Using liquefaction and consolidation processes to control soil properties

An analysis of the impact of water from streams and reservoirs on the banks of reservoirs and soil massifs of artificial embankments – dams, dikes, and embankments – was carried out. It has been determined that the main factor influencing the condition of banks and embankment soils is their saturation with water and the formation of filtration flows in soil massifs, sometimes with quite significant gradients. The main processes that determine the state of structures are the processes of loosening and liquefaction of soils and their subsequent consolidation. The processing of reservoir banks continues for periods of 5 to 10 years, while bank stabilization takes much longer – up to 30 years, and in some conditions does not stop at all. The processing of banks causes pollution of water bodies with both mineral particles and wood pulp. The nature of the locations of the reservoirs of power hydroelectric power plants and the measures taken to prepare the reservoir beds for flooding have led to the presence of a significant amount of floating wood in the reservoirs. It is noted that changes in soil properties, in particular, their bearing capacity, when saturated with water lead to non-design settlements of structures that are erected on such soils. Several examples of compaction of foundations of hydraulic structures by the flooding method are considered. Laboratory studies of the deformation of a soil embankment during the filling of a reservoir of the upper pool are described, the natural object for which was the earth dam of the Beloporozhskaya small hydroelectric power station. Filling of the upper pool of the laboratory installation led to deformation of the embankment and its breakthrough. As a result, the embankment structure settled, its soil compacted, and the backfill density increased from 0.801 g/cm³ to 1.830 g/cm³. It has been established that when an embankment is flooded, soil particles experience the action of several forces: their own weight, forces of mutual friction, buoyant Archimedes forces, and forces of hydrodynamic pressure. Under the action of the resultant of these forces, soil particles are rearranged into a denser packing, which increases the strength of the soil and its ability to withstand loads. It is recommended to use the flooding method to improve the properties of soils of embankments and foundations of hydraulic structures.