The large losses occurred in the past due to earthquakes, even in highly developed countries, as well as the ensuing prolonged inactivity of the stricken societies, imparted momentum to research into regional seismic impact and community resilience to earthquakes. Need for comprehensive and consistent modeling is apparent, and this work presents a contribution in this direction. The extension of a recently developed civil infrastructure simulation framework to the evaluation of resilience, as well as the introduction of a new infrastructure network-based resilience metric represent the novelties of the article and allow one to explore the effect that sources of uncertainty and key vulnerability factors have on the probability distribution of resilience

The basic function of a gas distribution system, essentially composed of buried pipelines, reduction stations, and demand nodes, is to deliver gas from sources to end users. The objective of the article is to discuss the evaluation of seismic risk of gas networks in compliance with the performance-based earthquake engineering framework adapted to spatially distributed systems. In particular, three issues are addressed: (1) spatial seismic hazard characterization in terms of ground shaking and permanent ground deformation; (2) analysis of system's vulnerability via fragility curves; (3) seismic performance evaluation via computer-aided simulation. As an application, the seismic risk analysis of L'Aquila (central Italy) gas distribution network, a 621-km mid- and low-pressure pipeline system was considered. The analyses were performed with reference to the mid-pressure part of the network, through an object-oriented software, specific for risk assessment of lifelines, developed by the authors. Results in terms of connectivity-based performance indicators are presented and discussed, along with a performance disaggregation analysis carried out to evaluate the contribution of the components of the system to the risk.

Electric power networks are spatially distributed systems, subject to different magnitude and recurrence of earthquakes, that play a fundamental role in the well-being and safety of communities. Therefore, identification of critical components is of paramount importance in retrofit prioritization. This article presents a comparison of five seismic performance assessment models (M1 to M5) of increasing complexity. The first two models (M1 and M2) approach the problem from a connectivity perspective, whereas the last three (M3 to M5) consider also power flow analysis. To illustrate the utility of the five models, the well-known IEEE-118 test case, assumed to be located in the central United States, is considered. Performances of the five models are compared using both system-level and component-level measures. Spearman rank correlation ρ is computed between results of each model. Highest ρ values, at both system- and component-level, are obtained, as expected, between M1 and M2, and within models M3 to M5. The ρ values between component-level measures are relatively high across all models, indicating that simpler ones (M1 and M2) are appropriate for vulnerability assessment and retrofit prioritization. The complex flow-based models (M3 to M5) are suitable if actual performance of the systems is desired, as it is the case when the power network is considered within a larger set of interconnected infrastructural systems. © 2014 Computer-Aided Civil and Infrastructure Engineering

A life cycle framework for a new integrated classification system for buildings and the identification of renovation strategies that lead to an optimal balance between reduction of seismic vulnerability and increase of energy efficiency, considering both economic losses and environmental impacts, is discussed through a parametric application to an exemplificative case-study building. Such framework accounts for the economic and environmental contributions of initial construction, operational energy consumption, earthquake-induced damage repair activities, retrofitting interventions, and demolition. One-off and annual monetary expenses and environmental impacts through the building life cycle are suggested as meaningful performance metrics to develop an integrated classification system for buildings and to identify the optimal renovation strategy leading to a combined reduction of economic and environmental impacts, depending on the climatic conditions and the seismic hazard at the site of interest. The illustrative application of the framework to an existing school building is then carried out, investigating alternative retrofitting solutions, including either sole structural retrofitting options or sole energy refurbishments, as well as integrated strategies that target both objectives, with a view to demonstrate its practicality and to explore its ensuing results. The influence of seismic hazard and climatic conditions is quantitatively investigated, by assuming the building to be located into different geographic locations.