Mechanical And Numerical Analysis Of Vertical Shaft For Freezing Construction

Vertical shaft construction was one of the main linkage projects of mine construction, vertical shaft was critical project for the whole mine construction, its good or bad of design and construction quality was closely associated with mine construction and production time. Freezing construction for vertical shaft in Kekegai Mine was taken as background, )lastoelasticity mechanical analysis for vertical shaft mechanical model was done, mechanical characteristics variation of rock mass after freezing was focused on analysis. Mechanical parameters treated by engineering method was used in FLAC3D software, shaft lining displacement and radial stress of vertical shaft with different freezing holes was analyzed through numerical simulation. Combined shaft lining displacement of vertical shaft and spends of freezing hole construction, the main tasks were as follows:1) Based on elasticity hypothesis, mechanical problem of vertical shaft was simplified, mechanical and displacement characteristics based on lasticity hypothesis was analyzed. Shaft lining displacement changing rend with different frozen thickness was analyzed, which provided heoretical basis for numerical simulation.2) Drilling holes were drilled near vertical shaft, hydrogeology condition of rock mass was obtained; Different temperatures in different lepth formation were obtained, the variation trend with increase of formation depth was analyzed; water-bearing of different deformation was letected, horizontal narrow and long corridor method was adopted to calculate the inflow of water in vertical shaft, which provided basis for ascertaining freezing construction method of vertical shaft.3) Related mechanical experiments of rock specimens were conducted, mechanical parameters after and before freezing rock specimens were measured, the main parameters included axial compressive strength, tensilestrength, cohesion, friction and density and so forth were measured. Mechanical parameters of rock specimens were transformed into parameters of numerical simulation, which provided parameters for numerical simulation.4) Adopted mechanical parameters transformed by engineering method, freezing thickness with different freezing holes were calculated, numerical simulation model with different freezing thickness were established. Number of freezing holes was ascertained with consideration of maximum displacement of vertical shaft lining and construction spend of freezing holes.5) Through numerical simulation for pore pressure of shaft wall under different excavation depth by using of FLAC3D software, which is conducive to verifying rationality of adopting to construct shaft in water aquifer.