A Cost–Benefit Analysis Framework for City-Scale Seismic Retrofitting Scheme of Buildings

Abstract

To improve urban seismic resilience, a reasonable seismic retrofitting scheme for buildings is required. Urban cities contain a large number of buildings, making it challenging to precisely assess the seismic retrofitting benefits of each one. This paper proposes a cost–benefit assessment framework that takes into account seismic risk, seismic damage, retrofit costs, economic losses, and cost–benefit analyses for the city-scale seismic retrofitting of buildings. The proposed framework adopts readily available building parameters, including the number of stories, construction year, total height, structural type, floor area, and response spectrum for structural design. It makes use of empirical seismic retrofitting models and a newly developed story-level seismic loss assessment method combining the physical mechanism and empirical loss ratios. For city-scale cost–benefit analysis, the framework can strike a good balance between data accessibility, computational workload, level of result details, and result accuracy. It can adapt nimbly to earthquake-induced indirect losses and budgetary constraints on retrofitting. The analysis of 98,618 buildings in Xi’an city, China, is carried out. The findings indicate that, when potential indirect economic loss ratios of buildings are neglected, the retrofitting benefits of unreinforced masonry and old buildings are the most significant.

Seismic Response of a Tall Reinforced Concrete Frame Structure Subjected to both Horizontal and Vertical Strong Motions

“…The continuous development of urban areas coupled with the ageing of built-stock and the variety of structures built following different design code recommendations caught the attention of decision makers and researchers around the world. While the primary role of the former is to draft resilience plans in case of natural disasters [1], with particular focus on strong earthquakes, the responsibility of the latter may reside into offering accurate information on the behaviour of different types of structural systems in case of a severe earthquake [2]. The first step towards reducing the associated risk, seismic risk in this case, of a natural disaster consists in correctly evaluating the vulnerability of at-risk structures and the possible consequences that may rise after a severe seismic event.…”