关键词: 地下洞室; 控制性断层; 变形规律; 塑性区演化; 衬砌破坏形态;

Abstract: Controlling faults that intersect underground caverns are one of the main factors influencing the cavern stability and inducing liner damages,and has become one of the main concerns for excavations.Based on a pumped storage power station in Fengning City,Hebei Province in China,FLAC3D software was used to carry out a three-dimensional simulation of the excavation process of the underground caverns with consideration of two controlling faults.The joint elements were used to simulate the interaction between the rock mass and the faults,and the effects of the faults on the stress redistribution,deformation development and plastic zone development were studied.The strength check method for the liners was used to study the failure modes of the liners at the faults.The results showed that:(1)The stress of the rock masses at the faults was discontinuous.The plastic zone near the fault was distributed in a strip extending from the openings to the deep rock masses.(2)The vertical deformations of the upper rock masses increased at the faults and the rebound deformations of the lower rock masses decreased at the faults.The upper rock mass at the consequent fault at the high side walls was prone to slide along the fault to the free face.(3)The slide of the rock mass at the faults was the main factor inducing the liner cracks.The failure modes of the liners were mainly the tension-bending and tension-shear failures,supplemented by the compression-bending and compression-shear failures,which were consistent with the practical failures,including bulging,pulling,crushing and shearing failures occurring on the liners.(4)Finally,corresponding treatments are proposed for the problems of the liners at the faults.

Key words: underground cavern; controlling fault; deformation characteristics; evolvement of plastic zone; liner failure modes;