Study on mechanism and application of water injection to prevent shaft failure

Water injection is an emerging method to prevent shaft failure in recent years. It is to prevent shaft failure by maintaining the stability of the water level at the bottom of the thick alluvium from the perspective of controlling aquifer dewatering. In view of the problems of insufficient understanding of the mechanism of water injection to prevent shaft failure, the field application effect and feasibility also require systematic research and discussion, the laboratory test, numerical simulation and field application were used to analyze the engineering properties and deformation mechanism of deep-buried clay under the condition of dewatering in Huang-huai region. The mechanism of water deformation was studied under the conditions of sparse and water injection and the deformation of the shaft. The effect and feasibility of water injection were also discussed. The results showed that the deep-buried clay is mainly composed of expansive materials such as illite and kaolinite, and it changes to a semi-solid state as the burial depth increases. The deformation of the overlying soil layer of the aquifer sand layer at the bottom of alluvium is mainly slippage.The stress on the shaft wall and the formation deformation under the condition of dewatering and water injection was studied. It was concluded that under the hydrophobic condition, the vertical compressive stress on the shaft wall continues to increase, and the formation compression increases. However, after water injection, the vertical compressive stress on the shaft wall decreases, and the formation compression decreases or even slightly lifts, indicating that water injection effectively suppresses the generation of additional stress and alleviates the stress state of the shaft wall. On this basis, through the application effect of the water injection method in the Jining No. 3 Coal Mine and the feasibility analysis of the application of the water injection method under the condition of large drawdown and drainage in the Zhuxianzhuang Coal Mine, it was concluded that the loose bottom aquifer in the industrial square in the Jinning No. 3 Coal Mine has strong controllability and the on-site porous joint water injection has a good effect and effectively prevents shaft destruction. The control of water injection in Zhuxianzhuang Coal Mine was poor, and under the conditions of large drawdown and drainage, it was not appropriate to use water injection method to prevent shaft failure. The research results further reveal the mechanism of water injection to prevent shaft failure, and provide a theoretical basis and application reference for the prevention and control of similar shaft failure.