DETERMINING LANDSLIDE SLOPE STABILITY WHEN DESIGNING A BRIDGE OVER THE RIVER POSHNARKA IN THE CHUVASH REPUBLIC

Abstract

The study is relevant due to the landsliding which lead to emergencies with the threat of building destruction, land use, and human safety. Special difficulties in the study of landslides are caused by forecasting the activation of landsliding. The aim of the study is to assess the engineering-geological and hydrogeological conditions at the site of the bridge crossing and forecast the development of the landslide process on the slopes using FEM modeling. Object of the study is the geological medium of the area of the designed bridge within the Volga upland. The paper considers the main factors influencing the development of landslide: geomorphological and tectonic conditions; lithological composition; physical and mechanical properties of soils, hydrological and hydrogeological conditions of the area. Methods: brief review of the literature; analysis of information obtained from the funds of the survey company, calculation of slope stability, modeling of the behavior of the soil massif FEM. The results. We considered the main factors of the landslide process of this territory and calculated the stability of slopes on dangerous sections by various methods. The slope is unstable in general. The simulation showed the expansion of landslide deformation zone on the left side to 107 m, on the right bank of the river to10 m from the bed with a seasonal increase in the level of groundwater. Summary. The main causes of deformation are: weakly lithified Jurassic clay, composing the entire slope; groundwater formed within the plateau and discharged into landslide accumulations, maintaining high moisture in them. It is recommended to use a layer of Permian clay deposits with high physical and mechanical characteristics as a bearing layer for bridge supports.

Keywords

• engineering and geological conditions
• regional factors
• soil
• landslide
• slope stability assessment
• simulation model