Ensuring the sustainability of the motorway subgrade in the zones of underground mining operations

Abstract

The article describes a variational method for calculating the motorway subgrade stability. The application of this method allows to quickly and accurately determine the most dangerous sliding surface with a minimum coefficient of stability. The purpose of the article is to improve the variational method for calculating the motorway subgrade stability. The article proposes to apply this method in the calculation of the transport earthwork structures, located in the area of mining operations, where there is a danger of failed subsidence. Underground mining operations have a significant impact on the vertical bent curves of a motorway, that leads to the modification of the subgrade geometric dimensions in the negative direction. This is the cause of sharp fluctuations in the values of local curvature and the radii of vertical curves. The use of variational method for calculating the motorway subgrade stability will allow to take into account the velocity of the saturated soil mass movement and the change in the geometric parameters caused by the underground mining operations. The advantages of this method include the possibility to consider the efforts from geosynthetic materials, recommended to use for strengthening the basement and slopes of the subgrade, the rheological properties of the soil, and the load from the vehicle moving along the surface. In the process of research, regulatory documents on the calculation of the stability of road structures reinforced with geosynthetic materials were studied. The identified shortcomings of the existing regulatory documents allowed to conclude that it is necessary to consider the velocity of the saturated soil mass movement caused by the underground mining operations when calculating the stability coefficient of soil structures.