Study On Defrostation Of Frozen Wall In A Vertical Shaft With Ventilation

In recent years,the deth of mine construction is getting deeper and deeper,and the strata are also becoming more and more complicated.Freezing method becomes the preferred construction method for shaft construction under complex conditions.Shandong Wanfu coal mine,which is currently under construction,is to use the freezing method to successfully complete the construction of three shafts.Based on the main shaft of Wanfu coal mine,the thawing rule of the frozen wall under the ventilation condition is studied.In this paper,the factors that affect the thawing of the frozen wall are ventilation temperature,relative humidity,speed,soil property,initial temperature and the depth of the ventilation.Through numerical simulation and physical experiment,the temperature field changes in freezing wall are studied.The cold quantity supplied in the underground was provided under typical parameters during the 800 days of ventilation by numerical calculation,and the development of temperature field of well wall and frozen wall throughout the ventilation process was also provided.Through the single factor test and multi-factor orthogonal experiment,the influence of the various factors on the freezing wall thaw and its significance are obtained.The results of the physical experiment are compared with the numerical simulation results,and the accuracy and reliability of the two methods are verified.The results of this paper can provide theoretical basis for the grouting at the end of frozen wall melt and the cold energy utilization.