关键词: 活动断层;错动量值;地震活动参数;概率分析方法;滇中引水工程;川滇地区;

Abstract: In the large-scale projects built in highly seismic regions in Sichuan-Yunnan of China, tunnel would inevitably come across with multiple regional active faults. Due to the dislocation of an active fault, the stability of the tunnels would face serious threats. In the anti-dislocation design of tunnels crossing active faults, the dislocation magnitude is the key design parameter. However, the fault dislocation magnitude determined by the traditional deterministic method can hardly reflect the random influence of fault dislocation induced by strong earthquakes, and thus the dislocation magnitude is often overestimated. In this paper, a probabilistic analysis method of dislocation magnitude estimation was introduced. The regional seismicity parameters and the probability of fault dislocation induced by earthquakes were considered. The seismic hazard would be evaluated by the probability that the fault dislocation may occur a given value during the service life of the project, so as to provide some references for the anti-dislocation design of tunnels crossing active faults. Taking Xianglushan tunnel as an example, the probability analysis method was demonstrated. The dislocation magnitude of the Longpan-qiaohou active fault that would be crossed by the tunnel was estimated and parameter analysis were carried out.

Key words: active fault; dislocation magnitude; seismicity parameter; probabilistic analysis method; Water Diversion Project in Central Yunnan Province; Sichuan-Yunnan region