【作者】 陈建国；

【导师】 夏禾；

【作者基本信息】 北京交通大学 ， 桥梁与隧道工程， 2010， 博士

【摘要】 随着经济和社会的不断发展,城市规模的不断扩大,城市人口也逐步增多,轨道交通因其优点得到了快速发展,我国轨道交通系统的建设如今已经达到一个高潮期。但轨道交通系统在方便人们出行的同时给周围环境造成的振动影响也与日俱增,已经引起了人们的普遍关注。高架结构作为一种主要的承载结构在轨道交通系统中得到了广泛应用,因此研究高架轨道交通引起的环境振动具有重要意义。本文对高架轨道交通引起的环境振动预测和影响参数进行了研究。通过建立车辆-桥梁-地面模型对各影响参数进行了对比计算,提出了适合工程使用的环境振动预测公式,并通过现场试验对高架轨道交通列车引起的环境振动进行了验证。主要研究内容包括：(1)研究了弹性支座简支梁在移动荷载作用下的动力响应。通过对弹性支座梁的振型推导,得到了弹性支座梁的振型函数。并分别对移动竖向荷载作用下弹性支座梁、移动竖向和纵向荷载共同作用下弹性支座梁、移动弹簧阻尼体系作用下弹性支座梁及匀变速移动荷载作用下弹性支座梁的动力响应进行了理论推导。并对理论进行了数值计算,得到了一些有意义的结论。(2)对北京地铁5号线高架桥线路周围地面进行了环境振动测试,将测试得到的地面振动加速度数据在时域和频域内进行了分析,得到了以下结论：普通轨枕下的地面振动在近振源点处大于梯形减振轨道下的地面振动,远振源点处小于普通轨枕下的地面振动；地面横向振动随距离的衰减表现为先增大后减小；竖向振动的衰减规律总的趋势是逐渐减小,但有一个明显的反弹区,且振动越大反弹越明显；梯形轨枕能够对一定频率范围内的振动起到减振效果,但是对某一频率范围的振动会有所放大；高频振动的衰减速度大于低频振动的衰减速度；远振源点的振动主要是由低频的振动引起的。(3)建立了高架轨道交通引起环境振动的计算模型。本模型包括列车-桥梁子结构模型和墩-土子结构模型,通过建立列车-桥梁的振源模型,可以求出桥墩顶部的激励力,将墩顶部的激励力作用在用有限元软件建立的三维墩-土模型,即可以求出自由场地任意一点的振动响应。运用计算模型对各种影响因素进行了计算,影响因素包括：轨道不平顺、列车速度、地基土性质、桥梁跨度以及与振源的距离等。(4)根据计算结果运用回归方法得到了适合工程应用的高架轨道引起环境振动的预测公式。并通过现场试验结果对预测公式的适用性和准确性进行了对比验证。结果表明：本预测公式具有较强的适用性和准确性。更多还原

【Abstract】 With the development of economy and society, the urbanization expands and the population increases continuously. The rail traffic, due to its advantages, has been developed at a fast speed and the construction of rail traffic system reaches a peak period. However, the vibration influence on nearby environment induced by rail traffic is becoming more and more serious, which has been paid more and more attention. Viaduct is one of the main load-bearing systems of rail traffic and has many successful applications. Therefore, it is very important to study environmental vibration induced by trains running on the viaduct.The prediction of environmental vibration and its influence factors have been studied in this dissertation on the basis of train-bridge-ground numerical model and the analysis of some influencing factors. The prediction formula of environmental vibration induced by viaduct trains have been obtained and furthermore validated by the experimental results. The main contents include:(1) The dynamic response of simply-supported beam with elastic support is studied. The functions of mode shapes for those beams with elastic support are achieved by theoretical deducing. Furthermore, the dynamic responses of simply-supported beam with elastic support under different loads are studied. The loads include vertical moving load, vertical and horizontal moving load together, moving spring-damping system and moving load with evenly variable velocity. The numerical calculation is carried out by means of the theoretical formulation and some valuable conclusions are drawn up.(2) The in-situ experiment of environmental vibration is carried out on the viaduct part of Beijing Metro Line 5. The measured data are analyzed in time domain and frequency domain, respectively. The following conclusions are obtained:the ground vibration near pier for normal track is larger than that for ladder track; the ground vibration far from the pier for normal track is smaller than that for ladder track; the propagation characteristic of horizontal ground vibration shows increasing tendency firstly and then decreasing tendency; the propagation of vertical ground vibration shows the tendency of decreasing continuously; there appears an obvious renounced region and the phenomena is more obvious with the increasing of vibration level; the ladder track has the effect of decreasing some vibrations at certain frequency range and however increase some vibration at another different frequency range; the attenuation of those vibrations with high frequency is faster than that with low frequency; the vibration of far field is mainly caused by those vibrations with low frequency.(3) The numerical model of vibration induced by viaduct trains is established. The model includes train-bridge sub-model and pier-soil sub-model. By establishing vibration source model of train-bridge, the load acting on the top of pier can be calculated. Then the force on the top of pier can be applied to a 3D pier-soil model established by FEM software. Finally, the vibration response of any point on free field can be calculated. In the FEM model are taken into account several influence factors including rail irregulation, train speed, soil parameters, bridge span and distance to pier.(4) The prediction model of environmental vibration induced by viaduct trains is obtained based on calculated results by means of regression method. The prediction model is validated by the experimental data, and the conclusion show that the model has high adaptation and accuracy.更多还原