SOIL-CONCRETE FASTENING OF UNDERGROUND STRUCTURES

Abstract

The experience of using jet cementing of soils in civil, industrial and underground construction is analysed. Attention is focused on the bearing capacity and potential of using soil concrete as a fastening material (frame) of underground structures. Soil concrete fastening and a new method of its construction by jet cementing of soils along the contour of the structure are developed. This ensures a reduction in material consumption and total cost by combining the functions of temporary (enclosing) and permanent (retaining) structures. The proposed design of combined fastening: soil concrete – anchors – shotcrete. An analysis of the constructive and technological advantages of the developed fastening in comparison with common structures is conducted. In particular, the possibility of completely contouring an underground structure with a layer of soil concrete from the surface (there is no need to form and equip a pit), reducing material consumption compared to the common “wall in the soil” method (since the height of vertical wall structures is equal to the height of the structure in our case, the walls do not rise to the ground surface), and the possibility of effectively forming the thickness of the soil-cement frame while ensuring the necessary bearing capacity and water resistance were noted. A new technical idea of a borehole method of constructing underground facilities with the formation of soil concrete fastening is substantiated, which for certain engineering and geological conditions can serve as an alternative to traditional open (excavation) and mining methods of underground construction, increasing the scale of its use.