Finite Element Analysis Of Creep Deformation Of Frozen Wall In Deep Thick Water-rich Bedrocks

With the deep development of coal resources exploitation gradually, shaft well, more andmore across the deep and thick water-rich strata especially the Jurassic and Cretaceous stratain the west.These soft rock have low intensity and rheological property. But studies on thephysical and mechanical properties under low temperature, frozen wall temperature fieldcharacteristics and deformation characteristics of these strata is still in the exploratory stage.Based on Hujiahe coal mine soft rock shaft frozen engineering. By the theoretical analyticalcalculation and finite element numerical simulation method, the deep rich water rockrheological deformation of frozen wall is studied.On the basis of system analysis about rock rheological constitutive model, combinedwith the frozen rock characteristics of Hujiahe coal mine, choose the Nishihara model tostudy the creep deformation analysis，and use the displacement reverse analysis method to getrheological parameters of the Nishihara model.Based on infinite thick-walled cylinder theory,establish the axisymmetric plane strain deformation analysis mechanical model of frozenwall,get the analytical solution of radial displacement of the frozen wall inside and outsideboundary under elastic, elastic-plastic and viscoelastic plastic state. Use the ANSYS finiteelement analysis method to establish frozen wall elastic plastic and viscoelastic plastic3Dfinite element model, simulation calculation the deformation characteristics of frozen wall, theresult shows that the creep deformation of frozen wall in deep thick water-rich bedrocksaccounts for larger proportion in total deformation.So,creep deformation can not be ignored;Use ANSYS software to analyse the deformation characteristic of frozen wall in deep thickwater-rich bedrocks under the condition that rock’s rheological characteristic be considered,get the distribution law of radial displacement, total strain and creep of the frozen wall alongthe height of excavation section and the thickness of frozen wall, get the radial displacement and creep change law with time, get the influence law of frozen wall deformation underdifferent formation lithology and thickness of frozen wall and the height of excavationsection.In this paper, through numerical simulation method to obtain the rich deep bedrock waterbasic rheological deformation law of frozen wall.These achievement has certain referencesignificance for the frozen wall design and construction in similar strata.