鱼脊型泥石流水石分离结构适用性的模型试验研究

Applicability experiment of herringbone water-sediment separation structure for debris flow prevention

水石分离是泥石流工程防治常用的方法,现有水石分离结构均存在结构开口易被堵塞的现象。为了解决这一问题,我们曾设计了一种鱼脊型泥石流水石分离结构,但是该结构对不同类型泥石流的适用范围还有待深入研究。本文通过室内模型试验,模拟不同泥石流密度下的水石分离过程,进行对比试验,探讨泥石流密度对水石分离的影响。试验结果表明:在不同泥石流密度条件下,95%以上大于设计分离粒径的固体颗粒均会被分离出来,显示鱼脊型水石分离结构具有良好的分离粗颗粒能力,但是当泥石流密度大于1 900 kg/m3后,小于设计分离粒径的固体颗粒分离比例明显变大,结构排泄细颗粒的功能将减弱,而且水石分离前后泥石流密度变化不大,结构选择性分选砾石和调节泥石流密度的能力显著下降。对比结构的理想运行效果,得到该结构主要适用于密度小于1 900 kg/m3的泥石流。

Water-sediment separation is widely used in debris flow prevention project. The existing structures easily lose their water-sediment separation function because of blockage by the sediment. A new herringbone water-sediment separation structure had been designed to resolve such problem. In order to determine the application scope of this new structure with different bulk densities, a series of model experiments were conducted. Experimental results show that more than 95% of the sediment larger than design sediment is separated under all bulk densities, however, when the bulk densities is larger than 1 900 kg/m^3, separation ratio of the sediment smaller than design sediment is significantly increased, and the bulk density has little change before and after the separation. Comparing experimental results with effectiveness of the structure, the structure is mainly used to control debris flow which bulk density is smaller than 1 900 kg/m^3.