To evaluate the large deformation of the Permian age slate interbedded with carbonaceous slate in Muzhailing Tun-nel,the bedrock,rock mass characteristics and engineering mechanical properties of the slate interbedded with the carbonaceous slate are analyzed and studied in detail by means of tunnel face sketch,grinding plate identification,X-ray diffraction,electrical microscope scanning,point load strength index test and large shear tests.The internal cause of the large deformation is also in-vestigated.Meanwhile,the analysis and the understanding of the squeezing bedrock are performed.The conclusions are as fol-lows:(1)the slate and the carbonaceous slate are composed of variable residual debris,peat and sericite,and the mineral parti-cles form a"laminar flow structure"under the strong directional stress,with the remarkable anisotropy;(2)the integrity of the rock mass is poor and the shear strength is low;the main type of the deformation and the fracture are bending and plastic flow;(3)it is a high geostress-weak expansion composite in the soft rock mass,which is a typical squeezing bedrock mass.
TunnelSlate BedrockRock Mass Integrity IndexSqueezing Rock MassLarge Deformation
万方数据
维普
