Observation Analysis And Renovation Of Subgrade Settlement For Intercity Railway

Taking Zhengzhou-Jiaozuo intercity railway as the engineering background,the characteristics of ballasted track structure and the physical and mechanical properties of granular ballast bed is introduced in the paper.And the calculation model of cumulative subsidence provides a theoretical basis for the study of subgrade settlement.Then,the technical requirements for post-construction settlement of ballasted track subgrade of intercity railway is summarized.The Essentials of subgrade filling for intercity railway is expounded.Compaction standards and settlement control requirements are obtained,and the settlement mechanism of intercity railway subgrade is analyzed.It is concluded that the filling requirements and compaction standards of intercity railway subgrade have a direct impact on the size of subgrade settlement and deformation.When subgrade construction is not up to standard or in bad condition,the proportion of subgrade settlement in track settlement will increase.According to the hydrogeology,surface environment,general situation of roadbed design and evaluation of Zhengzhou-Jiaozuo intercity railway line,the method and requirement of roadbed settlement observation for Zhengzhou-Jiaozuo intercity railway are determined,and the subgrade settlement is checked and calculated by stratified summation method.According to the characteristics of settlement and deformation of Zhengzhou-Jiaozuo intercity railway project,the observation data of settlement and deformation of Zhengzhou-Jiaozuo intercity railway subgrade are analyzed in depth.The section data of Zhengzhou-Jiaozuo intercity railway are selected as the analysis object.To predict the settlement trend of the settlement,the settlement data of settlement area are regressively analyzed by means of exponential method and hyperbolic curve fitting.According to the site conditions and construction conditions of roadbed settlement,the flower tube grouting method is used to reinforce the settlement deformation of roadbed.Firstly,the grouting technological test is carried out to obtain the grouting parameters,such as grouting pressure,grouting quantity and grouting diffusion radius.Secondly,The flower tube grouting drilling hole is arranged reasonably and the grouting quantity is calculated.Finally,the grouting flow is strictly followed.During the grouting process,attention should be paid to controlling the pressure and ensuring the grouting effect.After grouting,the observation data of roadbed settlement are analyzed.The regression analysis of settlement data of subsidence section is carried out by means of exponential method and hyperbolic curve fitting.And the settlement trend is predicted.Then,for the further determined of the grouting effect,the field geophysical nondestructive testing is used to detect the abnormal shape of roadbed filling density,concealed cavity and water bag.Which providing a reference for other similar railway subgrade settlement treatment and understanding.