【作者】 胡华锋；

【导师】 高亮；

【作者基本信息】 北京交通大学 ， 道路与铁道工程， 2014， 博士

【摘要】 摘要：我国高速铁路以无砟轨道为主,与有砟轨道相比,其具有稳定性、刚度均匀性和耐久性好,平顺性高、维修工作量少等突出优点。板式轨道是无砟轨道的主要形式,由钢轨、扣件、轨道板、板下充填层以及混凝土底座等组成。充填层的服役性能对高速行车的安全性、舒适性以及无砟轨道结构自身的稳定性和耐久性均具有重要影响。因此,在板式无砟轨道设计中,对充填层静动态力学性能研究及关键设计参数的确定尤为重要。然而,目前尚缺少对高速铁路板式无砟轨道充填层的完整理论体系、评价检算方法与试验验证,板式无砟轨道的充填层结构设计、材料选型缺乏依据。论文针对高速铁路CRTSI型板式无砟轨道,在归纳总结国内外水泥乳化沥青砂浆充填层相关研究成果的基础上,建立起能详细考虑充填层特性的单元板式无砟轨道空间静、动态理论分析模型,依据充填层的功能定位系统开展充填层力学性能与关键参数的分析,提出CRTSI型板式轨道充填层的功能定位以及设计参数的指导性建议。结合充填层材料服役性能室内试验研究,进行充填层力学性能、耐久性能和施工性能的演变规律研究及参数优化分析,研究成果可为充填层的设计提供理论支撑并指导其现场施工,另外通过动力学理论仿真和哈大线现场实车试验对研究成果进行验证和评估。本文主要工作及成果如下：1)建立能充分考虑充填层特性的单元板式无砟轨道空间耦合静力分析方法。针对高速铁路CRTSI型板式无砟轨道结构,基于弹性地基梁体理论,应用有限单元法,建立了能充分体现充填层支承调整、缓冲协调、弹性阻隔等各方面特性的单元板式无砟轨道空间耦合静力分析精细化模型。模型中采用了广义Maxwell模型以充分考虑充填层材料的粘弹性本构关系。2)建立能充分考虑充填层参振特性的列车-无砟轨道-下部基础空间耦合动力学理论。将车辆视为一个由悬挂弹簧和阻尼联系起来的7刚体共31个自由度的振动系统,轮轨作用由赫兹非线性弹性接触理论和蠕滑理论确定。将钢轨视为弹性点支承基础上的Beraoulli-Euler梁,轨道板视为弹性基础上的弹性实体,凸形挡台及CA砂浆充填层对轨道板提供横垂向非线性弹性约束,底座板视为弹性地基上的弹性实体。并通过不同车速下轨道结构动力学特性的仿真结果与哈大线实测数据的对比验证了模型的正确性和准确性。3)提出了CRTSⅠ型板式无砟轨道充填层功能定位、力学性能与关键设计参数。为系统开展充填层力学性能及其影响因素分析,需首先将其作为系统结构层之一进行功能定位,根据其在结构体系中的支承、传载、减振、隔振、阻裂五大功能特点进行参数辨识并构建针对性强的计算模型,通过大量数值模拟分析探索充填层厚度、密度、弹性模量及其粘弹性本构关系等参数对各项功能的影响,总结提出了充填层功能及参数的指导性建议。4)揭示了CA砂浆充填层厚度、弹性模量等参数及轨道板空吊、砂浆充填不满、充填层刚度不均匀等病害对轨道动力特性的影响规律。利用建立的列车-无砟轨道-下部基础空间耦合精细化动力学模型,对CRTS Ⅰ型板式无砟轨道的动力学特性进行研究；结合静力分析部分的研究成果,研究CA砂浆充填层厚度、弹性模量等参数以及轨道板空吊、砂浆充填不满、充填层刚度不均匀等病害对轨道动力特性的影响规律,为我国无砟轨道的检测、监测、养护维修工作提供理论依据。5)基于结构和材料的试验研究提出了CRTS Ⅰ型板式无砟轨道充填层材料服役性能。建立了CRTS Ⅰ型板式无砟轨道试验模型,测试了不同充填层材料及工况的轨道系统振动与噪声特性,得到了基于减振、降噪与变形协调等功能的充填层材料及施工工艺类型；进行了充填层材料的耐水、抗冻、温度疲劳等耐久性试验,并结合充填层的施工特点,提出了用于CRTS Ⅰ型板式无砟轨道充填层的CA砂浆性能指标。6)开展了CRTS Ⅰ型板式无砟轨道充填层动力学性能试验研究。通过无砟轨道充填层材料实车试验,分析行车条件下不同无砟轨道充填层砂浆配方对轨道结构动力性能的影响；另外,针对桥梁、路基、隧道等典型线下基础进行不同车速下CRTS Ⅰ型板式无砟轨道结构动力特性的高速实车试验研究；通过依据轮轨系统动力学评价指标,如脱轨系数、轮重减载率、轮轨作用力、轨道结构的动力学强度等评估CRTS Ⅰ型板式无砟轨道结构体系的动力性能、行车安全性、舒适性,测试结果验证了理论研究的正确,并为板式无砟轨道结构充填层的设计、优化提供了试验依据。更多还原

