Study on the Influence of Fault Fracture Zone Morphology on Tunnel Surrounding Rock Deformation
Because of the characteristics of surrounding rock crushing,low intensity,fault fracture zone is easy to cause large deformation of tunnel surrounding rock,thus induce engineering disasters.Therefore,based on the Yun-wushan Tunnel project of Bitong Line of Chongqing suburban railway,PLAXIS3D numerical analysis software was used to establish the calculation model of tunnel through different fault fracture zones.The calculation results show that the dip angle and thickness of fault fracture zone have significant influence on the deformation of tunnel sur-rounding rock,while the angle between fault strike line and tunnel axis has little influence.With the increase of the dip angle of the fault fracture zone,the range affected by the fault fracture zone obviously reduce,and the vertical and horizontal displacement values of the tunnel surrounding rock gradually reduce.When the dip angle of the fault fracture zone is 90 °,the range affected by the fault fracture zone is the smallest;With the increase of the thickness of the fault fracture zone,the range affected by the fault fracture zone increases,and the vertical and horizontal dis-placement values gradually increase and reach the maximum value when the thickness of the fault fracture zone is 22 m.The deformation control effect of surrounding rock will be better when the tunnel crosses the weak part of the fault fracture zone.The research results can provide some reference for the design and construction of mountain tunnel through fault fracture zone.
fault fracture zonetunnel surrounding rock deformationnumerical analysisfault morphologyvertical displacementhorizontal displacement