Substantiation of the Method for Calculating Soil Deformation Modulus

Abstract

The purpose of the article is to analyze methods for calculating the deformation modulus of subgrade soils based on the results of stamp tests. To perform a comparative analysis, stamp tests of a subgrade model built in a soil channel were carried out. During the tests, the load was applied in steps, and the stamp settlement was measured upon completion of deformation stabilization from each step. The criterion for the stabilization of deformation was a decrease in the speed to 0,02 mm/min and the time of application of the load, which should be not less than 120 s. Further, the calculations of the soil deformation modulus were carried out using various methods regulated by the standards of the Russian Federation. The results of calculating the deformation modulus are grouped into data samples, which are processed by methods of mathematical statistics. During data processing, each sample is checked for gross errors. The data samples were checked for belonging to the same general population. To check whether three samples belong to one general population, the Kruskal W.H. and Wallis W.A. criterion was applied. Based on this comparison, we obtained judgments about the significance of the differences in the samples. As a result, to determine the deformation modulus of soil and road pavements made of granular materials, a way for calculating the deformation modulus by a method that assumes a non-linear dependence of deformations from pressures described by a polynomial of the second degree is recommended.