Rockfall impacts on sand cushions with different soil mechanical characteristics using discrete element method
Rockfall impacts on sand cushions with different soil mechanical characteristics using discrete element method
复制标题
DOI：
10.1016/j.sandf.2020.02.008
复制
发表时间：
2020-04
影响因子：
3.7
通讯作者：
N. Naito;K. Maeda;H. Konno;Y. Ushiwatari;Kentaro Suzuki;R. Kawase
中科院分区：
文献类型：
--
作者：
N. Naito;K. Maeda;H. Konno;Y. Ushiwatari;Kentaro Suzuki;R. Kawase
采用离散元法（DEM）对崩塌防护岩棚的合理设计和性能评价进行了数值模拟研究。到目前为止，进行的几个数值分析研究都集中在最大冲击力上，这取决于缓冲材料的层厚度和坠落条件。然而，为了正确研究砂垫层的缓冲性能，并提出有效合理的措施，必须考虑土的压缩和膨胀特性，这是与变形相关的特性。因此，在这里提出了一种方法来确定一个二维离散元模拟的参数，以考虑土壤力学特性的落石冲击的砂垫层的问题。所提出的方法进行了验证，通过比较的模拟和实验结果，使用大规模的落重冲击不同层厚度的砂垫层，初始相对密度，和下降的高度的下降质量。不仅比较了最大冲击力，还比较了冲击实验后缓冲材料的密度变化。本研究有助于阐明高速荷载作用下土体的变形机理，并根据变形特性评价砂垫层的性能。
The cushioning behavior of materials, such as sand, is numerically studied using a discrete element method (DEM) for the rational design and performance evaluation of a rock shed intended for rockfall protection. Several of the numerical analysis studies, conducted thus far, have focused on the maximum impact force which depends on the layer thickness of the cushioning materials and the falling conditions. However, to investigate the cushioning performance of a sand cushion correctly and to propose effective and rational measures, the compression and expansion behaviors, which are characteristic of soil associated with deformation, should be considered. Therefore, a method is proposed here for determining the parameters of a two-dimensional DEM simulation in order to consider the soil mechanical characteristics for the problem of rockfall impacts on a sand cushion. The proposed method was validated through a comparison of the simulation and experimental results using large-scale falling-weight impacts for different layer thicknesses of the sand cushion, initial relative densities, and falling heights of the falling mass. Not only were the maximum impact forces compared, but also the changes in density of the cushioning material after the impact experiment. The present study contributes to the elucidation of the deformation mechanism of soil under high-speed loading and evaluates the performance of a sand cushion considering its deformation behavior.