不同应力路径对岩石剪切力学参数及破坏响应的影响  

Influence of different stress paths on shear mechanical parameters and failure response of rock

作　　者：周炳昊 孙钱程 徐平 徐晓 ZHOU Binghao;SUN Qiancheng;XU Ping;XU Xiao(National Field Observation and Research Station of Landslides in Three Gorges Reservoir Area of Yangtze River,Yichang 443002,Hubei,China)

机构地区：[1]湖北长江三峡滑坡国家野外科学观测研究站,湖北宜昌443002

出　　处：《水利水电技术(中英文)》2024年第11期176-187,共12页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金(51909136);防灾减灾湖北省重点实验室(三峡大学)开放基金(2022KJZ15)。

摘　　要：【目的】边坡岩体经历复杂的应力路径与受力模式,考虑岩体实际受力环境开展相应的力学试验,进而获取岩体力学参数,对边坡稳定性分析及安全评估具有重要意义。【方法】以红砂岩为例,通过室内试验研究其在不同应力路径和剪切模式下的力学参数特征和破坏响应,其中应力路径包括轴向压缩和轴向剪切,而剪切模式包括常规切向加载剪切和法向卸荷剪切,分析内容包括岩石的破坏模式、剪切力学参数和细观机理。【结果】结果显示:(1)不同应力路径下,岩石破坏模式有明显差异,主要表现在试样的贯通裂纹与端面或剪切面的夹角、主裂纹的偏差和岩块的脱落;(2)不同应力路径下,岩石的剪切力学参数也有明显差异,主要表现在黏聚力和内摩擦角的变化规律;(3)数值模拟结果显示,不同应力路径下,岩石的细观机理存在差异性,主要是由于骨架颗粒和充填胶结物质的作用。【结论】揭示了不同应力路径对岩石剪切力学参数及破坏响应的影响,可为边坡岩体的力学特性和稳定性评价提供参考。[Objective]The rock mass of the slope experiences complex stress paths and stress modes.Considering the actual stress environment of the rock mass,the corresponding mechanical tests are carried out to obtain the mechanical parameters of the rock mass,which has an important influence on the stability analysis and safety evaluation of the slope.[Methods]Taking red sandstone as an example,using conducted laboratory tests to study its mechanical parameter characteristics and failure response under different stress paths and shear modes.The stress paths include axial compression and axial shear,while the shear modes include conventional tangential loading shear and normal unloading shear.The failure modes,shear mechanical parameters and micromechanism of the rock were analyzed.[Results]The results show that:(1)there are obvious differences in rock failure modes under different stress paths,which are mainly manifested in the Angle between the through crack and the end face or shear plane,the deviation of the main crack and the fall off of the rock block.(2)Under different stress paths,the shear mechanical parameters of rocks also have obvious differences,which are mainly manifested in the changes of cohesion and internal friction Angle.(3)Numerical simulation result show that there are differences in rock mesoscopic mechanism under different stress paths,mainly due to the action of skeleton particles and filling cementing materials.[Conclusion]The research results reveal the influence of different stress paths on shear mechanical parameters and failure response of rock,which provides a useful reference for the evaluation of mechanical properties and stability of rock slope.

关 键 词：砂岩 剪切特性 三轴压缩 切向加载 法向卸荷 细观机理 影响因素 模型试验 

分 类 号：TU458.3[建筑科学—岩土工程]