Abstract:To address the deficiencies of new design methods of underground supporting structure, which lacks stability index of definite physical meanings, a study was conducted with the convergence-confinement theory. First the Kastner formula and the Duncan formula based on the Mohr-Coulomb failure criterion were selected to analyze the elastic-plastic of rock to establish ground characteristic curve. Each support unit was analyzed in series to establish the support characteristic curve of bolt-shotcrete support structure. Then, the stability coefficient of the support structure was derived in accordance with the principle of convergence-confinement and the principle of loat, which build up the quantitative evaluation of the stability of underground structure method for different stratigraphic characteristic curves. Finally, the otherness between different ground characteristic curves was demonstrated by other examples under similar conditions for rock mass mechanical parameters. Different modes of operations and operation processes were also shown.