Study On Freezing Pressure Characteristics Of Deep Clay

As the depth of the new wellbore crossing the alluvium increases,problems such as freezing pipe fracture,well wall crushing and water leakage often occur in the actual project,which brings more severe challenges to the construction of the freezing and sinking method.The freezing pressure is an important parameter to ensure the safety and rationality of the design and construction of the borehole wall and the freezing wall in the freezing sinking method.Based on the engineering background of a certain mine in Huainan,this paper carries out the four parts of laboratory test,theoretical deduction,engineering field measurement and numerical simulation.Under the influence of foam board,the of freezing pressure under the interaction of outer wall and frozen wall is analyzed and studied.Through laboratory tests,the uniaxial compressive strength and elastic modulus of frozen clay have a good linear development law,and the Poisson’s ratio of frozen soil is less affected by temperature change.Permafrost creep exhibits attenuated creep at low loading stress levels and exhibits non-attenuating creep when the applied stress exceeds a certain value.Based on the viscoelastic theory,the mechanical model of the outer wall-foam board-freezing wall is established,and the viscoelastic calculation formula of the freezing pressure acting on the outer wall is derived.According to the on-site monitoring results of the freezing pressure of the auxiliary shaft of the mine,the relationship between the depth and the development law is obtained.The experimental parameters are substituted into the theoretical formula to obtain the calculated values and compared with the measured values.The law of development of the two is basically consistent,which shows that the theoretical formula can describe the law of freezing pressure more accurately,and the theoretical calculation value of freezing pressure is slightly larger than the measured value of the project,which provides guarantee for construction safety.The Flac^3D numerical simulation software was used to simulate the interaction process between the well wall and the frozen wall of the mine.Comparing it with the engineering measured curve,the trend of the two with the freezing time is basically the same,which verifies the accuracy of the numerical simulation.The research results in this paper can provide some theoretical support for the design and construction of frozen wall and shaft wall structure in similar projects in the future.Figure[34] table[16] reference[63]...