盾构管片接头简化数值模拟方法

由管片组装的盾构隧道衬砌环刚度分布不均，其薄弱环节为管片接头处。管片接头刚度的合理确定对于盾构隧道施工全过程模拟的合理性、地表沉降槽的确定以及土体损失的准确估算至关重要。根据管片接头受力特点及其构造，考虑对管片接头及其附近区域进行刚度修正，而管片其余区域保持原刚度不变，提出管片接头简化数值模拟方法——局部刚度修正法。基于圣维南原理和变刚度梁理论，推导了确定接头刚度的公式，并给出了相关参数的确定方法。结合室内盾构管片接头足尺试验成果，对不同荷载作用下管片接头的变形情况进行了数值模拟及对比分析。研究成果为盾构三维施工全过程的精细化数值模拟分析奠定了基础。

Simplified numerical simulation method for segment joints of shield tunnels

The distribution of the lining stiffness of shield tunnels is uneven for the lining structure composed of several segments and joints, and the weak links are at the segment joints. The correct determination of the segment joint stiffness is crucial for the simulation of construction process of the shield tunnels, the determination of the surface settlement trough and the accurate estimation of ground loss. A simplified method, district modified stiffness method (DMSM), is proposed for simulating segment joints based on the stress and structure of segment joints, which corrects the stiffness at the place of joints and the nearby areas and maintains the stiffness of the rest segment regions. A formula for determing the segment joint stiffness is deduced, and a method for determing the relevant parameters is proposed based on the Saint-Venant principle and the variable stiffness beam theory. The numerical simulation and comparable analysis of deformations of segment joints caused by positive and negative bending moments are performed based on laboratory full-scale tests on segment joints. The results show that the proposed method can simulate the mechanical behaviors of the segment joint well, and is helpful for refined three-dimensional analysis of construction process of the shield tunnels.