Research On The Effects Of Roadway Excavation Of Rock Damage The Structure Of The Face

The generation and propagation of structural plane in rock masses has an important impact on the damage zone and the stability of the rock masses around the tunnel in the excavation process. Therefore, the main objective of this paper is to investigate the damage of the rock masses around the tunnel in the excavation process. The main research contents and conclusions of this paper are summarized as follows:(1) The basic information and monitored behavior of the Mine-by test tunnel in URL was selected as simulated data and using finite element model to simulate excavation of Mine-by tunnel. The analysis results including the shape, the size and the location of excavation damage zone (EDZ) around the Mine-by test tunnel are in good agreement with the monitored behavior of Mine-by tunnel. It proved that finite element model can predict the damage of underground carven caused by excavation efficiently.(2) Simulation and analysis of the EDZ controlled by structural plane are based on the basic characteristics of the structural plane and granitic masses of Beishan by using brittle material elastic-plastic damage model and extended finite element method (XFEM) plastic damage model separately. The former can analyze the location and scale of damage zone and the possibility of both tensile and compressive damage caused by excavation; the latter can analyze the possibility and form of crack propagation.(3) the damage of rock masses around tunnel caused by excavation are influenced significantly by the parameters including location, dip and shear strength of single structural plan and the combinational form of multi structural planes proved by the simulation analysis The numerical investigation demonstrates that:the case of cracks intersecting the sidewall of tunnel have the greatest effect on the damage of rock masses around tunnel; the case which the crack dip is65°have the most significant influence on the damage of rock masses around tunnel; the shear strength of structural plane has little impact on the damage of rock masses around tunnel, because friction dips of the granitic rock structural plane of Beishan are sufficiently large; the case which has two or more non-parallel structural planes located at the roof of the tunnel is the most unfavorable for the damage and stability of rock masses around tunnel.