泥石流冲击特性模型试验

针对沟谷泥石流,建立了泥石流冲击试验模型,选定0.3～0.8cm、0.8～15cm和1.5～3.0cm等3种固相粒径组和0.02、0.08、0.16、0.20、0.25等5种固相比,拟定了15种水石流试验工况;实施了40余组模型试验,采用Fastcam-ultima1024型高速摄像机、HS200型动态应力传感器和多通道动态应变仪等测试仪器获得了85000多个测试数据。试验结果表明,低固相比时,泥石流脉动特征显著,泥石流阵流特性随着固相比增大逐渐显现,且随着泥石流中固相颗粒粒径增大,出现初始阵流的时间提前;随着固相比及固相颗粒粒径的增大,泥石流冲击力具有非线性增加趋势;泥石流沟口的平均流速随着固相比增大具有降低趋势。成果可为系统实施不同浆体粘度及不同固相比泥石流冲击特性试验及理论研究提供科学借鉴。

Experimental model of debris flow impact features

This paper developes the physical experimental model for the valley-shaped debris flow, and draw up 15 operating modes in accordance with three sets of particle solids at 0.3~0.8 cm, 0.8~15 cm and 1.5~3.0 cm in diameter and fluid at the solid to liquid (RSL) rate of 0.02, 0.08, 0.16, 0.20 and 0.25. It conducts more than 40 simulations, and obtained 85 000 data using the new test methods such as Fastcam-ultima1024 typed CCD camera, HS200 typed dynamic transducer and multi-channel strain instrument. The experimental results show that the debris flow fluctuation becomes obvious at low RSL, the debris flow surge gradually embodies with the increase of RSL and the initial surge appears ahead of time with the increase of particle diameter. The impact forces of debris flow trend to increase nonlinearly with the increase of RSL and particle diameter, however, the flow speed at the mouth of debris flow valley trend to decrease with RSL increase. The studies may produce some valuable enlightenment in debris flow impact simulations and theory basis for various slurry viscosity and RSL.