Study On Freezing Optimization And Temperature Field Of New Auxiliary Shaft In Qianyingzi Coal Mine

Artificial freezing method is widely used in coal mine shaft construction because of its advantages of good controllability,strong applicability and green environmental protection.In the wake of the uninterrupted exploration of coal resources,the coal reserves contained in the shallow strata can not satisfied the demand of people's production and life,and people begin to turn their attention to the deeper coal resources,Therefore,the shaft of coal mine construction is getting deeper and deeper.Due to the differences of geological conditions and freezing time,the contradiction between freezing engineering and excavation and masonry engineering is becoming more and more intense.The deeper the shaft is,the more complex the formation conditions are.In recent years,coal mine safety accidents are more and more frequent.Therefore,It is of great significance in the freezing scheme is optimized to reduce the contradiction between freezing and excavation and masonry,and shaft construction to strengthen the monitoring of freezing temperature field and predict the development of freezing temperature field more accurately.In this paper,based on the initial freezing scheme designed according to relevant specifications,the freezing scheme is optimized by changing the layout of freezing holes.The original double circle hole layout of main row hole+auxiliary hole is optimized to three circle hole layout of main row hole+auxiliary hole+anti sheet hole.The feasibility of the optimum proposal is verified by ANSYS finite element numerical simulation software,The results show that:after the optimization of freezing proposal,the intersection time of freezing wall in shallow stratum is about 2 days earlier,the temperature of shaft side drops faster,and the time of frozen soil extending to shaft side is much earlier than that before optimization,It greatly eases the contradiction between freezing and excavation.Two methods,ANSYS finite element numerical simulation and visual network monitoring platform,are used to monitor the freezing temperature field.The two methods have their own advantages in use.Thanks to the current developed network,the visual network monitoring platform is more convenient and faster.Although the ANSYS finite element numerical simulation process is cumbersome,the analog results are closer to the result of actual measurement,The analog results of the two methods are contrast with the field reality measured data:the two methods are consistent with the engineering practice in the circle time of shaft freezing wall,and lower in the average temperature of freezing wall and shaft side temperature.The effective thickness of freezing wall simulated by the visual network monitoring platform is thicker than that simulated by the finite element numerical simulation.Figure[57]table[14]reference[88]...