【作者】 罗强；

【导师】 蔡英；

【作者基本信息】 西南交通大学 ， 道路与铁道工程， 2003， 博士

【摘要】 随着行车速度的提高，对轨道的平顺性要求愈加严格。由于路堤与桥梁的工程性质迥异，在路桥交界处极易产生严重的轨道不平顺问题。本文根据路桥过渡段的变形特性，以及车辆／线路相互作用的特点，在综合参考了国内外有关技术资料的基础上，对高速铁路路桥过渡段的动力学特性进行了理论分析和工程试验研究，主要工作及结论如下： 1．高速铁路路桥过渡段动力学特性计算分析及评价 在国内最早应用车辆与线路相互作用的动力学理论，全面分析了路桥过渡段轨面弯折变形、轨道基础刚度变化、行车速度、车辆驶向等因素对高速铁路路桥过渡段动力学特性的影响规律。计算结果表明，由路桥结构的工后沉降差引起的轨面弯折变形是影响高速列车安全与舒适运行的主要因素，应重点处理；由路桥间刚度差引起的轨道基础刚度的变化对高速行车的影响不显著，不成为控制条件：车辆进出路桥过渡段的动力学特性指标变化不大，列车的驶向不起制约作用；以本文建立的动力学特性评价指标(初步)的控制值为目标函数，可得不同速度等级的路桥过渡段不平顺控制标准(轨面弯折角)为：V=160km／h、θ≤5.5‰，V=250km／h、θ≤3‰，V=350km／h、θ≤1.5‰，该限值与日本等相关的研究成果吻合甚好。 2．高速铁路路桥过渡段结构设计与技术标准 根据国内外路桥过渡段工程处理措施的有关资料，路桥过渡段动力学特性分析结果，以及已有的工程实践经验和研究成果，提出了针对不同速度等级的路桥过渡段结构设计与技术标准，其中的部分内容已纳入了“时速200公里新建铁路线桥隧站设计暂行规定”和“京沪高速铁路线桥隧站设计暂行规定”之中，在秦沈客运专线的建设中得到了应用，其工程效果正在接受营运检验。 3．土工格栅加筋砾石土变形特性试验研究 在一个长1.0m×宽1.0m×高2.0m的刚性模型箱内，进行了七组改变土工格栅铺设间距和砾石土压实密度的三向加载大比例模型试验，测试了土工格栅加筋砾石土试样，在不同侧向压力(柔性水囊侧向加载技术为国内首次应用)作用下的竖向荷载与变形关系曲线。试验结果表明，铺设土工格栅能显著减小砾石土试样在竖向荷载作用下的变形，其效果与土工格栅铺设间距第H页西南交通大学博士研究生学位论文成反比;提高砾石土的压实密度，能更加显著减小砾石土试样在竖向荷载作用下的变形;在不易碾压密实的过渡段狭窄区域内铺设土工格栅，可利用土工格栅加筋结构的抗变形能力，较显著地降低路堤的压密下沉，达到减小路桥间沉降差的目的。 4.高速铁路路桥过渡段不均匀沉降特性测试 为了研究高速铁路路桥过渡段的不均匀沉降特性，检验提出的高速铁路路桥过渡段结构设计和技术条件(标准)的适用性，率先在新建铁路济邯线和秦沈客运专线的4座桥台位置进行了过渡段设计、施工、检测技术，以及沉降特性的实体测试。测试结果表明，设置过渡段对均化路桥间的不均匀沉降有良好效果，能达到使路桥间的工后沉降差逐渐过渡的目的;良好地基条件下(尸、21·ZMpa，E之15一ZOM尸a，K3。七60一7oMoa/m)，过渡段路堤地基的总沉降约为路堤高度的0.5%一1 .5%，其中的80%发生在施工期间，工后沉降只占20%;采用优质填料(以级配粒料为主)，进行充分压实的过渡段路堤，其自身的工后沉降十分微小，路基面的沉降主要由地基下沉引起;在地基条件、填料性质和压实参数等满足设计暂行规定技术标准的情况下，过渡段路基面的沉降在竣工后的初期发展较快，0.5~l年后就能基本稳定。 5.高速铁路路桥过渡段动力学特性测试 为了研究高速铁路路桥过渡段的动力学特性，检验高速铁路路桥过渡段工程处理措施的有效性，首次在新建铁路秦沈客运专线的3座桥台位置，进行了2种车型共127次高速行车条件下的过渡段动力学测试(最高速度达30 1 km/h)。测试结果表明，车辆轴重对路基动力学响应的影响十分显著，列车编组中轴重最大的车辆对路基的动力作用最强烈，成为路基(动力)设计的控制条件;路基动应力的速度影响系数最大值为0.00269(km/h)’，平均值的99%上置信限为0.001 18(km/h)一l，均小于0.003(km/h)一’的设计控制值;桥台背设有钢筋混凝土过渡搭板和片石混凝土墩的加筋路堤过渡段结构型式的过渡效果最好，其次为设有片石混凝土墩的加筋路堤过渡段结构型式，未设钢筋混凝土过渡搭板和片石混凝土墩的加筋路堤过渡段结构型式，在动应力、动位移、加速度、动反应模量等方面均未达到理想的过渡形态;.车辆的驶向对过渡段路基的动力学响应无实质性影响。关键词高速铁路;路基与桥梁过渡段;车辆与线路相互作用;动力学特性;不均匀沉降;土工格栅加筋砾石土更多还原

