仙女山断裂与三峡库首诱发地震和滑坡的相关性

仙女山活动断裂诱发地震及其对滑坡的控制是三峡库首区重大地质问题。野外地层剖面记录表明,仙女山活动断裂经历了两次强烈抬升,为滑坡形成提供了物质基础;依据地震与滑坡在时间和空间上的相关性分析,仙女山断裂可能对新滩滑坡的产生具有控制作用;引入摩尔-库仑准则对仙女山断裂活动性进行分析后认为,库水位涨落引起断裂三维应力状态变化,且诱发地震在高低两极水位和蓄水回落阶段高发。该研究可为揭示仙女山活动断裂与地震和滑坡的相关性提供依据。

Correlations between Xiannushan active fault,reservoir-induced earthquakes and landslides located at head area of Three Gorges Reservoir

The earthquakes and landslides induced by Xiannushan active fault are the major geological problems in the head area of Three Gorges Reservoir (TGR). According to the records of the field stratigraphic profiles, the Xiannushan active fault had experienced two severe uplifts, which provided the material basis for the landslide formation. Based on the temporal and spatial correlation between the earthquakes and the landslides, Xiannushan fault may have controlling effects on the occurrence of Xintan landslide. The Mohr-Coulomb criterion is introduced for analyzing the activity of Xiannushan fault, which suggests that the fluctuation of the reservoir water level causes three-dimensional stress variation of the fault. Therefore, earthquakes are induced most likely at the highest and lowest water levels and in the water-fall period. This study can provide evidences for revealing the correlation between Xiannushan active fault, earthquakes and landslides.