天然与人工滤层对渗管出水的影响

为了探究天然河床砂厚度对渗管取水工程出水量的影响,以及天然河床砂和人工反滤层的交互作用,通过物理模型试验,设置3种天然河床砂厚度、3种来流流量和不同水深,观测不同工况下渗管出水量的情况.根据试验结果进行回归分析.回归方程计算的出水量与试验值误差基本都在±5%以内,平均误差的绝对值仅为0.19%,较以往参考值算法更加精确;出水量的改变与天然河床砂渗透系数和人工反滤层渗透系数的大小有关,当天然河床砂的渗透系数小于人工反滤层最小渗透系数时,渗管出水量随着天然河床砂厚度的增加而减小;反之,则随着天然河床砂厚度的增加而增加.反滤层渗透系数对渗管出水量的影响要大于水头高度对出水量的影响.回归方程的方法提高了渗管出水量计算的精度,可用于实际工程的指导,在渗管取水工程的设计中需考虑天然河床砂与人工反滤层之间的交互作用,根据天然河床砂的渗透系数与厚度合理选择人工反滤层.

Effect of natural riverbed sand and artificial filter layer on water yield of permeation pipe

To explore the influence of natural riverbed sand thickness on water yield of permeation pipe and the interaction between natural riverbed sand and artificial filter layer,through physical model test,three kinds of natural riverbed sand thickness,three kinds of inflow discharge and different water depth were set up to observe the permeation pipe effluent under different conditions.According to the test results,the regression analysis was carried out.The error between the calculated water yield and the experimental value is less than±5%,and the absolute value of average error is only 0.19%,which is more accurate than the previous reference value algorithm.The change of water yield is related to the permeability coefficient of natural riverbed sand and artificial filter layer.When the permeability coefficient of natural riverbed sand is less than the minimum permeability coefficient of artificial filter layer,the water discharge of permeation pipe decreases with the increase of the thickness of natural riverbed sand,on the contrary,it increases with the increase of the thickness of natural riverbed sand.The influence of permeability coefficient of filter layer on the discharge of permeation pipe is greater than that of head height.The method of regression equation improves the accuracy of permeation pipe discharge calculation,which can be used as guidance for practical engineering.In the design of permeation pipe intake project,the interaction between natural riverbed sand and artificial filter layer should be considered,and artificial filter layer should be selected reasonably according to the permeability coefficient and thickness of natural riverbed sand.