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轨道结构垂向荷载传递与路基附加动应力特性的研究

STUDY ON THE VERTICAL LOAD TRANSMISION THROUGH THE TRACK STRUCTURE AND THE CHARACTERISTICS OF SUBGRADE DYNAMIC STRSSES

【作者】 李子春

【导师】 杨灿文; 周镜; 叶阳升;

【作者基本信息】 铁道部科学研究院 , 岩土工程, 2000, 博士

【摘要】 高速铁路轨道结构各部件质量的提高、机车车辆的改进以及严格的轨道管理维护标准使得轨道结构的荷载传递有别于低速铁路。本文以大量实测数据为基础结合理论分析对垂向荷载的传递及分配进行研究。高速列车运行对轨道结构产生的动力效应是不容忽视的,以大系统耦合动力学理论为基础对影响路基附加动应力的因素进行分析亦是本文研究的主要内容之一。 影响垂向荷载的因素是多方面的,但以速度为各影响因素的综合代表参量总结其变化规律是可行的。通过对试验数据的统计分析,得出综合动载系数的计算方法。 通过对轨道结构系统动力响应的分析,认为其在机车车辆荷载作用下处于弹性工作状态,以此为基础,建立轨枕荷载分配模型及道床中应力扩散模型。模型应用于道床及路基附加动应力的计算,其结果与实测数据符合较好。为了方便计算,本文给出轨下及轨枕中心位置路基附加动应力在单位荷载作用下沿深度方向的计算系数。 针对高速铁路轨道结构系统各组成部件设计荷载取值的不协调性,本文提出完整的荷载统一协调模式,并提出设计荷载安全系数的概念,使隐含在各荷载取值计算中的安全储备显式化。 路基的变形控制是保证轨道平顺性的关键因素之一。本文以软土地区路基为对象,对路基的永久及回弹变形作分析计算,并对应力和变形的影响控制范围进行了分析讨论。 以编制的平面车辆一轨道结构耦合动力学分析计算程序为基础,从机车运行速度、路基刚度、路基阻尼及轨道的平顺性(不平顺类型、波长、波深)四个方面对路基附加动应力的变化规律作模拟计算分析,并对结果进行综合讨论。

【Abstract】 Improvement of the track Structure components' and' vehicle' qualitycompanyting with the strict track irreguarity management and maintennance standardresulted in the difference of the load transformation and distribution through trackstructure between the high-speed railway and regular one. Based on a lot of sitemeasurement together with theoretical analysis, how the vertical forces transformthrough the track structure and its principals are studied. The dynamic resposes ofthe track structure caused by high-speed cars and locomotives can’t be neglected, sothe additional dynamic stresses of subgrade are analyzed according to the coupingdynamic mechanics.Many bfactors are the reasons for the change of vertical load, taking the velocityof vehicles as their representative parameters is suitable from the experience. Methodfor calculating the synthesized dynamic additional coeffcient is determined by thestatistic analysis of the site experimental data.According to the dynamic response analysis of track structure, the conclusion ismade that the track structure is in the elastic work status under dynamic load causedby cars and locomotives. Taking the conclusion as bases, a transformation anddistribution model for the vertical forces through the ties and ballast is established.Comparison between the calculating results based on the model and the sitemeasurement shows tbat the model established can reflect the actual work status of track structure system. In order to simplify the calculation, coefficients are given for calculating additional dynamic stresses along the direction of depth by unid loadcaused by vehicles at the locations under rail and center of subgrade.The design load for the components of the track structure is not coordinatedwith each other according to the conclusion from the high-speed railway study ofchina,so a completely harmonized method is given. Safe coefficients of design loadare used in the harmonized method that can make the implicit safe reservs for thedesign load visualized.The deformation control of subgrade is one Of critical factors that guarantee thetrack regularity unfor the normal status. The two embankments are selected from thesaturated soft clay area and their permanent and resilient deformations are calculatedaccording to the calculating model established. The comparison between thecalculating results and the site measurements is discussed in details. Influence scopeImprvemen of the M for cOmPOnbo ~ and vehicle’ quaitycompanng with the strict od irregularity Inanagnent and mainienance standardresulted in the dibo of the load boformedon and .distribution thrOUgh edtw betwee the highrpeed railWay and regUlar one. Based on a lot of sitemeasurem together with thoorecal analySS, hOw the vwhod fOrCes twfbnnthrowi the traCk StrUthe and its Prinops are studied. The tw rerponses ofthe od StrUde caused by high-Seed cars and locoInOthes can’t be negleCte, sothe additional dynamic theses of SUb~ are analpe accordin tO the coUPlin~c chcs.Man hors are the -- for the changr Ofed load, taking the vefocityof vehicles as thch -- Paramfor is suha1e from the expeence. MethdfOr calculatin the SyntheSbo wtc addional coefficient is detennind by thendaic analySs of the she exPeriInental data.Accondng to the ~c reSPOnSe analyS8 of od StrUCtUr, the conctheion ismad tba the od StrUCtUr i8 in the elastic work StatUS Unde ~c load CauSedby cars and locomOthes. W the conCluson as for, a twforon anddiWon mode for the vwhcal forCeS wt the tieS and bailaSt is est8blished.cOmParison betWeen the calculating results based on the model and the site-- bo tbat the model establisb can rebo the actual work statUS ofed bo ~. In de to bo the ededow coemcients are ~ torpe ds ~ stresses aiOn the bo or ~ by nd loatca- trr veta8 at the locatri unta ran ana - or sutr~.The deSgn foad for the COInPOned Of the od strutri is not COOMwith eaCh otber aCCOwi tO the COncha bo tbe highW

  • 【分类号】U211.4;U213.1
  • 【被引频次】36
  • 【下载频次】2154
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