Slope stability estimation of the «earth bed – road dressing» system with disturbed structure

Abstract

Off-standard soil-geological systems stability assessing issues under complex conditions is being discussed in this article. Modern methods and tools analytical review for assessing the embankment slope stability was performed here. Embankment work peculiarities in the areas of the permafrost soil spread were discussed in this paper. Special attention is paid to the embankments stability issue on a thawed foundation. The design features of the embankments on permafrost soils with the frozen soils preservation or partial thawing have been studied here. Two variations of sliding surface design-level static circuit are presented in this paper: base – earth bed and base – earth bed – road dressing. The main reasons that lead to the soil slopes stability loss of soil slopes are presented here. Based on the field research results, the embankment soil stress-related characteristics and the earth bed base were determined. Those results became the basis for embankment slope stability mathematical modeling and assessment. In software packages, GeoStab (demo) and Geo5 (educational license), based on the finite element method and the field research results, digital embankment models were built on a weak foundation. The «earth bed – road dressing» system stability calculation under the standard uniformly distributed load has been performed. Two system strengthening options are proposed to increase its stability: reinforcement with soil anchors and geosynthetic materials. The hypothesis sufficiency about the influence of the pavement road dressing state on the embankment stability was also tested here. Two models of the system and the base – earth bed – road dressing are discussed: without cracks on the track and with cracks on the track. It has been elucidated that coating imperfection affects the system stability only in the presence of medium or larger strength earthquakes. Recommendations for strengthening the embankment slopes operating in difficult soil-geological conditions were given in this article.