乌鲁木齐地铁隧道互层围岩损伤演化规律模拟研究

Simulation of Damage Evolution Law of Surrounding Rock in Urumqi Subway Tunnel

为了研究乌鲁木齐地铁隧道穿越区强风化泥岩、砂岩所组成互层围岩的损伤演化规律,通过颗粒流软件标定已获取的强风化泥岩、砂岩所对应的微观参数,并组成不同几何特征的互层围岩进行单轴试验模拟,分析不同围岩层厚比、岩层倾角的力学特性及其中代表性3组裂纹的发展规律及能量演化。结果表明,围岩层厚比为0.2~0.6,围岩倾角为0°、20°、80°时,对互层围岩单轴抗压强度的影响较大;随着层厚比的继续增加,互层围压的单轴抗压强度的变化趋于平缓;不同的围岩层厚、岩层倾角组合试样有不同的破坏模式,对应的裂纹发展及能量演化也有较大差异。

In order to study the mechanical characteristics and failure mechanism of the interlayer surrounding rock composed of strongly weathered mudstone and sandstone in Urumqi subway tunnel crossing area,the micro-parameters of interbedded rock mass are calibrated on the basis of obtained physical and mechanical parameters of mudstone and sandstone by particle flow software,and the interlayer surrounding rock samples with different geometric characteristics are composed to conduct uniaxial test simulation.The mechanical properties of surrounding rock under different surrounding rock layer thickness ratio and rock layer inclination and the development and energy evolution of the three representative cracks in it are analyzed.The results show that,(a)when the thickness ratio of surrounding rock layer is 0.2-0.6 and the inclination angle of surrounding rock is0°,20°or 80°,the uniaxial compressive strength of surrounding rock is greatly affected;(b)with the continues increase of layer thickness ratio,the change of the uniaxial compressive strength tends to stabilize;and(c)different thickness and inclination combinations of rock formation have different failure mode in uniaxial compression,and the corresponding crack development and energy evolution are also quite different.