机械法开挖地铁联络通道的施工力学响应分析

Analysis of Mechanical Response of Metro Connecting Channel by Mechanical Construction

为了给现场的设计施工提供参考,基于宁波市轨道交通5号线海晏北路站—民安东路站的联络通道工程,采用数值模拟方法建立三维有限元模型,研究了机械法施工对主隧道管片、主隧道螺栓接头和内支撑体系的影响。分析结果表明:主隧道管片在掘进过程中轴力最大值为858.02 kN,环向弯矩最大值为206.28 kN·m,符合安全性要求,证明了机械法施工安全可行;主隧道管片的轴力、弯矩以及内支撑体系的应力最大值出现在刀盘切削管片和第1环联络通道管节施作阶段,建议在实际施工中提高这2个阶段的监测频率,并做好应急处理预案;主隧道接头螺栓受力在掘进状态下一直呈现增长的趋势,建议采取配套的注浆加固措施,起到改善管片受力和增强接缝防水的双重作用。

In order to provide a reference for on-site design and construction, based on the connecting channel project between Haiyan North Road and Min’an East Road Station of Ningbo Rail Transit Line 5, a three-dimensional finite element model was established by numerical simulation and the impact of mechanical construction on the main tunnel segment, the main tunnel bolt joints and internal support system were studied. The results show that during the tunneling process, the maximum axial force of the main tunnel segment is 858.02 kN, and the maximum circumferential bending moment is 206.28 kN·m, which meet the safety requirements. The mechanical construction is proved to be safe and feasible;The maximum value of axial force of the main tunnel segment, the bending moment and stress of the internal support system occur in the construction stage of the cutter head cutting segment and the first ring connecting channel pipe section. It is recommended to increase the monitoring frequency of these two stages in actual construction and prepare emergency treatment plans;The force of the main tunnel joint bolts has been showing an increasing trend under the tunneling state. It is suggested to adopt matching grouting reinforcement measures to improve the force of the segments and enhance the waterproofing of the joints.