Study On Mechanics Performance Of Confined Concrete Shaft Lining With Welded Steel Fabric

In order to improve the ultimate bearing capacity of the shaft lining, and to avoid the brittle failure of the high strength concrete shaft lining, the shaft lining with welded steel fabric is proposed. Through numerical simulation and physical simulation method, the paper studies the mechanical properties of the shaft lining with welded steel fabric, and it has positive significance for the exploration and design of this structure of the shaft lining.Firstly, the stress, strain and displacement of the shaft lining with welded steel fabric are studied by the numerical simulation method, and the rule of the variation of the ultimate bearing capacity of the shaft lining with welded steel fabric with concrete compressive strength, reinforcement ratio, thickness to diameter ratio, axial pressure and steel bar arrangement is obtained. At the same time, the bearing ability and mechanical properties of the shaft lining with welded steel fabric, binding steel net concrete shaft lining and plain concrete shaft lining are compared.Secondly, physical simulation tests are carried out on the above three kinds of borehole wall structure, and the distribution law and deformation characteristics of the strain and displacement of the borehole wall are obtained. The limit bearing capacity and the ductile behavior of three kinds of wall structures are compared, and the results are compared with the numerical simulation results.Finally, numerical simulation results show that the ultimate bearing capacity of the shaft lining with welded steel fabric is 1.09 times better than that of plain concrete shaft lining, and the results obtained from this simulation are 1.19 times. At the same time, the comparison of the ductility displacement coefficient is studied by numerical simulation, and the value of the shaft lining with welded steel fabric is 0.5463, which is more than 0.5178 of the plain concrete shaft lining. Under the same confining pressure, the axial and radial displacement increase rate of the reinforced welded mesh wall is smaller than that of the plain concrete shaft lining.By comparison, the analysis of the ultimate bearing capacity, strain and displacement of the research results of numerical simulation and physical experiment simulation are quite consistent. Research shows that the ductility of the shaft lining with welded steel fabric can raise the ultimate bearing capacity of shaft lining structure, and through the results of the displacement ductility coefficient and physical tests measuring the displacement, it can be proved that welded steel fabric can improve the ductility of shaft lining well.