Landslide dams composed of unconsolidated, noncohesive soil are easily affected by seepage. As seepage develops, the dam's characteristics change dynamically, indirectly affecting its stability. However, previous studies on dam failure have mostly assumed that the dam characteristics remain constant before failure, often overlooking these changes and their effects on stability. In this study, 48 sets of flume experiments were conducted to quantify the impact of seepage under varying upstream inflow rates, dam heights, downstream slope angles, and particle size distributions. During the storage phase, the rise rate of the water level is closely linked to the seepage's diversion capacity. The diversion rate of inflow reached as high as 0.747 in this study, but decreased to 0.230 as inflow increased. Furthermore, changes in the internal stress distribution within the dam, driven by seepage, contributed to dam settlement and the sliding of the downstream slope. Notably, dam settlement exhibited both non-uniform spatial distribution and temporal stage development. The maximum settlement ratio between the point in the upstream breach and the point in the downstream breach reached as high as 2.79. Regarding the soil changes within the dam, after the seepage channel became connected, the primary soil loss involved silt particles ranging from 10 to 20 μm in size. This result reflects the increasing non-uniformity within the dam caused by seepage. Finally, Considering the changes in dam characteristics under the influence of seepage, in this study, a logistic regression model was established to assess dam stability. Overall, this study enhances the understanding of how seepage affects dam stability by examining various dam properties and presenting a model for stability assessment.

中文翻译：

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基于渗流效应的非粘性滑坡坝稳定性试验研究


由未固结、非粘性土壤组成的滑坡坝很容易受到渗流的影响。随着渗流的发展，大坝的特性会动态变化，间接影响其稳定性。然而，以往关于大坝溃坝的研究大多假设大坝特征在溃坝前保持不变，往往忽视了这些变化及其对稳定性的影响。在本研究中，进行了 48 组水槽实验，以量化不同上游流入速率、坝高、下游坡角和粒径分布下渗流的影响。在储存阶段，水位的上升速度与渗流的分流能力密切相关。本研究中流入的分流率最高达到 0.747，但随着流入量的增加而下降到 0.230。此外，渗流驱动大坝内应力分布的变化导致大坝沉降和下游边坡滑动。值得注意的是，大坝沉降表现出不均匀的空间分布和时间阶段发展。上游突破点与下游突破点的最大结算比率高达 2.79。关于大坝内的土壤变化，渗流通道连接后，主要土壤损失涉及 10 至 20 μm 大小的淤泥颗粒。这一结果反映了渗漏导致大坝内部不均匀性的增加。最后，考虑渗流影响下坝体特征的变化，本研究建立了 logistic 回归模型来评估坝体稳定性。 总体而言，本研究通过检查各种大坝特性并提出稳定性评估模型，增强了对渗流如何影响大坝稳定性的理解。