Choosing injectable solution for auger technology of underground space protection against pollution

Abstract

Purpose. The research is devoted to the experimental choice of injection composition for auger technology of installation of underground anti-filtration shields under the source of pollution. Auger technology for the arrangement of anti-filtration shield consists of pilot holes made by the horizontal directional drilling, which is followed by the arrangement of a waterproof layer by replacing the soil with auger by special concrete solution. Methodology. The main research method is experimental-statistical modeling, which includes: conducting laboratory tests; correlation-regression analysis of the obtained data; qualitative, quantitative and graphical analysis of the obtained regularities of the studied indicators change from the varied factors. Findings. The main results of the study are the following: substantiation of the relevance of the development of auger technology for the protection of underground space; development of methods and conducting laboratory experiments on the injectable solution choice; analysis of experimental and statistical regularities of changes in water absorption and time of plastic strength setting when varying the composition of the anti-filtration shield (concentration of fiber, bentonite, water glass); development of the concept of technology of the anti-filtration shield arrangement. Originality. Experimental studies made it possible to establish that the minimum water absorption of the shied samples is observed at the lowest concentration of fiber (0.5 %), bentonite (1 %) and liquid glass (2 %) in the injected solution. For structures of small width (10-20 m.), there are suitable compositions with a minimum time of plastic strength setting at a concentration of fiber (3 %), bentonite (5 %) and water glass (18 %). For structures with a large width (40-60 m.), there are suitable compositions with a long time of plastic strength at a concentration of fiber (9 %), bentonite (5 %) and water glass (6 %). Practical value. Experimental results made it possible to develop technological recommendations for the construction of anti-filtration shields using auger technology. Namely: to develop a concept and procedure of works, to calculate the costs of labor and machine time, to compile a list of necessary materials, machinery and equipment.