类矩形盾构隧道结构极限承载力分析

Ultimate Bearing Capacity Analysis of Quasi-rectangular Shield Tunnel Structure

摘要:

建立考虑材料非线性与几何非线性的类矩形盾构隧道结构受力非线性数值模型。利用该模型对极限工况下的三组试验结构进行数值模拟，并将数值模拟结果与整环足尺试验结果进行对比，验证该模型的正确性和有效性。最后，对影响类矩形盾构隧道结构受力性能和极限承载力的关键因素进行参数分析。结果表明：类矩形盾构隧道结构破坏源于管片接头破坏，最终因T块管片破坏导致结构失去承载力，结构破坏模式与纵向接头、管片本体及中柱的力学性能相关；类矩形盾构隧道结构理想的破坏模式是在管片接头充分发挥承载力的同时，管片本体主筋屈服、结构发生延性破坏。

Abstract:

In this paper,a nonlinear numerical model of bearing capacity for quasi-rectangular shield tunnel structure is established. In the model, the material nonlinearity, the geometric nonlinearity are all taken into consideration. Three groups of test structrures under limit working condition are simulated numerically. The results of the numerical simulation and full-scale ring tests are compared to verify the correctness and effectiveness of the model. Then the key parameters are analyzed to investigate the mechanical behavior of the structure. The results show that the failure of the structure originates from the failure of longitudinal joints,and eventually the structrure reaches the ultimate bearing capacity due to the failure of T block. According to the numerical analysis, the structural failure mode is related to the mechanical properties of longitudinal joints, segments and interior column. The ideal failure mode of the structure is that the bearing capacity of longitudinal joints is fully utilized, while the reinforcement of segment is yielded which leads to the ductile failure mode of the structure.