Research On Settlement Control And Calculation Method Of High-Filled Subgrade Of High-speed Railway

The high-speed railway subgrade is an important structure which can bear and transmit train dynamic load and ensure the safe operation of the train.According to the survey,the high fill subgrade of Beijing-Shanghai and Wuhan-Guangzhou high-speed railway is between 10 and 15 meters.As for how to ensure the construction quality of 20-meter-high fill subgrade and make the settlement after construction meet the code requirement there is no reference data and experience to solve these issues.In view of this,based on the project of Yunnan-Guizhou Railway,this paper firstly studied the construction technology of high fill subgrade,and then used FLAC3D numerical analysis software to verify the reliability of the construction process and the construction parameters were optimized on this basis.In addition,combined with field experiment,the distribution of stress and settlement of subgrade and foundation based on remote monitoring data were analyzed,the composite modulus method for calculating settlement of composite foundation and layerwise summation method has been improved,besides,the three point method and the exponential curve method are put forward to predict the settlement.Based on the results,the applicability of the two methods is verified by comparing the theoretically calculated results with the field tests and numerical analysis data.Finally,the dynamic response characteristics of the subgrade during operation under train loading were analyzed by numerical simulation software.Through the above research,this paper puts forward a set of High fill subgrade of high speed railway construction technology,the settlement calculation method of composite foundation,and the settlement prediction of embankment and foundation were obtained.Research results provide data and theoretical reference method for high fill subgrade.