含软弱夹层岩质边坡动力劣化特性与时变稳定性
Dynamic Degradation Characteristics and Time-Dependent Stability Analysis of Rock Slopes with Weak Interlayers

含软弱夹层岩质边坡在内外动力耦合作用下极易失稳，可能引发灾难性后果。随着工程建设规模的扩大和矿产资源的深度开发，人类工程活动(如采矿爆破、山体开挖等)产生的动力扰动对边坡稳定性的影响日益显著。现有研究多聚焦于静态或瞬时动力条件下的边坡稳定性，而忽略了长期振动荷载导致的软弱夹层强度参数劣化及其时变效应。基于此，文章以含软弱夹层的岩质边坡为研究对象，综合运用室内试验和理论分析，系统探究了软弱夹层的动力学特性及其对边坡时变稳定性的影响。主要研究内容与成果如下：1) 通过振动三轴试验，研究了循环荷载作用下软弱夹层的动力响应特性。结果显示：随着振动次数的增加，软弱夹层的强度参数逐渐劣化，黏聚力和内摩擦角分别衰减了76.4%和26.9%；基于试验数据，建立了考虑“振次–频率”耦合效应的强度参数劣化数学模型。2) 基于极限平衡法和Mohr-Coulomb强度准则，结合软弱夹层动强度参数劣化模型，推导了边坡时变稳定性系数表达式。实例分析结果表明：边坡稳定性系数随振动时间延长呈渐进式衰减，最终趋于稳定。
Rocky slopes with weak interlayers are highly susceptible to destabilization under internal and external dynamic coupling, which may lead to catastrophic consequences. With the expansion of engineering construction scale and the deep development of mineral resources, the impact of dynamic disturbances generated by human engineering activities (e.g., mining and blasting, mountain excavation, etc.) on slope stability is becoming more and more significant. Existing studies mostly focus on the slope stability under static or transient dynamic conditions, but neglect the degradation of the strength parameters of the weak interlayer and its time-varying effects caused by long-term vibration loading. Based on this, we take the rocky slopes with weak interlayers as the research object, and systematically investigate the dynamic characteristics of the weak interlayers and their influence on the time-varying stability of the slopes by comprehensively using indoor experiments and theoretical analyses. The main research contents and results are as follows: 1) The dynamic response characteristics of weak interlayer under cyclic loading were investigated by vibration triaxial test. The results show that with the increase of vibration times, the strength parameters of weak interlayer gradually deteriorate, and the cohesion and internal friction angle are attenuated by 76.4% and 26.9%, respectively; based on the experimental data, a mathematical model of the deterioration of the strength parameters considering the coupling effect of vibration times-frequency is established. 2) Based on the limit equilibrium method and Mohr-Coulomb strength criterion, the expression of the time-varying stability coefficient of the slope was deduced by combining with the dynamic strength parameter degradation model of the weak interlayer. The results of the case study show that the slope stability coefficient decreases gradually with the prolongation of vibration time, and finally tends to be stabilized.