基于定点锤击的地铁轨道减振效果评价方法研究

项目名称： 基于定点锤击的地铁轨道减振效果评价方法研究

项目编号： No.51508022

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 建筑科学

项目作者： 马蒙

作者单位： 北京交通大学

项目金额： 20万元

中文摘要： 轨道减振措施作为控制地铁环境振动影响的最有效途径之一，广泛应用于国内各地铁线路。减振轨道在上线铺轨之前，利用定点锤击法在线下准确地评价其减振效果对减振设计、环境振动预测具有十分重要的意义。近年来研究发现：广泛使用的线下定点锤击激励法、与实际线上测试地铁列车通过时的减振效果之间存在较大差异，这直接影响环境振动预测、减振轨道选择及设计。本项目以插入损失为减振效果评价量，旨在分析影响上述差异的因素，给出定量描述这种差异的修正公式，最终实现利用线下定点锤击预测线上移动列车作用下的轨道减振效果。通过实验室试验、现场试验和数值分析，拟解决3个关键问题：（1）定点激励和移动列车激励下轨道减振效果的差异；（2）线下定点激励时，轨道施加不同预载量（含无预载）时减振效果的差异；（3）线下实验室测试与线上实际测试时轨道减振效果差异。本项研究的预期成果可以为今后制定轨道减振产品线下减振效果评价标准提供理论支持。

中文关键词： 环境振动；地铁轨道；减振评价；插入损失；试验研究

英文摘要： Track solution is one of the most effective mitigation methods to control the metro train-induced environmental vibrations, therefore it has been widely used on all metro lines in China. Before the construction of isolated tracks on metro lines, the evaluation of the mitigation effects by fixed-point impulse tests in laboratory is very important for the mitigation design and the environmental vibration prediction. Recent researches show that, the big difference of the mitigation effect exists, however, between the results from the off-line laboratory test by fixed-point impulse loads and the on-line in-situ measurement by moving trains. The difference misleads the environmental vibration prediction and the selection and design for isolated tracks. In this project, Insertion Loss is used as the evaluation descriptor. The factors which cause the different mentioned above will be analyzed. Then, a modification formula will be suggested to describe the difference. Finally, the vibration mitigation effect under moving train loads will be predicted by the impulse test in laboratory. By laboratory tests, the in-situ measurements and numerical studies, three key problems are planed to solve: (1) analyzing the difference of the mitigation effect between fixed-point impulse loads and moving train loads; (2) analyzing influence to the mitigation effect by different pre-load weights, including no pre-load; (3) analyzing the difference of the mitigation effect between the off-line test in laboratory and the on-line in-situ measurement. The expected results will provide the theoretical support for the guidelines of the track mitigation effect evaluation in laboratory in future.

英文关键词： environmental vibration;metro track;vibration reduction evaluation;insertion loss;experimental study