错动带对地下洞室群地应力场影响OA

To study the influence of shear zones on the distribution of in-situ stress field and stability of underground cavern groups,taking the right bank underground cavern groups at Baihetan Hydropower Station as the engineering background,a three-dimensional numerical model con-sidering the influence of shear zones is established based on engineering geological conditions and structural plane characteristics.Using numerical simulation methods,the initial in-situ stress field,excavation-disturbed stress field,and stress redistribution characteristics of surrounding rock of underground cavern groups under the existence of shear zones are systematically analyzed.The influence laws of different locations and mechanical parameter variations of shear zones on stress concentration,unloading zones,and plastic zone distribution of the cavern groups are emphatically studied.The results show that the existence of shear zones changes the stress transfer path of the rock mass around underground cavern groups,and obvious stress concentration is easily formed in the adjacent areas of shear zones,thus increasing the risk of deformation and failure of sur-rounding rock.When the spatial relationship between shear zones and cavern groups is close,the stress disturbance to the main caverns and adja-cent caverns is particularly significant.Under complex structural conditions,reasonably considering the influence of shear zones on the in-situ stress field is of great significance for stability evaluation and support design of underground cavern groups.The research results can provide a the-oretical basis and engineering reference for the site selection,layout,and safety control of underground powerhouses and cavern groups in similar large-scale hydropower projects.