【作者】 张琦；

【导师】 辛涛；

【作者基本信息】 北京交通大学 ， 道路与铁道工程， 2017， 硕士

【摘要】 随着我国高速铁路和城市轨道交通的迅速发展,振动噪声问题日益突出。当列车经过时,振动经轨道结构传至下部基础,再由下部基础向周围环境传递,引起周围环境的振动,在敏感地区振动还会影响居民工作和生活。城市轨道交通方面,为解决列车引起的环境振动问题,已经设计了浮置板轨道并起到了一定的减振效果。在高速铁路方面,我国也逐渐尝试浮置板轨道的应用,但是,对浮置板在高速铁路应用后的安全性、减振效果等的研究尚不充分。本文针对高速铁路铺设橡胶浮置板的适用性问题,通过建立高速列车—浮置板轨道—基础动力学分析模型,从轨道结构参数、振动响应分布特征等方面进行了较为系统的研究,可为高速铁路浮置板减振研究提供借鉴。主要有以下几个方面:1、基于有限元方法,建立了浮置板轨道—基础有限元模型,将钢轨简化为梁单元,扣件简化为弹簧阻尼单元,轨道板、自密实混凝土、橡胶减振垫、底座板和基础采用实体单元模拟。基于多体动力学理论,建立了高速列车模型,并通过车轨耦合方法将列车和浮置板轨道—基础有限元模型耦合。2、利用建立的高速列车—浮置板轨道—基础耦合动力分析模型,重点对减振垫铺设型式、减振垫刚度、轨道板厚度、轨道板长度等进行了系统的参数分析。根据谐响应和车轨耦合分析结果,从钢轨、轨道板到底座板和下部基础,振动逐步衰减。相较于轨道板长度、厚度,减振垫铺设型式、减振垫刚度的影响程度更大,二者结果具有良好的一致性。对于路基上浮置板轨道,减振垫面积的减小、刚度的降低,使得系统自振频率会逐渐降低,可显著地降低路基的高频振动。同时,也会造成钢轨变形显著增大,加剧轮轨的力作用,可能带来行车安全方面的不利影响。因此,考虑到行车安全性,减振垫刚度不宜过小。3、利用所建立的高速列车—浮置板轨道—基础耦合动力分析模型,通过不同位置动力响应的统计分析,对轨道和路基振动的垂向分布特征和水平分布特征进行了研究。振动垂向分布特征:浮置板轨道从自密实混凝土到底座板,加速度值急剧减小,普通轨道自密实混凝土和底座板加速度值相差不大。不同位置路基由浅到深,加速度缓慢减小。路基断面分布在轨道位置下方加速度较大,两侧加速度值较小。减振垫以上结构的加速度值离散性较大,减振垫以下结构加速度值较为一致。振动水平分布特征:与普通轨道相比,由于铺设减振垫,轨道板的振动整体增大。浮置板减振轨道轨道板加速度最大值不一定扣件位置,也可能出现在板端位置。路基顶面加速度最大值一般出现在底座板两端位置。减振轨道路基顶面加速度分布界限不如普通轨道明显,路基顶面加速度变化较小。更多还原

【Abstract】 With the rapid development of high-speed railway and urban rail transit in China,the problem of vibration and noise become more and more serious.When the train passes through,the vibration is transmitted to the base from the track structure,and then transferred from the lower part to the surrounding environment.In the aspect of urban rail transit,in order to solve the problem of environmental vibration caused by train,the floating slab track has been designed and the effect of vibration reduction has been achieved.In the aspect of high speed railway,the application of floating slab track has been gradually applied in our country.However,the research on the safety and vibration reduction effect of floating slab in high speed railway is not enough.Aiming at the problem of high speed railway with rubber floating slab,high-speed train-floating slab-foundation model is established.The paper is systematically studied from the aspects of track structure parameters,vibration response distribution characteristics,which can provide a reference for the vibration reduction of high speed railway floating slab track.The main points are as follows:1.Based on the finite element method,a floating slab track-foundation finite element model was established,the rail is simplified as a beam element,the fastener is simplified as a spring damper element,slab track,self-compacting concrete,rubber plate,base plate and foundation are simulated by solid elements.Based on the theory of multi-body dynamics,a high speed train model is established,and the coupling model of train and floating slab track foundation is coupled by the vehicle track coupling method.2.Through the established high-speed train and floating slab track based coupling dynamic analysis model,the effect of systematic parameter was analyzed,including the damping pad laying type,rubber mat stiffness,track slab thickness and track slab length.According to the analysis results of the harmonic response and the vehicle track coupling,the vibration of the rail,the track plate and the bottom plate reduced gradually.Compared with the length and thickness of the track slab,the influence of the type of the rubber mat and the stiffness of the damping pad is greater,and the two results are in good agreement.For the floating slab track on the sub grade,the decrease of the damping pad area and the decrease of the stiffness make the natural frequency of the system decrease gradually,which can significantly reduce the high frequency vibration of the sub grade.At the same time,it will lead to a significant increase in rail deformation and the wheel rail force,which may bring adverse effects on driving safety.Therefore,taking into account the safety of driving,vibration pad stiffness should not be too small.3.Using the high-speed train and floating slab track based coupling dynamic analysis model,by comparative analysis of a large number of reference points of dynamic response of track and subgrade vibration,the paper studied the vertical and horizontal distribution of vibration.The vertical distribution characteristics of vibration are as follows:for the floating slab track,from the self-compacting concrete to the base plate,the acceleration value decreases sharply,and the acceleration value of the common rail self-compacting concrete and the base plate is not big.Different positions of the subgrade from low to deep,acceleration decrease slowly.The distribution of subgrade cross section is larger than that of the track,and the acceleration value is smaller.The acceleration value of the structure above the damping pad is larger,and the acceleration value of the following structure is consistent.The horizontal distribution characteristics of vibration are as follows:ordinary track plate acceleration maximum values appeared in the fastener position,floating slab track plate vibration and the maximum acceleration is not necessarily the maximum fastener position,may also be in the plate end position.The vibration of the track plate increases as a result of laying the damping pad.The maximum acceleration of the top surface of the subgrade usually appears at both ends of the base plate.The limit of acceleration distribution on the top of the subgrade is not as obvious as that of the common rail,and the acceleration of the top surface of the subgrade is smaller.更多还原