A thermally induced wedging–ratcheting mechanism for slope stability is investigated using a large-scale physical model and using a three-dimensional version of the numerical Distinct Element Method (3DEC). The studied mechanism consists of a discrete block that is separated from the rock mass by a tension crack filled with a wedge block or rock fragments. Irreversible block sliding is assumed to develop down a gently dipping sliding plane in response to climatic thermal fluctuations and consequent contraction and expansion of the sliding and wedge block materials. A concrete block assembly representing the rock mass is placed in a specially designed climate controlled room. An integrated measurement system tracks the block displacement and temperature evolution over time. Results of the numerical 3DEC model and an existing analytical solution are compared with the experimental results and the sensitivity of the numerical and analytical solutions to the input thermo-mechanical parameters is explored. To test the applicability of our physical and numerical models to the field scale, we compare our numerical simulations with monitored displacements of a slender block that was mapped in the East slope of Mount Masada, as up until recently the governing mechanism for this block displacement has been assumed to be seismically driven. By application of our numerical approach to the physical dimensions of the block in the field we find that, in fact, thermal loading alone can explain the mapped accumulated displacement that has surpassed by now 200 mm. We believe this new, thermally-induced, failure mechanism may play a significant role in slope stability problems due to the cumulative and repetitive nature of the displacement, particularly in rock slopes in fractured rock masses that are exposed to high temperature oscillations.

中文翻译：

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岩坡中热致楔入-棘轮破坏机制

使用大型物理模型和三维版本的数值特征元法 (3DEC) 研究了用于边坡稳定性的热诱导楔入-棘轮机制。所研究的机制由一个离散块组成，该块通过充满楔形块或岩石碎片的张力裂缝与岩体分开。不可逆块滑动被假定为响应气候热波动以及随之而来的滑动和楔形块材料的收缩和膨胀而沿着缓慢倾斜的滑动平面发展。一个代表岩体的混凝土块组件被放置在一个专门设计的气候控制室中。一个集成的测量系统跟踪块位移和温度随时间的变化。将数值 3DEC 模型和现有解析解的结果与实验结果进行比较，并探讨数值和解析解对输入热机械参数的敏感性。为了测试我们的物理和数值模型对现场规模的适用性，我们将我们的数值模拟与绘制在马萨达山东坡的细长块体的监测位移进行比较，直到最近，该块体位移的控制机制已经假设是地震驱动的。通过将我们的数值方法应用于现场块的物理尺寸，我们发现，事实上，仅热载荷就可以解释已超过 200 毫米的映射累积位移。我们相信这种新的、热诱导的、