基于SPH方法的废弃煤矿抽水蓄能地下水库扩容开挖模拟研究OA

The abandoned coal mine-based pumped-storage hydropower(PSH)technology offers significant advantages over conventional PSH systems.Taking the Daliuta Coal Mine as engineering background,using the Smoothed Particle Hydrodynamics(SPH)method to discretize the stratum rock mass into particle units with varying mechanical properties,and combining with elastoplastic model based on the Drucker-Prager yield criterion and a particle fracture model,the stress field evolution and roof failure mechanism of surrounding rock during the expansion excavation process of the abandoned coal mine-based pumped storage underground reservoir are dynamically simulated,and the influence of rock damage on the stability of surrounding rock is clarified.The results show that:(a)the roof failure occurs in stages,and the critical span of the roof is triggered when the excavation reaches 45 m,leading to stratified failure and local slab collapse,with a collapse zone height of up to 19.6 m;and(b)the rock mass damage significantly affects roof stability.Under the mild damage conditions of rock mass,the critical span will reduce to 35 m,and the water storage area is 90%of that in intact rock.Under the severe damage conditions of rock mass,the critical span will further reduce to 30 m,which will induce fracture initiation in the shallow layers of the roof,and exacerbate deep bending deformation,reducing the available space of the reservoir to 64%sharply.This study shows that SPH method can provide a theoretical basis for the stability analysis and control of roof rock in underground reservoir projects.