Study On The Vertical Load Transmision Through The Track Structure And The Characteristics Of Subgrade Dynamic Strsses

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...