The Analysis Of Shaft Lining Stability Considering The Influence Of The Unfreeze Of Air Shaft Frozen Wall In Xinzhuang Coal Mine

With the deep mining of coal resource in China, the shaft needs to through the deep rock-soil layer. Especially in the western region, the majority of the shaft need to through the soft rock geologic strata of rich water of the Jurassic and Cretaceous. Shaft sinking by freezing method became one of the most effective methods. There are differences in freeze design parameters with vertical shaft which has deep alluvium of the eastern region. So it has important significance to research the stability between frozen wall and shaft lining in the western areas.We regard the frozen shaft with the deep of 910 m of xinzhuang,Gansu province as the engineering background. It shows the changing of sandstone mechanical parameters under the effect of low temperature of cretaceous through the laboratory test. It is concluded the calculation formula of freezing pressure and displacement of sidewall by modelling the elasto-plastic deformation between frozen wall and shaft lining based on the combination of frozen wall and surrounding soft soil. The numerical calculation results and the theoretical calculation results are consistent through analyzing the radial deformation of frozen wall by the finite element software. Consider the effect of temperature change on frozen soft rock mechanical parameters at stage of frozen wall. According to the results of laboratory test, measure the force of the interaction of the shaft lining and the frozen wall in the process of thawing the frozen wall at different temperature. Then we can get the analytical solution of sidewall stress in theory, and predict the dangerous layer position. Consider the influence of temperature stress for the shaft lining after thawed frozen wall. Derived the stress component between alluvium and bedrock section, and prove that it is satisfied with the requirement of strength and stability in xinzhuang after thawed frozen wall. Using the finite element simulation software ANSYS to analyze the sidewall stress of the frozen wall under different temperature. And analysis the stress and deformation on numeric of the frozen wall while thawing process. Finally we will get the trend of the frozen pressure,which is in conformity with the theoretical calculation results.