Influence of salt in site soils on permeability and pore diameter

In order to explore the influence of salt content on permeability in site soils, based on the laboratory water saturated permeability test, with the addition of two soluble salts with the gradient of 0.2%(mass fraction) of NaCl and Na2SO4in the desalination soil, the change of permeability coefficient in the soils with particular content and category saline was tested. At the same time, the internal pore structure of salt samples by mercury injection test was tested in order to conform the results of permeability test from the microscopic. The results show that the permeability coefficient of salt samples decreases with the increase of salt content and the both accord with good negative exponential correlation. The pore size distribution curve of salt samples gradually shifted to the left with the increase of salt content. The peaks of the pore size distribution curve present the form of index decreasing with the increase of salt content, corresponding to penetration test results. The internal pore structure of salt samples is directly related to its permeability, and the existence of salt has the effect of a certain degree of congestion and filling to the internal pore structure, affecting the permeability of soils. © 2016, Central South University Press. All right reserved.