地铁移动荷载作用下软土的软化机理与长期沉降预测技术研究

Metro service has many advantages, such as, big transportation amount, quick, punctuality and environmental protection, etc. However, the long-term settlement and different settlement of soft soil foundation of both metro-stations of subway bring some risks and damages for the metro safety service. The settlement trough of ground surface will be widening as developing of long-term settlement of subway. So far, the adaptive prediction model of long-term settlement of subway has not been developed for the metro long-term service. In order to realize the objective, soften mechanism and long-term settlement feature of soft clay soil under metro moving cyclic load have to be studied. Therefore, the project will be undertaken four aspects research work, ①The test study of soften mechanism of soft soil under moving load will be carried out; ②The change rule of long-term settlement of the metro foundation of soft clay soils will be studied; ③ The wheel/rail-ballast-soft soil coupling model and calculation method of long-term settlement of subway will be set up. ④ The prediction technology of small sample intellectual theory will performed for the long-term settlement of subway.

地铁具有运量大、快速、准时、环保等优点，但地铁运营过程中地铁区间道床软土地基的长期沉降和差异沉降给地铁的安全运营带来威胁和危害，伴随着长期沉降的发展，地面沉降槽也随之不断地发展或增加，但到目前为止，尚未建立符合地铁实际运营条件的地铁移动重复荷载作用下软土长期累计变形的计算模型。为实现这一目的，需要研究移动荷载反复作用下土层的软化机理和长期累计变形的变化规律，为此，本课题将开展这几方面的研究工作：①地铁移动荷载作用下软土软化机理的试验模拟研究；②地铁隧道下卧软土地基的长期沉降变化规律研究；③建立稳健的机车轮轨-道床-软土地基的耦合模型和长期沉降计算方法；④地铁长期沉降预测小样本智能预测技术研究。

城市交通拥堵、机动车大量排放尾气引发环境问题，已成为一种“城市病”，仅仅依靠地面交通规划根本无法解决交通拥堵与尾气排放问题。针对这些现状国家提出要大力发展公共交通，尤其是发展城市轨道交通，如地铁、轻轨等，来解决城市拥堵与尾气污染的“城市病”。地铁具有运量大、快速、准时、环保等优点，但地铁运营过程中地铁区间道床软土地基的长期沉降和差异沉降给地铁的安全运营带来威胁和危害。我国城市地铁正处在大规模建设与运营养护并重阶段，随着地铁建设速度的加快、运营里程的不断加大，减小地铁振动影响和控制累积变形的发展，确保城市轨道交通的运营安全。课题基于原来申报书设定的研究内容，主要开展这几方面的研究工作：①地铁移动荷载作用下软土软化机理的试验模拟研究；②地铁隧道下卧软土地基的长期沉降变化规律研究；③建立稳健的机车—道床—软土地基的耦合模型和长期沉降计算方法；④地铁长期沉降预测技术研究。