Historical aspects of lifeline earthquake engineering

Abstract

This study describes a developing process of lifeline earthquake engineering from historical aspects. Currently various seismic design methods have been furnished for ground shaking and for permanent ground displacement. The seismic design method for ground shaking introduces different travelling wave models in the US and in Japan. As a result, Japanese approach was developed by actively taking into account the slippage effect in order to solve the inelastic response of the pipeline for a severe earthquake. The seismic design method for permanent ground displacement, on the other hand, prepared various numerical modeling and database in the US, while the simplified design formula for ground displacement was furnished in the seismic design guidelines in Japan. The detail design formula for liquefied ground settlement and fault displacement are expressed in this study. Various approaches of the performance-based seismic design method are compared among EU, the US and Japan. Unfortunately, the design method in Japan does not show the safety target in the guidelines. Then a simple evaluation approach to obtain the safety index is proposed herein. The different performance of two actual pipeline systems is compared, in which one pipeline system demonstrated a good performance for 2011 East Japan Great Earthquake, and the other did not. In state-of-the-art study, the seismic experiments and design method of expansion joints are described, because the ultimate limit performance of the expansion joints has not been explicit, although many seismic damages have occurred at the locations of vulnerable expansion joints.