Study On Characteristics Of Bearing And Deformation Of Composite Foundation For High-speed Railway CFG Pile(with Pile Caps)

Nowadays, CFG pile composite foundation is widely used in the soft soill andcollapsible loess foundation treatment of the high-speed railway. At present, research on theforce and working properties of CFG pile composite foundation under rigid foundation hasbeen made a relatively complete theoretical system and method of calculation, However, themechanism and working properties of CFG pile composite foundation under flexiblefoundation is not really perfect and far behind the practical application of engineering, CFGpile composite foundation under embankment flexible loads of work by different mechanismsfrom composite foundation under rigid foundation, Structure selection, design and calculationof theory and under different geological conditions of the construction process for furtherstudy. Existing research results is not comprehensive, the lack of engineering experience, It isnecessary to carry out the study of CFG pile composite foundation bearing and deformationcharacteristics. Firstly, make model test of CFG pile composite foundation under theembankment flexible Load. And then using the numerical method calculate the CFG pilecomposite foundation bearing and deformation characteristics. Finally, the model test andnumerical simulation from the law were compared. The main work is as follows:(1)Firstly, summary on three aspects of the theoretical study, numerical simulation,experimental study research and development status quo about CFG pile foundation under theembankment flexible load. Secondly, the problems about CFG pile composite foundationwere studied. By overview of the research, view to fully grasp the main issues and keytechnologies of CFG pile composite foundation, provides a premise for choosing this topic, aswell as research ideas and research methods.(2)Based on arrangement of CFG pile used in high-speed railway embankmentcomposite foundation, combined with similarity theory of model test design and develop theimplementation of the model test program.CFG pile (Hooded and not hooded) compositefoundation under the Embankment flexible load reinforcement effect of the natural foundationwere studied. Bearing, suspension without pile cap and composite foundation with pile cap,the embankment under flexible load pile-soil stress ratio of pile stress distribution, soilcommitments load, with the variation of load research and comparative analysis.(3) Based on the finite element analysis software MIDAS/GTS, Numerical simulationof several different conditions of CFG pile composite foundation stratified on theembankment fill construction process, CFG pile composite foundation bearing and settlementcharacteristics were analyzed. And were compared with the model test results, the correctness of the finite element model was verified.