地铁运营下考虑隧道不均匀沉降的车-轨耦合动力研究

With the rapid development of underground railway transport, disasters caused by tunnel construction and operation have been focus. Most of the disasters are related to tunnel settlement. However, the construction and operation of the subway may result in the ground settlement especially in the cities filled with soft clay soil, which not only affects the normal use of the tunnels and surrounding buildings, but also become a threat to the security of people's lives. In this project, the present model of metro train-track coupled system will be improved by considering the elastic deformation of tunnel lining and soils. The dynamic interaction between vehicles and track systems (including monolithic bed track, elastic supporting block track and floating slab track) have been analyzed by the reverberation-ray matrix method, modal superposition method and Newmark method. The theoretical models for the three train-track systems under the nonuniform tunnel settlement and the track irregularity are established. Considering various train speeds, the vehicle-track vibrations under tunnel settlement are studied and the dynamic amplification factor is extracted. At the meantime, the in-site experiment will be carried out and the accelerations so obtained are to be compared with theoretical ones. The structural dynamic indicators and subway settlement standards for various train speeds will also be concluded in this project, as well as the suggestions for optimization design of the track systems. It is hoped that the present research can be applied for the design of subway track system and can be a theoretical guidance for the traffic safety.

随着地铁交通的快速发展，地铁建设与运营引起的灾害已成为关注的热点，很多灾害都与地铁的沉降有关，在大面积软粘土地区，地铁的施工和运营均可能产生隧道不均匀沉降，会影响隧道和周边建筑的正常使用，甚至影响人们的生命安全。本项目将改进现有的列车车辆-轨道分析模型，利用回传射线矩阵法等研究三类常用地铁轨道结构（轨枕埋入式整体道床轨道、弹性支承块轨道和钢弹簧浮置板轨道）与车辆的耦合动力性能；建立考虑隧道不均匀沉降的三类地铁轨道结构的分析模型，研究沉降分布参数对车轨动力性能的影响，提取不均匀沉降对于地铁车-轨的动力放大因子；选择地铁平顺区段和沉降区段进行现场动力测试，得到行车条件下的轨道动力响应，以验证和修正理论模型。通过研究，提出隧道不均匀沉降的结构动力学控制指标，以及不同行车速度下不均匀沉降的控制标准，并通过参数分析提出轨道的优化设计方案，为降低维护成本、保障通车安全、指导轨道结构选型提供理论支持。

随着地铁建设热潮的兴起，大面积软粘土分布地区的地铁施工和运营安全越来越受到大家的重视。本项目结合理论研究、室内实验和现场实测，分析了软土地区隧道不均匀沉降对车轨性能和运营安全的影响，并研究了隧道施工和运营情况下饱和软黏土的动力性能。具体包括：对轨枕埋入式整体道床轨道、弹性支承块轨道、钢弹簧浮置板轨道等三类轨道，分别建立了车辆-轨道-衬砌-土体系统动力学分析模型，基于回传射线矩阵法得到整体轨道的自振频率和模态，引进梁板理论改进短板型浮置板轨道的计算精度，并提出土体和隧道衬砌的合理刚度取值标准；建立了隧道不均匀沉降下地铁列车与三类常见轨道结构的耦合分析模型，通过参数分析得到不均匀沉降分布形式、地铁运营速度、轨道元件参数等因素对于地铁车轨动力性能的影响，并提出了不同车速下的不均匀沉降控制标准，通过参数分析得到轨道的优化设计方案；设计并进行地铁现场实测，将理论结果与实测结果进行对比验证；此外，研究得到了地铁下卧土层在列车荷载作用下的动力性能及长期沉降规律，建立了土体动刚度、孔压和动应力模型，并分析得到了新建盾构隧道对邻近已建隧道变形的影响等。本项目的研究成果可为地铁隧道的安全行车、轨道设计选型等提供理论依据，尤其对具有大面积软土地基分布的南方地区具有较大意义。

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