The solution of landslide problems in the Saratov region

Abstract

They are presented data on the development of landslide processes in the Saratov region, the territory of which is one of the most landslide hazardous due to geological, tectonic and hydrogeological conditions, deep rugged terrain, active erosion, climatic features and anthropogenic factors. The directions of solving the problem of reducing the negative impact of landslides on the condition of territories are shown, the main of which are identification and assessment of the threat, stabilization and retention of the landslide massif. The landslide hazard is determined on the basis of geotechnical, geodetic, hydrogeological, hydrological surveys, weather observations, monitoring and modeling of the landslide process. To stabilize the landslide, its body is drained using a surface runoff system and deep drainage. Then the landslide surface is level off or cut into blocks, ground properties are changed. To hold the landslide massif, retaining walls are used. The results of monitoring the development of a landslide in the October gorge of the city of Saratov, which was formed on the left steep side of the gorge between the equipped spring and the 110 kV transmission line, are presented. Its width along the front reaches 200 m, length 150 m, landslide body area 25-30 thousand m2, total weight about 0.5 million tons. The landslide is closely related to the areas of groundwater outlet, including the Oktyabrsky spring. The calculated strength characteristics of soils in the displacement zone were obtained: on contact with calcareous loams, the angle of internal friction is 36°, specific adhesion is 0.05 t/m2; landslide body density 1.62 g/cm3; on contact with clay, respectively, 10°, 2.5 t/m2 and 1.62 g/cm3. Based on them, the stability indices of the landslide slope and landslide pressure for the zone of active landslide deformations are determined. The safety factor for the calculated transections was 0.99-1.0 in the natural state and 1.05-1.43 with design measures; design landslide pressure 45 tf/m. A system of anti-landslide measures is proposed. It includes the installation of retaining structures from bored piles with grillage and retaining wall; slope profiling with the construction of a counter-banquet; the device of the surface drainage system with the discharge of water into the roadside tray; landscaping of slopes by sowing herbs.