Prevention and treatment method for water inrush and sand bursting of thick surface soil thin bedrock drilling shaft

Abstract

The invention provides a prevention and treatment method for water inrush and sand bursting of a thick surface soil thin bedrock drilling shaft. The method comprises the following steps: throwing: throwing bagged stones or bricks into the shaft with water inrush and sand bursting, and throwing stone ballast with the particle size of 20-40mm into the shaft with water inrush and sand bursting when the water level rises slowly or is stable; grouting: forming a plurality of exploration injection holes in the periphery of the shaft with water inrush and sand bursting for grouting, and forming a grouting curtain; freezing: forming a plurality of freezing holes around the shaft with water inrush and sand bursting to freeze the thick surface soil thin bedrock around the shaft with water inrush andsand bursting and form a freezing wall; repairing: draining and dredging the shaft with water inrush and sand bursting, and repairing the damaged well wall; and prevention: sleeving an inner sleeve well wall in the shaft with water inrush and sand bursting. The prevention and treatment method takes repair and prevention as the principle, the aim of stability of the damaged drilling shaft for a long time is achieved, and the social and economic benefits are remarkable.

Description

technical field [0001] The invention relates to the field of mine construction, in particular to a method for preventing and controlling water inrush and sand inrush in a drilling shaft with thick topsoil and thin bedrock. Background technique [0002] The shaft shaft is the throat of coal mine production, and the safety of the shaft shaft is particularly important for the safe operation of the mine. Since 1987, there have been more than 100 mine shafts with thick topsoil in Datun, Xuzhou, Huaibei, Yanzhou, Yongxia and other mining areas in my country, and a few shafts have been damaged even before operation. Sudden serious impact on mine production, endangering personnel safety, resulting in direct economic losses of billions of dollars. [0003] Over the years, around the above-mentioned wellbore failure mechanism, relevant domestic universities and scientific research institutes have carried out a large number of theoretical analysis, experimental verification and field m...

AI Technical Summary

Problems solved by technology

In recent years, with the decrease of shallow coal resources in China, my country's coal mines have successively entered the state of deep mining, and shaft shafts need to pass through deep topsoil and thin bedrock strata, especially for drilling under the geological conditions of thick topsoil and thin bedrock Once the wellbore is disturbed by the construction of the connecting chamber group at the lower part of the thin bedrock, the bedrock stratum moves and deforms, which will lead to tensile fractures at the joints of the wellbore walls of the drilling wellbore, and water inrush and sand-flooded wells Major accident

Although this type of wellbore damage accidents rarely occur, due to the influx of a large amount of water and sand into the wellbore, it causes formation subsidence, large-scale fracture and dislocation of the wellbore, high degree of wellbore damage, and extremely difficult repair and treatment, and there is no similar technology at home and abroad. engineering for reference

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