In order to study the mechanism of loading failure process of deep rock mass, particle flow numerical simulation (PFC2D) was used to carry out rock mechanical unit tests under different loading strain rates for sandstone in Haitangshan Tunnel, Fuxin. The applicability of several classical strength criteria was compared according to the test. The results show that, except Poisson’s ratio, the other mechanical parameters are positively correlated with the loading strain rate, including peak strength, elastic modulus, cohesion, internal friction angle and tensile strength. And the Poisson’s ratio is negatively correlated with the loading strain rate. And the crack initiation stress σ_ci and dilatation stress σ_cd increased gradually, but the effects on σ_ci/σ_pk, σ_cd/σ_pk and σ_ci/σ_cd were not obvious; and at the same volume strain, the corresponding axial strain decreased gradually. The anisotropy of normal and tangential contact forces between particles increases with the increase of loading strain rate. The normal contact force was approximately symmetrical distributed up and down, while the tangential contact force was approximately symmetrical distributed in the center. The cumulative number of cracks and the number of cracks every 10 steps gradually increased with the loading strain rate, and the crack development and failure degree gradually increased, and the crack hot spot map at the shear fracture zone gradually tended to be irregular. By comparing different strength criteria, it was found that the error of ROCKER strength criterion was relatively small, and the calculation was simple. It was considered that ROCKER strength criterion was more suitable for sandstone strength prediction under different loading strain rates.

为了研究深部岩体加载破坏过程的机理，采用颗粒流数值模拟（PFC2D）对阜新海棠山隧道不同加载应变率下的砂岩进行了岩石力学单元试验。根据测试比较了几种经典强度标准的适用性。结果表明，除泊松比外，其他力学参数与载荷应变率呈正相关，包括峰值强度，弹性模量，内聚力，内摩擦角和拉伸强度。泊松比与载荷应变率呈负相关。和裂纹萌生的应力σ _CI和扩张应力σ _CD逐渐增加，但在效果σ _CI / σ _PK，σ _CD / σ _PK和σ _CI / σ _CD不明显；在相同的体积应变下，相应的轴向应变逐渐减小。粒子之间的法向和切向接触力的各向异性随着载荷应变率的增加而增加。法向接触力在上下方向大致对称分布，而切向接触力在中心大致对称分布。裂纹的累积数和每10步的裂纹数随着载荷应变率的增加而逐渐增加，裂纹的发展和破坏程度逐渐增加，剪切断裂区的裂纹热点图逐渐趋于不规则。通过比较不同的强度准则，发现ROCKER强度准则的误差较小，计算简单。