DECISION SUPPORT TOOLS FOR ECONOMIC RESOURCES ALLOCATION IN SEISMIC RETROFITTING OF BUILDINGS

Abstract

A vast number of existing masonry and RC buildings in Italy is located in medium-to-high level seismic hazard regions and they are particularly vulnerable to earthquakes. Although strengthening interventions are urgent, resources are limited and seismic retrofitting the whole existing building stock is not practical. Thus, it is necessary to optimize the allocation of resources for strengthening interventions, taking into account the cost constrains and those variables connected to the repair and indirect costs, such as number of inhabitants, the priority and the size of the building, the vulnerability level. This work addresses the decision issue related to the optimal budget allocation for proactive strengthening actions on buildings located in seismic areas and reactive repair after an earthquake. The goal is to minimize the number of uninhabitable buildings considering their capacity in terms of residents. A two-stage stochastic model with recursions is used to perform the analyses, assuming to have a maximum cumulative budget which can be used for proactive (strengthening) and/or reactive (reconstruction) actions. The solution of this stochastic problem is compared with the solution of the problem where the budget is used only for reactive actions. The outcomes are presented and discussed with reference to a real case of a small town in Sicily.