the design PGA, which is well predicted by the shear strength approaches adopted in this study. The consistent results obtained from both the shake table testing and dynamic response simulations verify the adopted limit states and confirm the reliability of the developed fragility curves in this study for the seismic loss estimation of the RC building inventory in the UAE.

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