鱼脊型泥石流水石分离结构中格栅跨度的研究

鱼脊型水石分离结构是一种新型泥石流防治结构,为了使该结构具有最佳粗颗粒分离效果,必须确定水石分离格栅跨度的合理修建尺寸.通过理论分析建立了格栅跨度的理论计算公式,并得到格栅合理跨度的判别条件,即从引流坝引流口侧面流出的泥石流体中,粒径大于设计分离粒径的颗粒沿格栅滑落的时间等于其余泥石流体透过格栅的时间,然后利用模型试验对理论公式进行了检验与修正.假设泥石流在格栅上运动时仅受重力作用,根据上述判别条件得到格栅跨度与引流口宽度、引流口溢流深及格栅坡度3个参数有关,并建立了相应的格栅合理跨度理论计算公式.结果表明格栅合理跨度的理论计算值与实测值呈良好的线性关系(相关系数达到0.93),且实测值为理论计算值的1.53倍,说明理论计算值可以用该系数进行修正,据此建立了工程设计中格栅跨度修建尺寸的计算方法. 

Research on Grids Width of Herringbone Water-Sediment Separation Structure for Debris Flow Defense

A new herringbone water-sediment separation structure was designed to separate coarse sediment from debris flow. The width of water-sediment separation grids is key to separation effectiveness. A formula for grids width was proposed by theoretical analysis, A optimal width discriminant of grids was gived by theoretical analysis, that is, the movement time of sediment larger than design separation diameter sliding down grids is equals to that of the residual debris getting through grids. And then, model tests were developed to revise the formula. Only gravitational effect is considered, based on the above analysis, the theoretical formula consisting of the width and depth of overflow gate and the incline angle of grids is established. Tests results demonstrate that measured values are 1.53 times larger than theoretical ones, and the correlation coefficient is 0.93. The coefficient can be used to revise theoretical models.