Geological structures and ground undulation affect the mobility of translational landslides. Combining field investigation, back-analysis, and numerical simulation, we explore the role of dominant joint dip angle in controlling the mobility of translational landslides. First, the attitudes of the geological structures are revealed by aerial photography measurements. The pre-failure slope surface of the Wolong landslide, Southeastern Tibetan Plateau, is estimated from the contours of the adjacent stable hillslopes and the deposit bottom boundary. Then, to back-analyze cohesion and internal fraction angle of the landslide, we fit a maximum stable relief limit based on Culmann’s model to the upper envelope of 96 rock scars and 37 previously published landslides. Next, we design eight scenarios (S1–S8) for the simulation of landslide mobility, respectively, corresponding to the eight joint dip angles between 20° and 60°. The mobility index H/L increases with the dip angle β, as confirmed by the best-fit line H/L = 0.288 ln(β) − 0.698. The numerical results of the runout characteristics, velocity, and energy consumption of the simulated landslides in the eight scenarios indicate that (1) the momentum losses at slope break are closely related to the joint dip, apparent friction angle, and height of the mass center; (2) local undulations in substrate have an inapparent effect on mobility of large and long runout landslides; and (3) conventional mobility indexes need to be improved or modified when high mobile landslides encounter high obstacles at slope bottom, opposite hills, or mountains. This study will be useful for hazard evaluations of translational landslides in mountainous regions.

地质结构和地面起伏影响平移滑坡的流动性。结合野外调查，反向分析和数值模拟，我们探索了主要的关节倾角在控制平移滑坡迁移率中的作用。首先，通过航空摄影测量揭示了地质构造的态度。青藏高原东南部卧龙滑坡的破坏前斜坡面，是根据邻近的稳定山坡轮廓和沉积物底部边界估算的。然后，为了对滑坡的内聚力和内部分数角进行反分析，我们基于库尔曼模型对96个岩石疤痕和37个先前公布的滑坡的上边界拟合了最大稳定起伏极限。接下来，我们设计了八种方案（S1-S8）来模拟滑坡的移动性，分别对应于20°和60°之间的八个关节倾角。流动性指数H / L随倾角β的增加而增加，这由最佳拟合线H / L = 0.288 ln（β）-0.698。在8种情况下模拟滑坡的跳动特性，速度和能量消耗的数值结果表明：（1）坡折处的动量损失与节理倾角，表观摩擦角和质心高度密切相关。 ; （2）基底上的局部起伏对大而长的跳动滑坡的流动性没有明显的影响；（3）当高活动性滑坡在斜坡底部，对面的山丘或山脉遇到高障碍物时，需要改进或修改常规的流动性指标。这项研究对于山区平移滑坡的危险性评估将是有用的。