Evaluating alternative approaches for the seismic design of structures

Abstract

The current design approach recommended by seismic codes is often based on the use of uniform-hazard response spectra, reduced to account for inelastic structural behaviour. This approach has some strong limitations that have been highlighted in many studies, including not allowing a direct control of the seismic risk and losses. This study aims at quantifying the levels of safety and the costs associated with this design approach, and to investigate alternative design approaches that have been developed in the last decades. In particular, a risk-targeting approach and a minimum-cost approach are considered. The first one, allowed by US codes, aims at designing structures with the same risk of collapse throughout regions of different seismicity. The second one aims to minimize the sum of the initial construction cost and the cost of expected losses due to future earthquakes. The comparison of the three approaches is performed by considering, as an example structure, a fourstorey reinforced concrete frame building located in different areas in Europe, and by looking at the implications in terms of achieved safety levels, initial costs, and future losses. The study's results provide useful information on how the design criteria and the different hazard levels throughout Europe affect the cost and safety levels of seismic design.

Seismic risk management through insurance and its sensitivity to uncertainty in the hazard model

“…This section presents a brief summary of previous research by the authors (Gkimprixis et al 2020), to demonstrate the risk and loss assessment methodology that is the basis of the work presented here. The study concerns a 4-storey 3-bay RC building (Fig.…”

“…Focusing on the risk mitigation mechanism, the previous work (Gkimprixis et al 2020) investigated three alternative seismic design approaches. According to the uniform hazard approach, which is the basis of most design regulations, the design acceleration is chosen as the value that has a predefined probability of exceedance in a given time period (e.g.…”

“…This section presents an application of earthquake insurance modelling for the 4-storey 3-bay RC building which was designed (using the uniform-hazard approach) and analysed in Gkimprixis et al (2020) (see Sect. 2).…”

“…This article presents an investigation of how the seismic hazard, and its uncertainty can affect risk management plans. For this purpose, the four-storey reinforced-concrete (RC) building of a previous article by the same authors of this work is considered (Gkimprixis et al 2020), together with different seismic hazard scenarios in Europe. Section 2 illustrates a brief overview of the design and risk and loss assessment of the building, whereas Sect.…”

Risk-targeted Maps for Spain

“…In most recent studies such as Gkimprixis, Tubaldi, and Douglas (2020) and Crowley, Silva, and Martins (2018), the building-speci c fragility functions have been implemented in risk-targeting analysis to avoid gaining overestimated values of collapse risk speci cally for low hazard regions. Considering the variability of P c |gm, and β in risk-targeted analysis, we decided to develop random variables distribution functions.…”