轨道交通引起的振动在成层土中的传播规律

发布时间：2018-09-19 11:10

【摘要】：随着轨道交通事业的快速发展,特别是轨道线路越来越多地覆盖城市地区,地面轨道交通产生的噪声与振动对周围环境产生了重要影响。一方面,噪声与振动达到一定等级将会干扰人们的日常生活,甚至影响人们的情绪、睡眠、休息和学习；另一方面,振动还会导致地基产生液化、基础下沉或不均匀下沉,墙体裂缝,建筑物倾斜甚至局部损坏,特别会对精密仪器的厂房、医院、实验室等对振动特别敏感的建筑产生不可估量的损失,因此对轨道交通引起环境的振动问题也越来越被广泛关注。本文在总结了国内外研究现状,系统阐述了轨道交通引起环境振动的研究成果及目前的研究形势。通过大型有限元软件ANSYS建立列车-轨道—路基三维空间有限元模型,进行瞬态分析,从不同的角度考虑轨道交通运行时带来的冲击荷载作用下铁路轨道和地基的动力相互作用,给出了列车运行时引起地面振动的衰减规律和振级评价。其分析结果可以为城市轨道交通工程减隔振设计和使用提供理论依据。主要研究内容及成果如下：(1)通过ANSYS有限元软件建立列车—轨道—路基的三维模型对上海地铁二号线机场延长段进行模拟。采用人工粘弹性边界,荷载采用激振力荷载,模型选用全模型的一半进行计算,节省计算时间,提高计算效率,比较精确的模拟了上海地铁二号线机场延长段的实际振动情况。(2)为了明确轨道结构和地基特性对列车交通荷载作用下产生的地基振动和波动传播特性的影响,通过不同角度考察了不同振动方向、不同测点、不同车速情况下,竖向振动加速度变化规律及振级评价,此外总结了振动频率的变化规律。(3)比较了空沟(隔振沟)、隔振连续墙、排桩这三种不同隔振措施的隔振效果,用对比的方法表现了在未隔振和设置了不同隔振措施情况下三维地基表面的动力响应。对三种隔振措施的适用范围做了简要的说明。对隔振措施的深度、宽度、厚度以及排桩的排数均进行了分析评价。
[Abstract]:With the rapid development of rail transit, especially rail lines covering urban areas more and more, the noise and vibration produced by ground rail transit have an important impact on the surrounding environment. On the one hand, noise and vibration to a certain level will interfere with people's daily life, and even affect people's emotions, sleep, rest and learning; on the other hand, vibration will also lead to liquefaction of the foundation, foundation sinking or uneven sinking. Cracks in the wall, inclining or even partial damage to buildings, especially to buildings with precision instruments, hospitals, laboratories, etc., which are particularly sensitive to vibration, will cause incalculable losses. Therefore, environmental vibration caused by rail transit has been paid more and more attention. In this paper, the current situation of research at home and abroad is summarized, and the research results and current situation of environmental vibration caused by rail transit are systematically expounded. The three-dimensional finite element model of train, track and subgrade is established by ANSYS, and the transient analysis is carried out. The dynamic interaction between railway track and foundation is considered from different angles under the impact load brought by rail transit. The attenuation law and vibration level evaluation of ground vibration caused by train operation are given. The results can provide a theoretical basis for the design and application of vibration isolation in urban rail transit engineering. The main research contents and results are as follows: (1) the 3D model of train-track subgrade is established by ANSYS finite element software to simulate the extension section of Shanghai Metro Line 2 Airport. The artificial viscoelastic boundary is adopted, the load is loaded by exciting force, and the model is calculated by half of the whole model. The calculation time is saved and the calculation efficiency is improved. The actual vibration of the Yanchang section of Shanghai Metro Line 2 Airport is simulated accurately. (2) in order to clarify the influence of track structure and foundation characteristics on the vibration and wave propagation characteristics of the ground caused by train traffic load, The variation law of vertical vibration acceleration and the evaluation of vibration level under different vibration directions, different measuring points and different speeds are investigated through different angles. In addition, the variation law of vibration frequency is summarized. (3) the gap (isolation ditch) and vibration isolation continuous wall are compared. The vibration isolation effect of three kinds of vibration isolation measures is compared, and the dynamic response of 3D foundation surface without or with different vibration isolation measures is demonstrated by contrast method. The application scope of three kinds of vibration isolation measures is briefly explained. The depth, width, thickness and the number of piles are analyzed and evaluated.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U211.3;TU43

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