论文部分内容阅读
滚石灾害是5.12地震诱发的主要次生山地灾害之一,因具有随机和不可预见性,成为灾后重建中地质灾害防治的难点。滚石防治的核心问题是解析滚石对坡面的冲击响应,由于冲击过程历时短、变形大和能量转换复杂,通过传统理论分析方法分析较为困难。为此,以Hertz理论为基础,考虑坡体的弹塑性特性,模型化滚石冲击为自由落体冲击的半无限体问题,运用动力有限元数值仿真技术,研究了滚石对坡面法向冲击特性,揭示滚石冲击速度、滚石半径对坡面土体动力响应的影响。结果显示基于弹塑性冲击理论的计算结果与数值模拟结果较为吻合,而完全弹性冲击理论的计算结果偏差较大,即基于弹塑性理论的滚石灾害防护设计更为合理。
Rolling Stone Disaster is one of the major secondary mountain hazards induced by the 5.12 earthquake. Due to its randomness and unpredictability, it has become a difficult point to prevent and control geological disasters in post-disaster reconstruction. The core problem of rock control is to analyze the impact response of rock on the slope. Because of the short duration of impact, large deformation and energy conversion, it is difficult to analyze by traditional theoretical analysis method. Based on Hertz theory, considering the elasto-plastic characteristics of the slope and modeling the impact of the rolling rock as a semi-infinite body with free-falling impact, the dynamic finite element numerical simulation technique is used to study the impact of the rolling stone on the normal impact of the slope, The influence of the impact velocity of rolling stone and the radius of rolling stone on the dynamic response of soil mass is revealed. The results show that the calculation results based on the elasto-plastic impact theory are in good agreement with the numerical simulation results, while the results of the complete elastic impact theory deviate greatly. That is to say, the rock-roll disaster protection design based on elasto-plastic theory is more reasonable.