引言众所周知,对不同类型的结构体系在地震作用下的性能曾做过许多工作,以研究建筑物和其他地面上的结构物的设计准则。然而,对城市地区的生活来说,至关重要的一个主要结构系统(例如生命线系统),还没有引起足够的重视。天然气和石油管道、自来水和污水管道、煤气和石油储 INTRODUCTION It is well known that much work has been done on the performance of different types of structural systems under earthquake action in order to study the design criteria for structures on buildings and other floors. However, a vital structural system, such as the Lifeline System, which is of crucial importance to the lives of urban areas, has yet to receive enough attention. Gas and oil pipelines, water and sewer pipes, gas and oil storage