A PROBABILISTIC APPROACH TO EVALUATE PERMANENT DISPLACEMENT OF CAUSATIVE FAULTS
ZHAO Jisheng1，2，ZHOU Zhenghua2，3
(1. College of Civil Engineering，Beijing Jiaotong University，Beijing 100044，China；2. Institute of Engineering Mechanics，China Earthquake Administration，Beijing 100036，China；3. Institute of Mechanics，Chinese Academy of Sciences，Beijing 100190，China)
Abstract：A probabilistic approach to evaluate permanent displacement of causative faults is presented based on engineering seismic risk analysis frame work of Cornell，of which the parameters includes the fault model，probabilistic models for earthquake occurrence，the relations among of earthquake magnitude with rupture length，width and surface displacement. The parameters can be determined or verified by results of geophysical prospecting，inversion of kinematics source，historical earthquake data，site investigations and fault dating. In engineering technical points of view，the method adopts two suppositions，one is that all the potential earthquake of fault around the field point contributes to the earquake motion while only the fault contributes to the permanent displacement of the analysis field point；the other is that permanent displacement origins from only a few strong earthquakes on the fault，rather than strong ground motion origins from all earthquakes on the fault. The values of permanent displacement on Haiyuan fault in different probabilistic levels are given by using the data of seismic geology and characteristics of seismic activity. The objective of this research is to determine the value of permanent displacement of causative faults in different probabilistic levels，which have the same probabilistic levels of strong ground motion claimed on the code for a seismic design of buildings and the code for a seismic design of oil and gas steel pipelines of China. Based on the results，the engineers may take measures of to resist the displacement in pipeline and long bridge engineering to minimize loss caused by earthquakes.
