Study On The Influence Of Freezing Pipe Deviation On Temperature Field And Freezing Pressure In Deep Shaft

In the construction of coal mine deep shaft freezing method,the phenomenon of freezing tube is more common,the collapse of the frozen tube will cause some influence on the formation of the frozen wall,and will affect the distribution of the freezing pressure in the shaft.To this end,this paper is based on the freezing of the wind shaft in Zhuji Mine,take the 320m horizon of the wellbore,according to the level of the frozen tube deflection measured data,comparison of the actual deviation of the freezing tube and no skew two cases,using the finite element program ABAQUS,the distribution of temperature field and freezing pressure of the frozen wall was studied.Mainly to the following conclusions:(1)The deflection of the freezing tube will extend the cycle time of the frozen wall to a large extent;the collapse of the tube has a great influence on the temperature and the wall thickness,without considering the freezing tube deflection,the temperature and the thickness of the frozen wall show a uniform distribution,in consideration of the case of freezing tube deflection,the temperature and the thickness of the frozen wall show a significant uneven distribution.(2)The deflection of the freezing tube affects the freezing pressure distribution of the wellbore to a large extent,without considering the freezing tube deflection,the freezing pressure of the wellbore is 1.106MPa;in consideration of the case of freezing tube deflection,the freezing pressure of the wellbore is 1.085 to 1.851MPa.(3)Numerical simulation of the freezing pressure of the borehole wall and comparison of the measured results,it is shown that the deflection of the frozen tube has a certain influence on the nonuniform distribution of the freezing pressure.The measured values of freezing pressure and numerical simulation values are different,because there are many factors that affect the freezing pressure,such as depth,soil properties,soil moisture content,construction technology,wellbore excavation,etc.,therefore,in the construction of frozen siege,the skew of the freezing tube should be strictly controlled.