Mitigation Analyses for the Selection of Effective Seismic Retrofit Strategies at a Territorial Scale

Abstract

Recent developments of viable and low-cost retrofit solutions within a multi-level retrofit approach, suggest the possibility to implement “standardised” solutions at a urban or territorial scale. However, due to the limited funds available, alternative strategies should be considered in order to define the most effective action plan able to minimise the overall risk. Such mitigation analyses, although not yet codified, are expected to become a fundamental decision making tool for the allocation of funds by local authorities, as is already happening overseas. In this paper the efficiency of different structural mitigation strategies will be investigated within the framework of a seismic risk analysis approach. Alternative mitigation strategies will be examined by combining: 1) alternative retrofit solutions based on different techniques and targeting various performance objectives; 2) spatial distributions of the intervention for targeted typologies. The effectiveness of the aforementioned alternative mitigation strategies will be assessed with reference to a case study area using different mitigation analysis methods, based on a single- or multi-criteria approach within either a deterministic or a stochastic evaluation.