クロス・インパクト法によるライフライン系の地震時相互連関のモデル化

Abstract

A probabilistic model to evaluate the seismic risk of urban lifeline networksystems is developed with emphasis on the interactive aspects of lifeline earthquakedisaster. First, the outline of interaction-related problems in lifeline earthquakedisaster is compiled in a comprehensive table. Next, with the understanding thatfunctional dependence among lifelines causes a significant interaction in the event ofearthquake, focus is placed on two network systems model in the light of functionaldependence of a lifeline system on the other. The probability of system malfunctioncaused by damage interaction in addition to the damage to the system itself isassessed. Through this, system interaction is quantified on a probabilistic basis as asingle parameter, in terms of the "cross impact factor". Besides, incorporating ahazard curve method, the effectiveness of back-up facilities has been evaluated. Themethod of fault tree analysis is conveniently used in the process of probabilisticcalculation. An illustrative numerical example is presented.