Comparison of test results to determine the parameters of soil strength to ensure the stability of earth slopes

The content of large soil fractions in soils complicates the experimental part of the research, but, the modeling method makes it possible to determine the effect of soil filler on slope stability. The article presents the results of experimental study of the strength of coarse-clastic soils with different percentages of large fractions of gravelly soil (up to 20 mm) and aggregate (up to 5 mm) in the study of slope stability. The studies were carried out on three types of experimental equipment, which confirms the reliability of the results obtained. Recommendations are given for applying the values of the strength characteristics of coarse-grained soils in calculating the stability of slopes. The results of the tests are carried out in a tray and shear testing devices. Mixture of soil fractions from 2 mm to 50 mm. Purpose of the tests is to determine the actual parameters of soil strength j and C, taking into account the effect of impurities on the stability of slopes. Reliability of the results confirmed the comparability of the results of previous tests. Tray allows for testing models of slopes composed of mixtures of sand fractions from 2 mm to 20 mm. Model sizes slopes are defined relative to the size tray. Tray dimensions ‑ length 1400 mm, width 500 mm, height 1000 mm. The design of the shear device allows to investigate coarse soils of different factions. The diameter of the fractions were tested for shear device area of 100 sm2 is from 2 mm to 20 mm. The diameter of the fractions were tested for shear device area of 1000 sm2 ‑ from 5 mm to 50 mm. The experiments were performed in the laboratory "Geotechnics in Construction" in KazGASA