Interaction between anti-shear galleries and surrounding rock in the right-bank slope of Dagangshan hydropower station

• 来源期刊: 山地科学学报（英文版）
• 年，卷（期）: 2017,（7）
• 页码范围: 1428-1444
• 页数: 17页
• 语种: 英文
• DOI: 10.1007/s11629-016-4318-3

摘要

The right-bank slope of the Dagangshan hydropower station located in Southwest China is a highly unloaded rock slope.Moreover,large-scale natural faults were detected in the slope body;some excavation-induced unloading fractures were discovered at elevations between 1075m and 1146m.Because of poor tectonic stability,the excavation work was suspended in September 2009,and six largescale anti-shear galleries were employed to replace the weak zone in the slope body to reinforce the rightbank slope.In this study,based on microseismicmonitoring technology and a numerical-simulation method,the stabilities of the slope with and without the reinforcement are analysed.An in-situ microseismic-monitoring system is used to obtain quantitative information about the damage location,extent,energy,and magnitude of the rocks.Thus,any potential sliding block in the right-bank slope can beidentified.By incorporating the numerical results along with the microseismic-monitoring data,the stress concentration is found to largely occur around the anti-shear galleries,and the seismic deformation near the anti-shear galleries is apparent,particularly at elevations of 1210,1180,1150,and 1120m.To understand the interaction mechanism between the anti-shear gallery and the surrounding rock,a 2D simulation of the potential damage process occurring in an anti-shear gallery is performed.The numerical simulation helps in obtaining additional information about the stress distribution and failure-induced stress re-distribution in the vicinity of the anti-shear galleries that cannot be directly observed in the field.Finally,the potential sliding surface of the right-bank slope is numerically obtained,which generally agrees with the spatial distribution of the in-situ monitored microseismic events.The safety factor of the slope reinforced with the anti-shear gallery increases by approximately 36.a％.Both the numerical results and microseismic data show that the anti-shear galleries have a good reinforcement effect.