A block impact model based on the elasto-viscoplastic macro element approach is developed for regular base prismatic blocks. This model upgrades a previously conceived model for spherical boulders introducing (i) a rotational degree of freedom; (ii) a moment-rotation relationship; (iii) a toppling mechanism. The model can improve rockfall simulations by considering block geometry and the exchange between translational and rotational energies.

Model parameters were calibrated by using laboratory tests on vertical impacts. Parametric analyses were carried out to investigate for both vertical and inclined impacts, the effects of block shape and orientation. The influence of these factors on the impact force, the maximum penetration depth as well as the exchange between translational and rotational energies is discussed. A comparison with the available results for small and large scale laboratory tests shows model capabilities and put in evidence the “nonlinear” relationship between maximum acceleration (or equivalently the maximum contact force) and impact translational velocity.

For vertical impacts the trend of the maximum penetration depth is a function of the block shape. Prismatic blocks can experience larger values of maximum penetration than spherical blocks characterized by coincident masses and kinetic energies. In case of bouncing of a prismatic block the increment of normal maximum displacement with respect to spherical blocks ranges from about 66% for triangular base prisms to 132% for hexagonal base blocks. In case of no bouncing, the increments range from about 82% for triangular blocks to −32% for hexagonal blocks.

Maximum normal forces also depend on block shape and orientation. In case of a vertex impact with no bouncing, triangular blocks show a decrement in the maximum force of about 43% with respect to the spherical block. The increment of initial block angular velocity generates a reduction in both maximum penetration depths and impact forces.

基于弹粘塑性宏观单元方法的块体冲击模型被开发用于规则基础棱柱块。该模型升级了先前构想的球形巨石模型，引入了 (i) 旋转自由度；(ii) 力矩-旋转关系；(iii) 倾覆机制。该模型可以通过考虑块几何形状以及平移和旋转能量之间的交换来改进落石模拟。

模型参数通过使用垂直冲击的实验室测试进行校准。进行了参数分析以研究垂直和倾斜的影响、块体形状和方向的影响。讨论了这些因素对冲击力、最大穿透深度以及平移能和旋转能之间交换的影响。与小型和大型实验室测试的可用结果的比较显示了模型能力，并证明了最大加速度（或等效的最大接触力）与冲击平移速度之间的“非线性”关系。

对于垂直冲击，最大穿透深度的趋势是块体形状的函数。棱柱形块体可以比以重合质量和动能为特征的球形块体经历更大的最大穿透值。在棱镜块反弹的情况下，相对于球形块的法向最大位移增量范围从三角形基棱柱的 66% 到六边形基块的 132%。在没有反弹的情况下，增量范围从三角形块的约 82% 到六边形块的 -32%。

最大法向力还取决于块的形状和方向。在没有弹跳的顶点碰撞的情况下，三角形块的最大力相对于球形块减少了约 43%。初始块角速度的增加导致最大穿透深度和冲击力的降低。