MODERN APPROACHES TO THE QUANTITATIVE ASSESSMENT OF SLOPE STABILITY UNDER SEISMIC CONDITIONS

Abstract

An analysis of the slopes stability, composed of argillites, with possible seismic impact was carried out for the section of the Northern slope of the Aibga ridge (Krasnaya Polyana). With the help of ArcGIS for the area under consideration, the spatial variability of slope angle was studied and its influence on the variability of the values of the factors of safety (FOS) was assessment. An analysis was also made of the influence of the strength characteristics of argillites on the variability of the values of FOS. Seismic impact in the quantitative assessment of slope stability was assessed using pseudostatic and dynamic analyzes. For the dynamic analysis, the Newmark method was applied. A comparative analysis of the values of the minimum, average, and reduced FOS obtained during dynamic analysis is performed. To compare the values of the safety factors obtained in various methods of dynamic analysis of slope stability, the 0.65-method proposed inChina(H. Liu) was used. It is shown that the calculated values of the minimum and average safety factors obtained during the dynamic analysis do not reflect the state of the slope under seismic action. Quantitative assessment of the slopes stability taking into account the seismic effect obtained by dynamic analysis using the 0.65-method are comparable with the results of stability assessment obtained using pseudostatic analysis and are more realistic. The results of a quantitative assessment of the slope stability showed that the strength characteristics of argillites have a direct effect on the calculated values of the safety factor. It was found that slopes of more than 40° steepness, composed of argillites with low cohesion values (<20 kPa), under the seismic action of 8 points pass into an unstable state.