Study On The Stability Analysis And Control Of Underground Caverns Group In The High Geostress Nonuniform Soft Rock

The basic engineering geological characteristics is analysed and the engineering classification of high geo-stress nonuniform soft rock is discussed; the stress and deformation of high geo-stress nonuniform soft rock cavern group is numerical simulated by using structure software ANSYS; grouting reinforcement of broken rock is tested; the support scheme of high geo-stress nonuniform soft rock cavern group is proposed.Recording to Tangshan mine -950m pump chamber, the high geo-stress nonuniform soft rock stress and displacement distribution in wall rock when opening and with different support is researched by using 3-demision FEM.The failure of soft rock chamber is a dynamic problem. The new concept "disturbance creep" is proposed in the paper. Disturbance creep is creep under disturbance load in failure field of rock. Discuss the condition of disturbance creep occurred in wall rock underground.The failure and deformation reason of wall rock in high geo-stress nonuniform soft rock cavern group is analysised and the support principle of high geo-stress soft rock is proposed. This paper begins with a study of the deformation characteristics and the residual strength of broken rock, which is followed by a research of broken rock after grouting reinforcement. Testing results show that grouting can enhance the residual strength of broken rock, and improve the compatibility of lateral and vertical deformations. So the grouting rockmass can keep the steady supporting capacity in a relatively large deformation range. It is helpful for explaining the mechanism of the deformation control in roadway by grouting reinforcement in surrounding rock. On the base of principle of grouting bolt support and its technology, the stability and maintenance of cavern group is resolved by using grouting bolt united support according to Tangshan mine -950m pump chamber. With contrast experiment under the same geological condition, using grouting bolt united support under condition of soft rock is reasonable technically and economically.