The streambed sediment grain size analysis and empirical formula of vertical hydraulic conductivity of Wei River

This paper is mainly talk about the relationship between grain size distribution and the vertical hydraulic conductivity of streambed sediment. The field tests and samples collection are conducted in Xianyang and Xingping segments of Wei River which located in Shaanxi province, China. The field tests adopted the falling-head standpipe permeameter test which is very suitable for measuring streambed sediment hydraulic conductivity; the result would be compare with the values of grain size analysis. At first five empirical formulas were used to estimate the value of vertical hydraulic conductivity, however, the result is far from the result of field tests. Then on the basic of Kozeny-Carman formula, matching with the field measured values obtain a new empirical formula.