泥石流浆体冲击拦砂坝荷载计算的实验研究*

泥石流冲击力大小是泥石流灾害防治工程设计最重要的参数之一,但到目前为止,泥石流对拦砂坝的冲击力计算还存在很大争议。本文通过在拦砂坝上安装冲击力传感器测量冲击力值,详细分析不同容重泥石流,不同沟道坡度及不同拦砂坝迎水面倾角等因素下泥石流对拦砂坝坝体的冲击作用。研究表明,影响泥石流浆体冲击力大小的主要因素有泥石流容重、沟床坡度和泥石流流速;在沟道坡度和泥石流总量相同时,泥石流浆体冲击力大小随泥石流容重的增加而降低;在泥石流容重不变时,随沟道坡度的增加而增加;泥石流容重和沟道坡度的影响主要反映到泥石流流速的变化中,推导出新的泥石流浆体冲击力大小计算公式;该公式表明,泥石流浆体冲击力大小同泥石流表面流速呈正比例关系,而比例系数因泥石流容重的不同而不同。分析比较了新公式同原有公式的差异,并举例说明了新计算公式的实用价值,为泥石流防治工程设计提供技术支撑。

Experimental Study on Debris Flow Slurry Impact

The debris flow impact size is one of the most important parameters for designing debris flow hazards prevention project, but so far, there is a dispute of the calculation of debris flow impact. This paper analyzes the different debris impacts on the debris dam under different densities of debris flow, channel slope and the angle of debris dam to meet the water through the indoor flume experiment testing. This research shows that the main factors influencing the debris flow impact size is debris flow density, channel slope, and debris flow velocity; Other factors are equal. Debris flow impact size decreases with increasing of debris flow density, increases with the increase of channel slope; Debris flow density and the channel slope mainly reflect the influence of the change of debris flow velocity. We deduces a new formula of debris flow impact size. The formula shows that the debris impact size has a linear relation with debris flow velocity, and the linear coefficient varies because of the debris flow density. This paper compares the differences of the new formula with the original formula and illustrates the practical value and provides a technical support to new designing prevention projects of debris flow.