Geological conditions of suffosion processes development and their acitivity at Sal-Don neotectonic upland (Rostov NPP area)

Abstract

Suffusion processes and their influence on the stability of the Rostov NPP site are investigated. Geological, tectonic, geomorphological, hydrogeological conditions, as well as anthropogenic factors affect the development and intensification of suffusion. These conditions and factors include the following: predominance of Pliocene and Quaternary sands in the geological cross-section; the presence of clay aquiclude underlying sandy deposits; natural seasonal and human-induced fluctuations of the water level in the Tsimlyansk reservoir; as well as pumping of groundwater. The buried relief in the shape of a slope dissected by erosional gullies are also of great importance. These erosional depressions are probably channels, along which sand is removed to the Tsimlyansk water reservoir. It is suffusion that may be the reason of surface subsidence that causes deformation of ground basements and inclinations of some engineering structures at NPP. Recent tectonic conditions control the formation of active zones and fracturing in the mantle deposits favoring percolation of surface water. Suffusion amplified by tectonic and technogenic factors results in the subsidence of soil basement in some places at the NPP site, displacement of reference marks, and inclination of engineering structures.