NUMERICAL ANALYSIS ON SUPPORTING EFFECT OF SURROUNDING ROCK OF NUOZHADU LARGE UNDERGROUND POWERHOUSE

摘要

Base on the project layout and geologic conditions of large underground powerhouse of Nuozhadu Hydropower Station, the excavation process and supporting schemes are simulated by three-dimensional fast Lagrangian method (FLAC3D), the stress and displacement of surrounding rock are analyzed under different supporting conditions, and the stress of systematic bolts and anchor cable are determined. The calculation results are given as fellow: the excavation mode and sequence are basically reasonable; the supporting schemes are rational and remarkable; the method of simulating the bolts with cable element is more close to reality than approximate method; and more measure must be applied to adjust the stress concentrations and too bigger deformation in the partial area.