考虑坝后淤积的泥石流冲击拦挡坝动力响应研究

在多期泥石流作用下，拦挡坝会部分或全部淤满，从而逐渐失去减灾能力。然而，关于坝后淤积体对泥石流拦挡坝减灾效果影响仍缺乏定量研究。为此，本文基于弱可压缩光滑粒子流（SPH），采用Drucker-Prager（DP）准则及Herschel-Bulkley-Papanastasiou(HBP）流变模型模拟泥石流与坝后淤积体相互作用的动力过程。首先，用该方法模拟了泥石流水槽物理模型试验，验证数值模拟方法的可靠性。在此基础上，对坝后淤积工况下红椿沟泥石流灾害的动力过程展开数值模拟研究，结果表明：在空库工况下泥石流过坝速度减小率为31.6%，在满库工况下速度减小率为6.5%，坝后淤积使拦挡坝削峰效应降低，显著降低其拦挡效果；同时坝后淤积改变泥石流冲击拦挡坝动力响应，在半库工况下坝体底部所受到的冲击力峰值相比空库工况减小13.25%，在满库工况下坝体顶部受到的冲击力峰值是空库工况的1.75倍。上述研究成果可为泥石流拦挡坝工程设计提供理论及技术支持。

Dynamic Response Analysis for Debris Flow Dam with Sediments

Under the affect of multiple debris flows, the debris flow dam will be partially or completely filling-up, and the function of disaster mitigation has been reduced. However, there is still lack quantitative research of sediments behind the dam on the debris flow dam disaster reduction effect. Therefore, based on the weakly compressible smooth particle flow (SPH), the Drucker-Prager (DP) criterion and the Herschel-Bulkley-Papanastasiou (HBP) rheological model are used to simulate the dynamic process of the interaction between the debris flow and the sediments behind the dam. The proposed method is verified by a flume experiment. On this basis, the model is further used to simulate the dynamic process of the Hongchungou debris flow disaster under sediments behind the dam. The research results show that the deceleration rate of debris flow through the dam is 31.6% under the condition of empty reservoir, and 6.5% for full reservoir conditions. The sediments reduces the peak clipping effect of the dam, which significantly reduces the blocking effect. At the same time, the sediments behind the dam changes the dynamic response of the debris flow dam, the peak impact force at the bottom of the dam under the half-reservoir condition is reduced by 13.25% compared to the empty reservoir condition, and the peak impact force at the top of the dam under the full-reservoir condition is 1.75 times compared to the empty reservoir condition. The research results can provide a basis for debris flow dam engineering design.