【作者】 彭波；

【导师】 蒋沧如； 王克显；

【作者基本信息】 武汉理工大学 ， 结构工程， 2003， 博士

【摘要】 随着国民经济的飞速发展，铁路、地铁和城市轨道交通系统也在全国进入建设高潮，与此同时列车运行产生的振动对环境的影响也越来越大，已到了必须重视的地步。但是，目前国内对沿线环境振动的评价、预测方法仍以现场实测和经验公式为主，误差较大，缺乏系统的研究和定量的分析方法，因此不能在建设前有效地指导设计与施工。为了正确评价轨道沿线环境的振动，有必要深入研究列车荷载作用下地基土的动力响应。 本文以列车荷载作用下的轨道、高架桥和地基为研究对象，分析了轨道交通荷载作用下地基土的响应，得到振动在地基土中的传播特性。对振动较大的轨道沿线采用了两种不同的减振措施，并对减振效果进行分析比较。 本文主要研究了以下几个方面的问题： 1、综述了已有的轨道模型以及各种模型适用的研究范围。在此基础上选取Euler梁模型以及Timoshenko梁模型进行分析。从计算结果看，在研究高速移动荷载作用下轨道系统的动力响应这种特定情况下，本文提出的模型与计算方法是合理的。 2、考虑到地基振动对建筑物产生的直接影响，本文对移动荷载引起的地基响应作了详细的研究。由于地质条件的复杂性，将地基看成是层状的，并且每层都是均匀弹性的，通过解三维弹性体的波动方程(Navier方程)得到地基在移动荷载作用下的波数-频域的解，再通过快速Fourier逆变换(FFT)求得空间-时间域的解。基于分层法的解析算法，得到了在不同点以及在同一点但不同地质条件下的时程分析曲线、加速度变化曲线和传递函数反应谱，结果表明，地基土在x、y、z三个方向的响应都是随时间变化的，并且伴随有明显的波动现象产生；对于相同地质条件的不同观察点，距离荷载作用线越远的地方振幅越小，即振动具有明显的衰减性。 3、关于轻轨列车荷载作用下的地基土的振动分析，本文考虑到轻轨的结构形式一般为高架桥，与普通铁路和地铁不同，因此，本文对这一问题进行了专门研究。高架桥系统对周围环境的影响是通过高架桥的柱子而产生的，其特征是荷载位置不变，但大小随时间变化。对这一问题的计算，只需能够求得列车武汉理工大学博士学位论文荷载作用下桥墩的时程曲线，则现有的有限元软件ANSYS己能较好地求解。因此在计算轻轨列车荷载作用下地基土的响应时，本文运用ANSYS软件进行模拟，在振动较大的地方采用设置阻波区(WIB，wave Impeding Block)和隔振沟两种减振措施，同时对减振效果进行分析比较，得到了较为理想的结果。通过本文的研究成果表明，轻轨的振动分析可以服务于轻轨工程的可行性研究、设计与施工，为政府决策部门提供依据，对轨道系统运行时产生的环境振动较敏感的建筑物采取合理的隔振与减振措施进行指导，并对减振效果进行预评价。 最后，在全面总结论文工作的基础上，提出本课题尚待深入研究的若干问题。更多还原

【Abstract】 With the rapid development of the national economy, the construction of railway, subway and urban rail-viaduct system have been reached a new climax in present period. At the same time, the influence of the vibration caused by the moving vehicles on the near environment has been increased and paid close attention to. Up to now, the methods used for the evaluation and forecasting of the environmental vibration along the whole railway have still been the field survey and some empirical formulas which will result in certain errors, the systematic study and the quantificational analysis on this problem have not been performed in our country. So it is impossible to instruct the design and construction of rail transportation effectively. In order to evaluate the vibration along railway correctly, it is necessary to lucubrate the dynamic response of ground bearing the moving loads of vehicle.In this paper, regarding the rail, viaduct and ground as study objects, the response of ground under the moving loads on rails are analyzed in detail and the propagation characteristic of vibration in the ground are concluded. In addition, two kinds of vibration-decreasing measures are applied on the rail lines with big vibration, and the effects of decreasing vibration are also analyzed comparatively.The main study includes the following aspects.1. Introducing some rail models in existence and their respective research direction in point. Considering our purpose is studying the dynamic response of ground under the speedy moving loads, the Euler beam model and Tirnoshenko beam model are selected here to be rail models. In this particular condition that studying the dynamic response of rail system under the speedy moving loads, it has been already proved by the calculation results that the rail models and calculating methods applied in this problem are rational.2. Taking account of the direct effect of ground vibration on buildings, the ground responses caused by the moving loads is studied in detail. Because of the complication of ground condition, the ground is regarded as continuous layers and each layer of soil is defined as a uniform and elastic object. By solving the wave equation (Navier Equation) of three-dimensional elastic object, the results of groundunder moving loads in wave number ?frequency field are obtained, then through the rapid Fourier reverse transform, the results in space-time field are obtained. Based on the resolving algorithm of continuous-layer method, the time order analyzing curves, acceleration curves and the response spectra of transfer function at the different points of the ground and at the same point on the different ground conditions are gained. It demonstrates that the responses of ground in x, y and z axial directions all change by time, and the obvious wave propagation appears in ground. For different observing points on the same ground condition, at more distant points from the load line, the less swings are found, that is to say, vibration possesses the obvious characteristic of attenuation.3. The ground vibration caused by load of vehicle in light railway system is analyzed as well. Different from the common railway and subway, the viaduct is the main structural member in light railway system, which is studied in specialty in this paper. The effect of viaduct system on near environment is generated through the column of viaduct, so the characteristics of loads are that the action points do not change but the values change with time. For the modeling of this kind of problem, because the time-order curves of viaduct column bearing the loads of vehicles are expect to get, the present finite element analysis software ?ANSYS can be used to solve it quite well. So ANSYS is applied here to calculate the response of ground under moving loads in light railway system. At the locations with the big vibration, two measures for vibration-diminishing ?Wave Impeding Block and Open Drain for Isolating Vibration are constructed, and the effective of vibration-diminishing is analyzed更多还原