<p>Main mechanical parameters of the slope soil.</p>

Large-scale artificial surcharge loading often triggers landslides in colluvial deposits, yet the mechanical response and failure mechanisms of such slopes under loading remain insufficiently understood. Using a typical colluvial slope in Tibet as a case study, this research integrates physical model tests and FLAC3D simulations to investigate loading-induced deformation and failure processes. Analogous materials composed of river sand, barite powder, calcium carbonate powder, and water were prepared, and multiple regression analysis was used to establish empirical relationships between mix ratios and the resulting cohesion and internal friction angle, yielding high similarity (). Under loading, the slope exhibits maximum vertical and horizontal displacements of 40 mm and 50 mm, respectively, with shear stress concentrated along the loading boundary and vertical stress penetrating deeper than horizontal stress. The slope undergoes progressive failure: loading → initial equilibrium failure → rear-edge tensile cracking → upper soil mass sliding → front-edge extrusion and bulging → sliding surface propagation → overall failure. Furthermore, the colluvial slope exhibits pronounced failure sensitivity under loading, particularly in the progressive development of rear-edge tensile cracking, toe bulging, and deep shear bands, which should be regarded as key indicators for monitoring. These findings clarify the typical loading-induced failure mechanisms of accumulation-body slopes and provide a scientific basis for early landslide identification and hazard mitigation.大规模人工堆载常诱发坡积层滑坡，但目前学界对这类边坡在堆载作用下的力学响应与破坏机制仍认知不足。本研究以西藏某典型坡积边坡为研究对象，结合物理模型试验与FLAC3D数值模拟，探究堆载诱发的边坡变形与破坏过程。研究采用河砂、重晶石粉、碳酸钙粉末与水配制相似材料，并通过多元回归分析建立配合比与黏聚力、内摩擦角之间的经验关联，模型拟合度较高（）。堆载作用下，该边坡的最大垂直位移与水平位移分别为40毫米与50毫米；剪切应力集中于堆载边界区域，且垂直应力的影响深度大于水平应力。该边坡呈现渐进式破坏过程：堆载→初始平衡失稳→后缘张拉开裂→上部土体滑移→前缘挤压鼓胀→滑面扩展→整体破坏。此外，该坡积边坡在堆载作用下表现出显著的破坏敏感性，尤其体现在后缘张拉开裂、坡脚鼓胀与深部剪切带的渐进发育过程中，上述特征可作为边坡监测的关键指标。本研究结果明确了堆积体边坡典型的堆载诱发破坏机制，可为滑坡早期识别与灾害防控提供科学依据。