| In this paper,the factors affecting the surrounding rock stability of fault fracture zone,as well as the deformation and failure characteristics and mechanism are detailed.The main factors affecting the stability of surrounding rock of fault fracture zone are summarized.The three-dimensional simulation method of MIDAS-GTS software is used to study the mechanical behavior of the surrounding tunnel during tunnel excavation:the deformation law of surrounding rock is studied when different dip depths and footages and fault fracture zones have different dip angles and widths.Combined with the engineering example of the Haojiashan tunnel crossing the fault fracture zone of the Yubao Expressway,the deformation law of surrounding rock during excavation by the reserved core soil method is studied.The main results obtained in this paper are as follows:(1)Through the numerical simulation,the mechanical behavior of the tunnel crossing the fault fracture zone is summarized.When the tunnel is excavated,the optimal cycle footage is 3m when the depth is greater than 200m,and the optimal cycle footage is 2m when the depth is less than 200m.The general law of displacement is not affected by the conditions such as tunnel depth and footage,and the extrusion deformation value of the face is only affected by the tunnel depth;(2)The influence law of fault fracture zone with different forms on construction deformation,the variation trend of tunnel vault settlement value,elevation arch elevation value and arch waist horizontal displacement value are consistent with the dip angle of fault fracture zone;(3)Through the comparison and analysis of on-site monitoring data and numerical simulation results,the construction technology and supporting parameters of the tunnel crossing fault fracture zone are determined,which proves that the use of the advanced small conduit grouting technology has a significant effect on improving the stability of the surrounding rock of the fracture zone. |
PDF Full Text Request