%0 Journal Article %A LIU Xian %A YE Yu-hang %A LIU Zhen %A YANG Zhi-hao %A ZHU Yao-hong %T Experiment and Analysis on Overall Safety of Quasi-rectangular Shield Tunnel Structure %D 2017 %R %J China Journal of Highway and Transport %P 164-173 %V 30 %N 8 %X In order to investigate the overall safety of the quasi-rectangular shield tunnel structure under accidental surcharge loading conditions, full-scale load tests were conducted on lining structures with identical longitudinal joint construction but different reinforcement ratios. The actual forces acting on quasi-rectangular shield tunnel structures under accidental surcharge loading conditions were simulated by 30 concentrated loads. Whilst the failure process, the structural deformation, the joint deformation and the bolt strain of quasi-rectangular shield tunnel structures under accidental surcharge loading conditions were obtained from the tests by dint of displacement meters and resistance strain gages. The failure mechanism of quasi-rectangular shield tunnel structures under accidental surcharge loading conditions was obtained. By analyzing and comparing the results from the two tests, the effect of different reinforcement ratios on the mechanical properties of the structure was examined. Eventually, the robustness indexes of the quasi-rectangular shield tunnel structures were compared and analyzed. Whilst the overall safety was evaluated. On the basis of the analysis of robustness indexes, suggestions for the optimal design of segments were given. The results show that the longitudinal joints and the junction of the T segment and the middle column are the two weak points of the lining structure. With the same longitudinal joint construction, the increment of the reinforcement ratio only has a little effect on the performance of the longitudinal joints, and the robustness of the quasi-rectangular shield tunnel structure is not improved significantly. Structure failure is induced by local failure due to insufficient shear strength of the segment. Robustness of the structure is influenced by the absence of bearing capacity. The overall safety of the structure can be improved by raising the shear capacity of the segments. %U http://zgglxb.chd.edu.cn/EN/abstract/article_2600.shtml