(1. State Key Laboratory of Hydraulics and Mountain River Engineering,College of Water Resource and Hydropower,Sichuan University,Chengdu,Sichuan 610065,China;2. School of Civil and Hydraulic Engineering,Shandong University,Jinan,shandong 250061,China;3. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute,Nanjing,Jiangsu 210029,China;4. School of Civil Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China;5. HydroChina Chengdu Engineering Corporation,Chengdu,Sichuan 610072,China)
Abstract:Plenty of seismic events have been recorded at the left bank slope of Jinping I hydropower station since the microseismic monitoring system was installed. On the basis of spatio-temporal analysis of microseismic activity at slope during the periods of excavation and reinforcement by grouting,rock mass damage regions were identified and delineated. However,how to utilize the abundant microseismic data effectively to quantitatively evalvate the stability of slope was the key issue of this study. First of all,research methods on rock slope stability were summarized and concluded. Then,the necessity of feedback analysis on slope stability based on microseismic monitoring was also outlined. A damage evolution model of rock mass based on microseismic data was put forward. The elements in the coverage of microseismic damage were searched automatically and their corresponding mechanical parameters were also reduced. The relation among microseismic activity induced by rock mass damage during slope instability processes,strength degradation and dynamic instability of slope was explored;and the slope stability was thus quantitatively evaluated. The results indicate:(1) The influence induced by rock mass actual damage could be taken into account based on three-dimensional feedback analysis of slope stability with microseismic monitoring. (2) The safety factor of rock slope considering microseismic damage effect decreased by 0.11,comparing to the case without regard to microseismic damage effect. This result demonstrated that microseismic activity induced by construction disturbances such as excavation and reinforcement by grouting had effect on stability of left bank slope. The feedback analysis method of 3D rock slope stability put forward in this study could be referred in stability evaluation of similar rock slopes.