Trajectory analysis is often needed to handle rockfall hazards. It is crucial to understand and to refine ground and rock interactions during a rockfall, which can be related to the elements involved. They include the topology, ground and rock nature, but also the volume and shape of the falling blocks. This work focuses on replicating field observations using a 3D discrete elements model (DEM) in order to further analyze the possible rockfall deposition areas, which may not be accessible due to the limited number of experimental data available. The numerical model implements blocks of more realistic shapes that were reconstructed from in situ blocks obtained by photogrammetry. The dissipation of kinetic energy at the collision point is suitably managed. In the experimental campaign, dozens of boulders (rock block) releases were conducted on two slope profiles of a quarry located in Authume (France). Block passing heights, velocities and runout distances were assessed at specific ground points. We analyzed lateral spreads, propagation distances, and energy balances computed for 3 different block geometries. These numerical results were confronted with experimental observations. Although time-consuming compared to lumped mass and rigid body dynamics models where the impact duration is zero, the DEM used in this work is versatile thanks to an explicit consideration of geometrical effects throughout the life of multiple contacts. It allows to simulate quite accurately a multitude of configurations. Among the properties of the terrain and the blocks, geometric features are shown to be crucial. For the sake of efficiency, a simplified shape coefficient based on block’s elongation is proposed.

通常需要轨迹分析来处理落石危险。理解和细化落石过程中的地面和岩石相互作用至关重要，这可能与所涉及的元素有关。它们包括拓扑、地面和岩石性质，还包括落块的体积和形状。这项工作的重点是使用 3D 离散元素模型 (DEM) 复制现场观测，以进一步分析可能的落石沉积区域，由于可用的实验数据数量有限，这些区域可能无法访问。数值模型实现了从通过摄影测量获得的原位块重建的更逼真形状的块。碰撞点处的动能耗散得到适当管理。在实验活动中，在位于 Authume（法国）的一个采石场的两个斜坡剖面上进行了数十个巨石（岩石块）释放。在特定的地面点评估块通过高度、速度和跳动距离。我们分析了为 3 种不同几何形状计算的横向扩散、传播距离和能量平衡。这些数值结果面临着实验观察。尽管与冲击持续时间为零的集总质量和刚体动力学模型相比，该模型耗时，但由于明确考虑了多个触点整个生命周期中的几何效应，因此在这项工作中使用的 DEM 是通用的。它允许非常准确地模拟多种配置。在地形和块的属性中，几何特征被证明是至关重要的。为了效率，