Study On Cause Analysis And Treatment Measures For Subgrade Deviation Of One Section Of Beijing-guangzhou High-speed Railway

High-speed railway has become a common mode of transportation for people and high-speed railway subgrade is the foundation of train and upper structure,the stability of the subgrade affects the smooth running of the train,how to ensure the stability of subgrade has become an important research topic.So in this paper,the mechanism and law of displacement settlement of high-speed railway subgrade are studied and discussed through field practice.Based on the practical engineering of section k1609+720—k1609+820 of Beijing-Guangzhou high-speed railway and establish the three-dimensional finite element model of subgrade,analyzes the deformation mechanism of high-speed railway subgrade and the factors that affect the stability of subgrade are analyzed,the deformation law of subgrade under different conditions is obtained,the type selection roadbed reinforcement is analyzed systematically by the combination of quantitative and qualitative.The main work ia as follows:(1)This paper analyzes the monitoring data of roadbed disease and the project rectifying deviation scheme of k1609 section of Beijing-Guangzhou high-speed railway,based on the monitoring results and field investigation,collates and analyzes the data of high-speed railway roadbed deviation settlement.(2)Based on the field investigation,monitoring results and numerical analysis,the deformation characteristics of subgrade under the action of water level change and load are analyzed,discuss the cause and mechanism of subgrade settlement and deviation.(3)The time-history analysis of the subgrade model is carried out,the curves of the maximum vertical and lateral displacement with time during the one-time travel of the train through the roadbed section are obtained,the long-term settlement of subgrade is calculated.(4)The influence of four conditions(different train speed,different bed surface thickness,different bed bottom thickness and different moving mode)on the deformation of high-speed railway embankment is simulated by numerical analysis software.Based on the research results of similar projects at home and abroad and relevant high-speed railway specifications,the control standard of subgrade deflection is proposed.(5)Aiming at the problem of type selection of roadbed reinforcement,this paper systematically analyzes the selection of roadbed reinforcement type by using analytic hierarchy process(AHP)and establishes the comprehensive evaluation index system of reinforcement method,the optimization model is established by matlab software programming and the corresponding weights of the three schemes are calculated,determine the optimal reinforcement method.