鱼脊型泥石流水石分离结构的关键参数确定

Optimal Value of Structural Parameters in a New Water-sediment Separation Structure for Debris Flow Defense

鱼脊型水石分离结构是一种新型泥石流防治结构,该结构能有效解决现有水石分离结构不能持续发挥水石分离功能的问题。在工程设计中,为了使其具有最佳的运行效果,必须确定结构的设计参数,给出合理修建尺寸,其中水石分离格栅坡度θ和肋梁与脊梁夹角γ是两个影响水石分离效果的关键参数。通过开展室内模型试验,模拟泥石流在不同格栅坡度和肋梁与脊梁夹角下的水石分离过程;通过对比试验,探讨上述两个参数对水石分离的影响,从而确定其合理取值。试验结果表明：当格栅坡度θ为35°~38.7°、肋梁与脊梁夹角γ为70°~80°时,不仅结构能有分选地将粗颗粒分离出来,而且被分离的粗颗粒在重力下自动滑落到停积场,不堵塞格栅开口。根据一般砾石或卵石的天然休止角,以及结构的理想运行效果可知,实际应用中水石分离格栅坡度可以取为泥石流固体颗粒的天然休止角,肋梁与脊梁夹角的合理取值为70°~80°。

A new water-sediment separation structure with a herringbone water-sediment separation grid has been developed for debris flow defense. Compared to existing structures,this structure can continuously maintain its water-sediment separation function. In the design of the structure,the incline angle of herringbone water-sediment separation grid θ and intersection angle between ribbed beams and ridge beam γ should be determined. In this paper,in order to determined optimal value of the above parameters,a series of model experiments were developed.The experimental results show that the structure can only separating coarse particle,and the separated coarse particle can automatically leave the grid,when the grid incline angle θ and intersection angle between ribbed beams and ridge beam γ were 35° ~ 38. 7° and 70° ~ 80° respectively. According to structural optimum efficiency and the natural angle of repose of sediment,the grid incline angle θ can be equal to the natural angle of repose of sediment,and the intersection angle between ribbed beams and ridge beam γ can be 70° ~ 80°.