TY -的A2 -史,验钞AU -罗,永盟,龚Fengqiang盟——刘Dongqiao PY - 2020 DA - 2020/10/31 TI - Unloading-Induced红色砂岩的实验调查失败:洞察剥落机理和强度弱化效应SP - 8835355六世- 2020 AB -研究开挖卸荷的影响在坚硬的岩石失败,一系列的真三轴压缩试验、双轴压缩测试,和真三轴卸载压缩测试(两个不同的卸率)进行了不同围压在红色砂岩多维数据集样本。力量和故障特点和他们的关系对红砂岩卸货卸率和不同围压进行了分析。根据测试结果,卸货率和围压的影响强度和故障特征的坚硬的岩石进行了探讨,和一个合理的解释在坚硬的岩石隧道unloading-induced剥落。结果显示高度紧张的红色砂岩的应力-应变曲线表现出压力一步卸货期间,和卸货率越高,压力越低压力所需的步骤。岩石强度弱化效应引起的卸货确认。红色砂岩的力学性能和复杂的卸货后变得更加不稳定。红色砂岩后卸载到一个二维应力状态,随着围压增加,强度增加,然后减少;失效模式的变化从一个low-confining压力tensile-shear未能高围压拉伸断裂;和板的几何图形变化从大型厚板和楔形中小薄盘子。在相同围压,卸载率越高,强度越低(即。, the strength-weakening effect is more pronounced), the thinner the slab, and the lower the confining pressure required for the failure mode to change from tensile-shear failure to tensile failure. The unloading rate and confining pressure affect the strength and failure characteristics by affecting the crack initiation type and propagation direction in hard rock. For deep hard rock tunnels with high unloading rate and axial stress, neglecting the effects of unloading rate and axial stress will lead to a dangerous support design. For deep hard rock ore, if the maximal horizontal principal stress exceeds the critical confining pressure, the mining surface should be perpendicular to the direction of the minimal horizontal principal stress. The results of this study are of great engineering significance for guiding deep hard rock tunnel construction and mining. SN - 1687-8086 UR - https://doi.org/10.1155/2020/8835355 DO - 10.1155/2020/8835355 JF - Advances in Civil Engineering PB - Hindawi KW - ER -