高拱坝蓄水期库岸变形与水库诱发地震相关性研究  

Relationship between reservoir bank deformation and reservoir-induced earthquakes during the impounding of high arch dams

作　　者：王兴旺 刘耀儒[1] 吕帅 杨强[1] WANG Xingwang;LIU Yaoru;LÜShuai;YANG Qiang(State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China;Xuzhou Water Bureau,Xuzhou 221018,China)

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [2]徐州市水务局,徐州221018

出　　处：《清华大学学报（自然科学版）》2022年第8期1341-1350,共10页Journal of Tsinghua University(Science and Technology)

基　　金：国家重点研发计划资助(2018YFC0407005);国家自然科学基金项目(41961134032,51739006)。

摘　　要：高拱坝蓄水过程中观测到了库岸变形和水库诱发地震现象,水库诱发地震可能是边坡大范围变形的前兆,这给高拱坝的长期、高效和安全运行带来了巨大挑战。基于对溪洛渡拱坝蓄水期库岸变形监测资料的分析和对蓄水前后地震监测数据的分析,研究了蓄水后库岸变形的规律以及蓄水前后库区地震活动的变化规律,对水库蓄水后库岸变形和水库诱发地震的产生机理以及它们之间的相关性进行了研究。结果表明,库岸变形和水库诱发地震在规律和机理上均存在一定的相关性,两者都存在快速响应和滞后响应的特征,经历了由快变慢再到平缓的过程。快速响应是由于水的力学作用导致有效应力降低,产生了不可逆塑性变形和断层滑动。滞后响应是由于库水的物理化学作用降低了岩体和断层的抗剪强度,导致岩体的缓慢变形和断层的滑动。两种现象在规律和机理上的相关性为高拱坝蓄水期的智能监测和安全预警提供了新思路。Reservoir bank deformation and reservoir-induced earthquakes have been observed during the impounding of arch dams.Reservoir-induced earthquakes may be precursors of widespread slope deformation,which can endanger the long-term,efficient and safe operation of arch dams.This paper presents an analysis of deformation monitoring data and seismic monitoring data before and after impounding of the Xiluodu arch dam.The results compare the reservoir bank deformation and the seismic activity variations in the reservoir area before and after impoundment which were used to analyze the mechanisms relating the reservoir bank deformation and the reservoir-induced earthquakes.The results show that the two processes are correlated with initially fast responses including hysteresis transitioning to slower responses and then to constant values.The fast response is due to the reduction of the effective stress caused by the mechanical action of the water that leads to irreversible plastic deformation and fault slip.The hysteresis is due to the decreased shear strength of the rock mass and faults due to the physicochemical action of the reservoir water,which leads to slow deformation of the rock mass and the sliding of faults.The correlation between the two phenomena provides a basis for intelligent monitoring and safety warnings of high arch dams during impounding.

关 键 词：高拱坝 蓄水期 库岸变形 水库诱发地震 相关性分析 

分 类 号：TV62[水利工程—水利水电工程]