Risk Assessment and Maintenance of Existing Trunk Lines with a New Subsidiary System under Seismic and Deteriorating Environments

摘要

This paper describes a seismic risk assessment for existing trunk lines which are to be annually expanded by the subsystems consisting of a subsidiary pipeline network and the shutoff valve. The maintenance activities range from daily patrols to large-scale retrofit, while taking the deterioration effect into consideration. The discussion focuses on the probability of failure for the overall system, for various combinations of the safety level in the control valve and the pipeline network.