随机分布贯穿裂隙岩体变形特性研究

洞室开挖后，其周边通常会产生许多随机分布的贯穿裂隙，直接影响洞室围岩稳定，研究随机分布贯穿裂隙岩体的变形及变形特性具有重要意义。基于线弹性理论和线性刚度理论计算岩石和裂隙的位移，用概率的方法建立了随机分布贯穿裂隙岩体变形的计算模型，给出了随机分布贯穿裂隙岩体的等效弹性模量和等效泊松比，研究了岩石和裂隙的材料参数和几何参数对岩体等效弹性模量和等效泊松比的影响。可得如下结论：等效弹性模量和等效泊松比随着岩石弹性模量的增大而增大；等效泊松比随着岩石泊松比的增大而增大；等效弹性模量和等效泊松比随着裂隙法向刚度的增大而增大；随着剪切刚度的增大，等效弹性模量逐渐增大，而等效泊松比则逐渐减少；随着裂隙平均间距的增大，等效弹性模量逐渐减小，等效泊松比在平均倾斜角较小时逐渐增大，在平均倾斜角较大时逐渐减小；随着裂隙平均倾斜角的增大，等效弹性模量先减小后增大，而等效泊松比先增大后减小。模型能较全面地考虑构成岩体的岩石和裂隙的材料参数与几何参数对岩体变形的影响，其结果对研究洞室围岩的变形和工程设计有一定的参考价值。

Study of deformation characteristics of rock mass with stochastic distribution of penetrative cracks

After excavation of caverns,the surrounding rock mass of them usually generates a lot of stochastic distribution of penetrative cracks which directly affects the stability of surrounding rock mass.It is important to study the deformation and deformation characteristics of rock mass with stochastic distribution of penetrative cracks.Based on linear elastic theory and linear stiffness theory,the computational model of deformation of rock mass with stochastic distribution of penetrative cracks is established by probabilistic approach.Equivalent elastic modulus and equivalent Poisson’s ratio are also presented.The effects of material parameters and geometry parameters of rock and cracks on the equivalent elastic modulus and equivalent Poisson’s ratio of fractured rock mass are studied.The following conclusions can be concluded: the equivalent elastic modulus and equivalent Poisson’s ratio all increase with the increase of elastic modulus of rock.The equivalent Poisson’s ratio increases with the increase of Poisson’s ratio of rock.The equivalent elastic modulus and equivalent Poisson’s ratio all increase with the increase of normal stiffness of cracks.With the increase of shear stiffness of cracks,the equivalent elastic modulus increases,while equivalent Poisson’s ratio decreases.With the increase of mean space of cracks,the equivalent elastic modulus decreases,while the equivalent Poisson’s ratio increases when the mean dip is smaller and decrease when mean dip is larger.With the increase of mean dip of cracks,the equivalent elastic modulus firstly decreases and then increases,while the equivalent Poisson’s ratio firstly increases and then decreases.The model can more comprehensively consider the effects of material parameters and geometry parameters of rock and cracks on the deformation of rock mass.So the model has some reference value in studying deformation of surrounding rock mass of caverns.