深部软岩巷道开挖变形影响因素的数值分析

Numerical Analysis of Physics Influence Factors of Excavation Deformation in Deep Soft Rock

根据深部软岩巷道变形力学机理,采用不连续变形分析(DDA)软件对影响巷道开挖变形的岩体力学因素,包括地应力、围岩破裂面倾角、围岩块体弹性模量、围岩块体泊松比、围岩破裂面黏结力、围岩破裂面内摩擦角、围岩破裂面抗拉强度变化引起围岩变形位移的规律进行数值模拟研究分析。结果表明地应力是影响围岩变形的最重要因素,影响围岩变形的诸多因素指标存在临界值,得出了影响围岩变形位移的围岩特性因素重要性顺序,提出深部软岩巷道围岩控制的关键在于及时加固围岩以提高其残余强度,优化支护形式,在围岩中形成关键承载结构以阻止变形区的扩展。

According to the deformation physics mechanism of tunnels in deep soft rock,a number of simulation analyses with the software discontinuous deformation analysis（DDA）was carried out on the rule of displacement and deformation of surrounding rock caused by changes of factors influencing excavation deformation of tunnels,including the ground stress,angle of fracture plane,elastic modulus of rock block,poisson ratio of rock block,cohesion of fracture plane,internal fiction angle of fracture plane,tensile strength of fracture plane.The results showed that the ground stress is the most important factor influencing deformation of surrounding rock,and there is critical value in many indicators influencing deformation of surrounding rock.The importance sequence of rock characteristic influencing displacement and deformation of surrounding rock was reached.The opinion was put forward that the key of surrounding rock control in deep soft rock tunnels is to reinforce surrounding rock in time to improve its residual strength and optimalize supporting form to shape key bearing structure to prevent the development of deformation area.