复合型拦砂坝受泥石流大块石冲击作用的动力响应

Compound Dam Dynamic Response to the Impact of Massive Stone in Debris Flow

针对泥石流发生时,大块石对拦砂坝的撞击作用往往是拦砂坝发生破坏的主要原因,提出了一种新型拦砂坝——复合型拦砂坝。以充分耗散大块石撞击坝体时产生的大量能量为目的,在坝体迎水面采用堆积粗砂土体和铺塑料泡沫板2种措施。借助ABAQUS有限元计算软件,模拟计算了大块石不同冲击速度下,复合型拦砂坝及普通混凝土拦砂坝坝体对大块石冲击作用的动力响应,得到复合型拦砂坝坝体-大块石体系动能的动态演化规律及拦砂坝表面所受冲击力时间历程曲线,同时与混凝土重力拦砂坝进行比较。计算结果表明:在拦砂坝坝前堆积土体和铺塑料泡沫板可以延长大块石与拦砂坝冲击时间,减小拦砂坝接触面所受的冲击力。

Dams, as the line of defense against debris flow, play an important role in reducing the damage of debris flow, but they are often partial or complete failure due to the impact of large stone. In this paper, a new compound dam has been put forward. In order to reduce the energy generated by the massive stone impacting the dam, two measures （piling up coarse sand soil or laying plastic foam board） are proposed. With the finite element analysis software ABAQUS, a three-dimensional numerical model of the dam and the large stone is established. The compound dam dynamic response is simulated to the impact of massive stone in debris flow with different velocities, the impact force time history curve of the compound dam contact surface and the kinetic energy dynamic evolution law of the system of the dam and massive stone are obtained, and comparing with the concrete gravity dam. The results show that, in front of the dam, piling up coarse sand soil or laying plastic foam board can reduce the impact force at the dam contact surface.