KEY GEOLOGICAL SAFETY ISSUES IN PUMPED STORAGE PROJECTS OF COMPLEX TECTONIC ZONES: REVIEW AND PROSPECTS

There are four issues in the research on the key geological safety of pumped storage engineering in complex structural areas. (1)The detection accuracy of fracture structures between the upper and lower reservoirs is not compatible with the engineering geological safety risk assessment. (2)The scarcity of observational data limits the understanding of seismic amplification mechanisms in the upper reservoir,resulting in insufficient design basis. (3)The chain-type risk prevention and control technologies for high-elevation landslides and debris flows under extreme rainfall and seismic events remain to be improved. (4)The evaluation of long-term high-frequency water level fluctuations and the associated structural deterioration of the upper reservoir slopes urgently needs refinement. It is recommended to focus on the following key research directions:(1)Develop advanced intelligent exploration technologies for detailed fracture structure detection to enable precise identification of complex structures and dynamic updating of geological parameters. (2)Establish a standardized seismic motion observation network covering multiple terrain and geomorphological units to reveal the nonlinear threshold characteristics and spatial heterogeneity of seismic amplification effects,and construct a seismic design theoretical framework for high-elevation reservoirs based on dynamic seismic amplification. (3)Elucidate the chain disaster process involving landslide-debris flow initiation,multi-level blockage and dam breach,and reservoir inflow under extreme conditions,and develop an integrated prevention and control system encompassing source identification,multi-level blockage,channel erosion,and reservoir disaster formation. (4)Conduct multi-factor coupled analysis and real-time dynamic assessment of disaster mechanisms,and improve fatigue damage mechanisms and models for rock masses and slope protection structures in the reservoir drawdown zone under extreme conditions and high-frequency large water level fluctuations.