【Abstract】 Compared with ballasted track, non-ballast track has such advantages as stability, stiffness uniformity, good durability, high regularity and less maintenance, etc. It is developed rapidly and widely used because it suits to the high speed and traffic density of high-speed railway in China. Slab track is an advanced structure form of non-ballast track. It is composed of rail, fastener, track slab, filling layer of cement emulsified asphalt mortar (CA mortar) and concrete base, etc. The service performance of the filling layer has great influences on a train’s safety and comfort as well as the stability and durability of slab track structure itself. Therefore, in the design of slab track, it is particularly important to grasp mechanical properties and design parameters of filling layer. There is still a lack of complete theoretical system, evaluation methods and experimental verification of high-speed railway slab track filling. The structure design and material selection of filling layer is still in the study.Focusing on CRTS I slab track, a static and dynamic analysis theory of unit slab track with full consideration of filling layer characteristics were established on basis of related research achievements of CA mortar filling layer both at home and abroad. The mechanical properties and parameters of the filling layer were analyzed according to its functional orientation. Then this thesis put forward some guidance for the functions and parameters of CRTS I slab track filling layer. It also studied the design parameter optimization and performance evolution of the filling layer material based on a series of laboratory experiments. The research results were testified and evaluated by dynamics simulation and field dynamic tests in Harbin-Dalian passenger dedicated line. This has provided theoretic support and practical guidance for popularization and application of the filling layer. The main research and results obtained are as follows:1. Space coupling statics analysis method of the unit slab track with full consideration of filling layer characteristics were established.Based on elastic foundation beam/solid theory, a space static calculation model of unit slab track was established by application of finite element method (FEM). And this model fully reflected various performance of the filling layer, such as support, adjustment, buffer, coordination and flexible barrier, etc. The viscoelastic constitutive relation of the filling layer materials was taken into consideration by adopting generalized Maxwell model.2. High speed Vehicle-ballastless track-substructure coupling dynamic theory with full consideration of filling layer vibration characteristics were established.Rolling stock is deemed to be a vibration system of7rigid body and31DOFs linked by a suspension spring and damping. The wheel/rail normal force is determined by Hertz nonlinear elastic contact theory, while creep theory determines the tangential creep force. Rail is viewed as a Bernoulli-Euler beam based on the elastic point support, considering vertical, horizontal and rotational DOFs of the left and right rails respectively. The supporting point space is fastener spacing intervals. Track slab is deemed as vertically an elastic entity on an elastic foundation, laterally as a rigid body motion, considering translational and rotational DOFs, convex block and of CA mortar filling layer provide lateral and vertical nonlinear elastic constraint for track slab. The concrete base is a flexible entity on elastic foundation. And model is proved to be correct and accurate through comparison of simulation results and experimental results.3. The functional orientation, mechanical properties and parameters of the CRTS Ⅰ slab track filling layer were systematically analyzed.In order to analyze the mechanical properties of filling layer and its influencing factors systematically, it should be viewed as one of the structural layer in non-ballast track system and carried out the functional orientation analysis. The targeted calculation model was established according to its five functions, i.e. support, load transmission, vibration reduction, vibration isolation, crack resistance. The influence of various filling layer parameters such as thickness, elastic modulus and viscoelastic constitutive relation on its performance was analyzed through a lot of static and dynamic calculation results. Thus, it summatively proposed the functions and parameters guiding recommendations of CRTS Ⅰ slab track filling layer.4. The influence of CA mortar filling layer parameters and damages on the dynamic characteristics of the CRTS Ⅰ slab track were revealed.High speed Vehicle-ballastless track-substructure coupling dynamic model was used to analyze the dynamic characteristics of the CRTS Ⅰ slab track. Combined with static analysis results, the influence of CA mortar filling layer parameters, such as thickness, elastic modulus, and damages, such as slab hanging, mortar filling lack and stiffness uneven, on the dynamic characteristics of the CRTS Ⅰ slab track were researched. Research results provide some theoretical support for the detection, monitoring, maintenance and repair works of ballastless track.5.The filling layer material service performance laboratory experiments were carried out systematically. A scale model for CRTS Ⅰ slab track was produced to test the track system vibration and noise characteristics under different conditions with various filling layer materials. Then, the filling layer material and construction technology type with good performance of vibration and noise reduction, deformation coordination were obtained. The durability of filling layer materials was tested. Combined with its construction characteristics, performance indicators for the CA mortar filling layer of CRTS Ⅰ slab track were put forward.6. Field dynamic performance test research of CRTS Ⅰ slab track combined to conduct the dynamics evaluation was carried out.The vehicle and non-ballast track were viewed as an interaction system. The influence of various mortar formulas on dynamic performance of slab track structure was analyzed through field dynamic tests. In addition, under different high-speed condition, impact of the different substructures such as bridge, roadbed and tunnels was tested. According to indicators system of wheel/rail system dynamics evaluation, such as derailment coefficient, wheel load reduction rate, vertical and lateral wheel/rail force, the dynamic strength of the track structural components, etc. the dynamic performance of the track structure and train’s running comfort were evaluated so as to provide some theoretical support and experimental basis for the design and optimization of filling layer in non-ballast structural system, and test results verify the theoretical study.更多还原