Theoretical Analysis of Bearing Capacity for Shield Tunnel Reinforcement Structure

Aimed at the bearing capacity of shield tunnel reinforcement structure, this paper conducts a series of research and theoretical derivations. First of all, the reinforced composite structure must meet some basic assumptions before any theoretical analyses. With the secondary stress analyses of the structure, the calculation method of the lag strain is derived. Adding this lag strain to the overall reinforced structure can make the strain of the whole section meet the plane hypothesis, and the overall structure can be analyzed from the strain diagram considering the lag strain. And then whether the steel bar and reinforced structure yield or not and their yielding sequence can give the shield tunnel reinforcement structure four typical failure modes under the ultimate limit state, according to which theoretical formula of the ultimate bearing capacity of various reinforced composite structure in different failure modes can be derived. At last, the result can be used to analyze the structure's ultimate bearing capacity and convergence deformation.