Study on Bolt Support Effect Based on Mohr-Coulomb Strength Criterion
Starting from the mechanical characteristics of the interaction between surrounding rock and bolt,based on the surrounding rock enhancement theory,this paper uses numerical simulation to explore the mechanical characteristics of surrounding rock after tunnel excavation under bolt support,and obtains the surrounding rock characteristic curve(GRC curve).By comparing the difference between the characteristic curve of surrounding rock under various bolt support parameters and the characteristic curve of surrounding rock in the unsupported state,the relationship between bolt density and the reduction ratio of surrounding rock convergence is established.The results show that the bolt has a.significant limiting effect on the convergence of the surrounding rock,which can control the deformation of the surrounding rock,and the greater the density of the bolt,the more obvious the supporting effect.However,when the bolt density is greater than 3,its limiting effect on convergence begins to weaken.There is a limit value for the constraint effect of bolt on the convergence of surrounding rock,and the quadratic function relationship between bolt density and convergence reduction ratio is satisfied,and the limit of the limiting ratio of grade Ⅳ is 40.9％and that of grade Ⅴ surrounding rock is 33.8％.The restraining effect of bolt support on the convergence of surrounding rock is related to the nature of surrounding rock,and the constraint effect of grade Ⅳ surrounding rock is significantly better than that of grade Ⅴ surrounding rock.
tunnel boltsurrounding rock characteristicsconvergence-confinement methodsupport effectbolt densitynumerical simulation
万方数据
维普
