Assessment of operating environment of concrete lining of sewage collector tunnels

Abstract

Abstract The most important task in the field of design and construction of urban underground structures is the durability of their lining, which is a failure-free operation of the structure for a given period at a minimum cost of its construction. The quality of building processes, service life of underground structures and capital costs depend on the type of lining and technology of its construction. In this paper, on the basis of collector tunnels examinations the conditions of their work were revealed. Studies showed that the failure of the lining of sewers or its partial destruction occurs under the influence of the following factors: water-abrasive wear of the tunnel tray; gas and chemical corrosion, caused by the aggressiveness of the media flowing through the tunnels; biological corrosion; leaching of free lime from concrete under the influence of external groundwater, etc. It is revealed that the collector tunnels are subject to erosion of the tray associated with the abrasion effect of solids characteristic of the masses flowing through the tunnel. The effect of abrasives is exacerbated by the presence of “fistula”, cracks and chemical effects, which leads to weakening of the material and the tray design.