Journal of Mountain Science

, Volume 14, Issue 7, pp 1428–1444

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

  • Lian-chong Li
  • Ya-zi Xing
  • Xing-zong Liu
  • Ke Ma
  • Nu-wen Xu
  • Fei Zhang
Article

Abstract

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 be identified. 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 36.2%. Both the numerical results and microseismic data show that the anti-shear galleries have a good reinforcement effect.

Keywords

Slope stability Microseismic monitoring Numerical simulation Safety factor Anti-shear gallery 

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Copyright information

© Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  • Lian-chong Li
    • 1
  • Ya-zi Xing
    • 2
  • Xing-zong Liu
    • 2
  • Ke Ma
    • 2
  • Nu-wen Xu
    • 3
  • Fei Zhang
    • 1
  1. 1.School of Resources and Civil EngineeringNortheastern UniversityShenyangChina
  2. 2.School of Civil EngineeringDalian University of TechnologyDalianChina
  3. 3.College of Water Resources and HydropowerSichuan UniversityChengduChina

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