含不同半径孔洞的颗粒体模型的力学行为数值模拟

Numerical simulation of mechanical behavior of the granular model with holes with different radii

本文通过编程建立了非连续介质(颗粒体材料)模型,采用FLAC软件模拟了静水压力条件下不同半径的巷道围岩中的剪切应变增量、最小主应力及最大主应力的分布规律。研究表明,随着孔洞半径的增大,呈圆环形的剪切应变增量与最小主应力的高值区的圈数、呈辐射状的最大主应力的高值区的延伸范围及剪切应变增量的最大值都呈先慢后快的增长趋势。模型中最大的拉应力接近于在模型四周所施加的压应力,而最大的压应力约为所施加的压应力的5～10倍。模型内部的剪切应变增量、最小主应力及最大主应力的分布是高度不均匀的。具有较高的差应力的位置与具有较高的剪切应变增量的位置具有很好的一致性。

In the paper,a discontinuum（granular assembly） model is established.The distributions of the shear strain increment,minimum principle stress and maximum principle stress in surrounding rock at a hydrostatic pressure are studied by using FLAC to simulate a circular tunnel with different radii when it is excavated.The annular regions with higher values of the shear strain increment and the minimum principle stress and the regions,in the radial direction,with higher value of the maximum principle stress are found.With an increase of the hole radius,the number of annular regions and the extending range of higher values of the maximum principle stress as well as the value of the maximum shear strain increment increase slowly and then gradually fast.The maximum tensile stress in the model is closer to the applied compressive stress acting on the boundaries of the model,while the maximum compressive stress is about five to ten times the applied compressive stress.It is found that the distributions of the shear strain increment,the minimum principle stress and the maximum principle stress are highly consistent.