Canadian Geotechnical Journal, Ahead of Print.
Sensitive clay landslides represent a significant geohazard due to their well-known potential for extensive retrogressive failures, on the scale of multiple hectares, which could encompass surrounding communities and infrastructure. Interpretation of retrogression mechanisms is often limited as only forensic investigations are possible. This work presents the results of a physical modelling study to examine retrogressive failures, analysis of each failure episode, and interpretation of the results using published relationships. Five novel centrifuge model tests were conducted under a defined range of undrained shear strength and slope angle conditions. The models are constructed of a sensitive cement–soil mixture that allows for a consistent contractile material with bespoke shear strength. Results indicate the observed retrogression distance correlates with Taylor’s stability number. The addition of a 5° slope angle to invoke a static shear stress on the model provoked notably larger retrogression distances. Post-test undrained shear strength measurements quantified softening of the material along the failure surface. Stability analyses on each failure episode captured the observed failure geometry and factor of safety. Results indicate that the geometric parameters of a slope, specifically the slope angle, may be able to explain a component of the scatter for relating Taylor’s stability number with retrogression distances.

中文翻译：

---

后退敏感粘土滑坡的岩土离心机模拟

加拿大岩土工程杂志，提前印刷。
敏感的粘土滑坡是一种重大的地质灾害，因为众所周知，它们可能会发生大规模的倒退失败，规模达数公顷，可能包括周围社区和基础设施。对倒退机制的解释通常是有限的，因为只有法医调查是可能的。这项工作展示了物理建模研究的结果，以检查倒退故障、每个故障事件的分析以及使用已发布关系对结果的解释。在规定的不排水剪切强度和倾斜角条件范围内进行了五项新型离心机模型试验。这些模型由敏感的水泥-土壤混合物构成，允许使用具有定制剪切强度的一致收缩材料。结果表明观察到的回归距离与泰勒稳定数相关。添加 5° 倾斜角以在模型上调用静态剪切应力会引起显着更大的后退距离。测试后不排水剪切强度测量量化了材料沿破坏表面的软化。对每个故障事件的稳定性分析捕获了观察到的故障几何形状和安全系数。结果表明，斜坡的几何参数，特别是斜坡角度，可能能够解释将泰勒稳定数与回归距离相关联的散点分量。测试后不排水剪切强度测量量化了材料沿破坏表面的软化。对每个故障事件的稳定性分析捕获了观察到的故障几何形状和安全系数。结果表明，斜坡的几何参数，特别是斜坡角度，可能能够解释将泰勒稳定数与回归距离相关联的散点分量。测试后不排水剪切强度测量量化了材料沿破坏表面的软化。对每个故障事件的稳定性分析捕获了观察到的故障几何形状和安全系数。结果表明，斜坡的几何参数，特别是斜坡角度，可能能够解释将泰勒稳定数与回归距离相关联的散点分量。