盾构隧道管片接头抗弯承载力计算模型研究

盾构隧道管片接头承载力的计算是管片设计和服役性能评估的重要部分和关键部分，针对形式相同而细部构造不同的管片接头，提出一套适用于其抗弯承载力计算的理论方法十分重要。鉴于此，文章基于接缝面的不连续特征将接缝面进行适当分区，建立盾构隧道管片接头抗弯承载力计算模型，并给出对应的求解算法。将理论模型的计算结果与接头足尺试验结果进行对比分析，验证理论模型的正确性，然后采用该计算模型对管片接头抗弯承载力进行分析与讨论。结果表明：管片接头抗弯承载力曲线具有明显的非线性特征，随着轴力的增大，接头极限弯矩呈先增大后减小的趋势。混凝土强度对于接头抗弯承载力的影响较为显著，而螺栓强度和螺栓直径对于接头抗弯承载力的影响程度受轴力控制，轴力较小时，上述两参数的增大对于接头抗弯承载力的提升效果明显，轴力较大时效果逐渐减弱，当轴力高于某一阈值后，螺栓对于接头抗弯承载力无影响。文章所提出的抗弯承载力计算模型与研究结果以期为盾构隧道结构设计、试验和性能评估提供重要参考。

A calculation model of flexural bearing capacity of segmental joint for shield tunnels

 The calculation of the bearing capacity of segmental joints of shield tunnel is an important and key part of segment design and its service performance evaluation，and it is necessary to propose the calculation methods for segmental joints with the same form and different detailed structuresIn this work，the imperfection of the joint surface is considered and the joint surface is properly partitioned，and then a mechanical model for the calculation of bearing capacity of segmental joints is established and corresponding solution algorithm is designedThe full scale joint tests are carried out to verify the correctness of the theoretical model，and the joint test results are in good agreement with the analytical results，indicating that the model is valid and has high calculation accuracyFurthermore，the bearing capacity of segmental joints is analyzed and discussed by using the calculation modelThe results show that the joint bearing capacity curve has obvious nonlinear characteristics，and as the axial force increases，the ultimate bending moment of the joint increases firstly and then decreasesThe influence of concrete strength on the bearing capacity of the joint is significant，and the influence degrees of the bolt strength and bolt diameter on the bearing capacity of the joint depend on the magnitude of the axial forceWhen the axial force is small，the increases in the above two parameters significantly improve the bearing capacity，but as the axial force increases，the improvement effect gradually diminishesThe mechanical model and related results can provide important references for the design，test，and performance evaluation of shield tunnels.