Analysis Of Interaction Mechanism Between Freezing Wall And Shaft Lining Based On Visco-elastic-plastic Theory

The freezing pressure of shaft wall is an importantly technical parameter of freeze sinking.It determines whether the structural design of freezing wall and shaft wall is scientific and reasonable,and relates to construction safety.Based on the engineering background of Yangcun coal mine auxiliary in Huainan,China,and combining theoreticcal calculation,field measurement and test,this paper discusses the distribution of freezing pressure.Firstly,according to interaction mechanism of surrounding soil,frozen wall and shaft lining,the analytical solution of frozen pressure under different DP criterions is obtained by using the elastic-plastic theory,and the influence of different DP criterions on frozen pressure is analyzed.The analysis results show that variation law of freezing pressure after the excavation of deep shaft lining is divided into the rapid growth stage,the slow growth stage and the stable stage.The DPI yield criterion corresponds to the maximum freezing pressure,while the DP5 yield criterion is opposite.The design safety with using DP1?DP3?DP4?DP6?DP2?DP5 yield criterion is enhanced.Secondly,based on the rheological theory of Nishihara model,this paper establishes the frozen wall-foam plate-outer shaft wall three-dimensional mechanical model,deduces visco elasticity and visco elastic plasticity calculation formula of freezing pressure,and provides theoretical support for design of outer shaft lining,and calculation method and growth law of freezing pressure.Finally,calculation parameters are obtained by experimental results.Measured values are compared with theoretical results.The results show that the theoretical formula can describe the growth regularities of freezing pressure,and prove the rationality of freezing pressure analytic solution.Meanwhile,it is concluded that there is a lag period in the growth of freezing pressure,and the freezing pressure increases with the increase of formation depth and time.The freezing pressure curves of theoretical calculation and field observing are similar.The difference between the two is that reaching the maximum value of theoretical calculation is earlier than field measured value,and the theoretical maximum of freezing pressure is slightly larger than measured value.In addition,the drawbacks of plane strain analysis are also discussed.The conclusion of this paper can be used as reference for the design and construction of freezing wall and shaft lining.