Stress Calculation for a Double Layer Shaft in Special Strata

A stress calculation method has been established for the double layer shaft in special strata. After some simplifications of the mechanical model, the problem was broke down into three subproblems, and a Saint-Venant solution was obtained by solving and adding up each subproblem. An example for certain double layer shaft was presented, and the stress results were compared with the single layer shaft under the same conditions. The fourth strength theory was applied to study the safety of the shafts, and the results show that, the safety for the inner layer of the double layer shaft is better than the single layer shaft, while the safety of the outer layer is relatively worse. We indicate that the application of this double layer shaft is advantageous for the safety production of the mine, and the outer layer of this shaft is the fragile area that needs to be repaired primarily.