Seismic vulnerability of lifelines in the greater Lisbon area

Abstract

A study on the seismic vulnerability of the lifeline systems in the greater Lisbon area, in Portugal, is described. The work is part of a major program, an initiative of the Portuguese Authority for Civil Protection, intending to develop a tool for the assessment of seismic impact and emergency planning support. It had as a final goal the development of a simulator for the damage estimation of different lifeline systems, working on a GIS, including highways and railways, water supply systems, electric power supply systems, liquid and gas fuels systems. Previous publications have focused on the analysis methodologies and results regarding both the integrated lifeline system and the individual systems (Azevedo et al. in Seismic impact on lifelines in the great Lisbon area, 13th world conference on earthquake engineering, Vancouver, 2004; Guerreiro and Azevedo in Seismic vulnerability assessment of highways and railways—application to the great Lisbon area, 13th world conference on earthquake engineering, Vancouver, 2004). This paper focuses on some of the main conclusions and shows some of the interdependences between the performances of the several systems. Among some of the analyzed issues, regarding the several systems, are:

• Comparison of the assumed seismic input and its format: magnitude, epicentral distance, peak ground acceleration, peak ground velocity, permanent ground displacement;

• Comparison of output response characterization: malfunction probability, percentage of damaged equipment, probability of different damage states;

• Construction of the fragility curves for the different systems, with the description of the general methodologies and criteria;

• Comparison of the performance of the different systems and main common reasons for malfunctioning; the output of some analyzed scenarios is shown and the discussion on its reliability is analyzed.