Fluid solid coupling analysis of hard rock wall structure in over kilometer deep shaft

Abstract

Taking the auxiliary shaft proposed by Ruihai Mining Co., Ltd. as the research object, in order to study the load law of shaft lining and ingate under high stress fluid solid coupling in deep bedrock and the influence of different permeability coefficient on the stability of shaft lining and ingate surrounding rock, Midas software was used for numerical simulation analysis, and the results show that:( 1) After the shaft excavation, the pore water pressure of surrounding rock around the shaft wall and ingate decreases gradually, which is the main permeable area. After the support, the pore water pressure is obviously raised, and the water isolation effect of the supporting layer is obvious. (2) After the shaft excavation, the area near the arc surface of shaft wall tangent to Y direction shows high compressive stress, and the maximum principal stress at - 1277.5m depth is more than 150MPa. When the polar angle increases from 0 to 180 °, the maximum principal stress increases first and then decreases. (3) After the excavation of ingate, the bottom corner and arch top are stress concentration areas before and after support. ( 4) Under the action of three different permeability coefficients, the influence of permeability coefficient on pore water pressure and maximum principal stress can be ignored after supporting measures are taken. The research results provide important theoretical basis for auxiliary shaft construction design.