Vulnerability Functions for Seismic Loss Assessment of the Modern Multi-Story Buildings in Dubai.
Abstract
The rapid development in the United Arab Emirates along with the repeated seismic activity confirm the significance of planning for the possible damage that may hit earthquake-prone areas in order to mitigate earthquake losses. The contemporary buildings are the most important when estimating the potential losses from earthquake since they represent concentrated economic and human assets. This study aims at developing vulnerability functions for a wide range of modern building inventory in a highly- populated and earthquake-prone area in the UAE. Ten reference buildings with varying heights from 2 to 100 stories and three different lateral force resisting systems are selected to represent the study area. The reference buildings are completely designed and detailed as per the design provisions and construction practice utilized in the UAE. Detailed fiber-based numerical models are developed for the reference structures and forty natural earthquake records are selected to account for the uncertainty in seismic demands. Over 5,000 inelastic analyses are performed to derive three-dimensional vulnerability functions for the investigated structural systems. It is concluded that, unlike the satisfactory performance of the shear wall and tube in the tube structural systems, the flat slab-columns system is vulnerable to the severe distant earthquakes. It is suggested to decrease the over strength factor and increase the deflection amplification factor by 10% for the low-rise flat slab-columns system. For the shear wall and tube in tube systems, the force reduction factors can be increased by at least 10%, with a possibility of further increase after a thorough assessment of the proposed reduction in seismic loads. It is also proposed to adapt an effective stiffness of 0.5EI, 0.8EI and 1.0EI for the vertical elements of the flat slab-columns, shear wall and tube in tube structural systems, respectively, to arrive at an accurate estimate of the inelastic periods of vibrations. The derived three-dimensional vulnerability relationships in the present study enable the interpolation of results to arrive at the fragilities of a wide range of buildings with different hi=eights and systems. The developed fragility curves are prepared for the direct integration in a comprehensive loss estimation system for the region.