【Abstract】 With the increase of the train running speed,the requirements on the smoothness of the rails have become more and more strict.Since the engineering properties of embankments and bridges are quite different,serious unevenness is prone to occur in the linking of embankments and bridges.On the basis of consulting the relative domestic and overseas technical materials,this paper conducts theoretical analysis and engineering test studies to the dynamic performance of the bridge/approach embankment on high-speed railway as per the deformation occurrences of the bridge/approach embankment and the features of vehicle-track interaction.1. Calculation,Analysis and Assessment of the Dynamic Performance of the Bridge/Approach Embankment on High-Speed RailwayThis paper has comprehensively analyzed the effect patterns of the factors such as the bending deformation of the rail top,the rigidity change of the rail foundation,the train running speeds,the train running direction and other factors on the dynamic performance of the bridge/approach embankment of high-speed railway for the first time in China.The calculation results have demonstrated that the rail top bending deformation resulted by the settlement difference of the embankment and bridge is the main factor that effects the safe and comfortable running of high speed trains,the handling of which should be emphasized;the rigidity changes of the track foundations resulting from the rigidity differences between the embankment and bridge should not become the control conditions.The changes in the indexes of dynamics performance are not big when trains pass through the bridge/approach embankment of high-speed railway and the running direction of trains will not play a restricting role.Taking the control values of dynamics performance assessment indexes preliminarily established by this paper as the target function,the unevenness control standards(rail top bending angle)of the bridge/approach embankment under different speed grades are:V=160km/h, θ≤5.5‰ , V=250km/h, θ≤3‰ ,V=350km/h.1.5 ,which are very good because they tally with the relative Japanese research results.2. Structure Designs and Technical Standards of the Bridge/Approach Embankment on High-Speed RailwayThis paper has put forth the structure designs and technical standards for the bridge/approach embankment under different speeds in light of the analysis results of the dynamic performances of the bridge/approach embankment by the relative domestic and overseas materials about the treatment measures for the bridge/approach embankment and the practical experience and research results of the existing projects;part of the contents of which have been put into the"Temporary Requirements for Design of Railways, Bridges, Tunnels and Stations of Newly Built Express Railways -with 200km/h Trains"and the" Temporary Requirements for Design of Railways, Bridges,Tunnels and Stations of the Beijing-Shanghai High-Speed Railway",which has been applied in the construction of the Qinhuangdao-Shenyang dedicated passenger line and the engineering effects of which are being tested by its operation.3. Tests and Study on the Deformation Properties of Geogrid-Reinforced GravelThe seven groups of large scale model tests to change the laying separation interval of geogrid and the compact density of gravel have been conducted in a rigid model box with the sizes of length l.Omxwidth l.Omxheight 1.0m that measured and tested the longitudinal loads and deformation curves of the geogrid-reinforced gravel samples under the actions of different lateral pressures(It was the first time for the lateral load-on technology by flexible pocket of water to be used in China).The test results have demonstrated that the laying of geogrid can significantly reduce the deformation of the gravel samples under the actions of the longitudinal loads.the effects of which are inversely proportional to the laying separation interval of geogrid;the deformation of the gravel samples under the actions of longitudinal loads can be significantly decre更多还原