The porosity determination of dispersion medium by the method of expansion of pore air into vacuum (on the example of the main soil types in the Chuvash republic)

Abstract

Recently, for the study of the hydrophysical properties of finely dispersed systems, such as soils in Russia and abroad, tomographic studies are beginning to be widely used. The main lack of their use is a significant cost, the lack of the ability to conduct measurements directly in the field. Therefore, we have developed a fairly simple and accessible method for calculating the porosity, based on measuring the state of air both when the pore air expands into the region with a reduced pressure, and when air is pumped from the region of increased pressure. The method makes it possible to take into account the presence of pores covered by menisci and dead-end pores. Statistical processing of experimental results shows the identity of porosity values, with a confidence probability of more than 95 %. However, the relative measurement error is approximately half of that for the case of air injection. On the cultivated lands, after the passage of machine-tractor units, the appearance of a compacted soil layer often occurs. The study of the dynamics of deformations accumulation in the soil is conveniently investigated using maps with isolines of the soil porosity values. They can be used for economically justified planning of agricultural activities. The developed express method for determination of porosity, due to the speed and simplicity of measurements, makes it possible to obtain a large amount of the data in a short time.