中文摘要：

许多岩石雪崩被 Wenchuan 地震在西南中国在 2008 年 5 月 12 日触发。被单个土壤层盖住的保护画廊通常被用来免于大量的落石。因为一个层保护画廊没有足够的缓冲区能力，一个二分层的吸收系统被设计了。这研究试图发现一个扩展 poly-styrol (EPS ) 垫子，为吃惊吸收在盖住土壤的保护画廊被使用，是否能在动态装载下面被放。在岩石雪崩的条件下面的二分层的吸收系统的动态影响数字地通过 2D 被模仿分离元素方法。由选择合理参数，一系列数字实验被进行为二分层的吸收系统发现最好的联合。EPS 层区域的价值作为全部的区域的一个百分比被放作为 0%(S ₁),22%(S ₂), 并且 70%(S ₃) 。EPS 层的 22% 区域被发现是合理的值，并且实验被进行在二分层的吸收系统发现 EPS 层的最好的位置。数字结果关于在影响雪崩和二分层的吸收系统之间的相互作用产出有用结论。土壤层能有效地吸收吃惊精力， S ₂( 厚 EPS 垫子用土壤层盖住的 0.4-m ) 是最有效的联合，它能减少影响力量，与另外的联合相比。

英文摘要：

Many rock avalanches were triggered by the Wenchuan earthquake on May 12, 2008 in southwest China. Protection galleries covered with a single soil layer are usually used to protect against rockfall. Since one-layer protection galleries do not have sufficient buffer capacity, a two-layered absorbing system has been designed. This study aims to find whether an expanded poly-styrol （EPS） cushion, which is used in the soil-covered protection galleries for shock absorption, could be positioned under dynamic loadings. The dynamic impacts of the two-layered absorbing system under the conditions of rock avalanches are numerically simulated through a 2D discrete dement method. By selecting reasonable parameters, a series of numerical experiments were conducted to find the best combination for the two- layered absorbing system. The values of the EPS layer area as a percentage of the total area were set as 0% （Sl）, 22~ （S2）, and 70% （$3）. 22~ of the area of the EPS layer was found to be a reasonable value, and experiments were conducted to find the best position of the EPS layer in the two-layered absorbing system. The numerical results yield useful conclusions regarding the interaction between the impacting avalanches and the two-layered absorbing system. The soil layer can absorb the shock energy effectively and S2 （0.4-m thick EPS cushion covered with soil layer） is the most efficient combination, which can reduce the impact force, compared with the other combinations.