Stability of dam slopes taking into account anisotropy

Abstract

This paper presents the results of experimental studies on the deformation and strength anisotropy of gravel-pebble soils used in soil dams. During stabilometric tests, varying shear angles were obtained for stone at different orientations of soil particles in the working chamber, whether horizontal or vertical. As the hydrostatic pressure in the working chamber increased to 0.8 MPa, a reduction of shear angles of a stone by 8-12 degrees depending on the direction of layering of soil was observed. The authors compiled a calculation program called OTKOS_Ani (Delphi), which considers the strength anisotropy of pebble soils for calculating the stability of slopes of soil dams and slopes. The slope calculations were carried out for different design and height of stone and stone-soil dams, and correction factors for taking into account the strength anisotropy in slope stability calculations, kан, were obtained depending on the type, height, and density of gravel-pebble soil stacking in the dam body. The results showed that considering the anisotropy of strength properties in the calculations of slope stability of earth dams reduces the safety factors by 3-11%. This should be taken into account when selecting the design of earth dams with prisms of gravel-pebble soils.