Analysis On Composite Foundation Settlement Of High-Speed Railway

At present, the high-speed railway in China is in a period of rapid growth. High-speed railway construction has characteristics of heavy task, line long mileage, long span regional area etc according to high-speed railway building mid-term planning of "five vertical, six horizontal and seven lines" high-speed railway network. At the same time, we know that the high-speed operation standards of high-speed railway settlement control requirements are particularly high for the foundation. However our country region is vast, the weak foundation distribution is wide, a lot of high-speed railway constructions will appear in the soft ground area. So for the soft foundation treatment of high-speed railway construction, it is necessary to test and research theoretically. According to the experience of soft foundation treatment by composite foundation method (CFG composite foundation) based on completed high-speed railway. In this paper, relying on the the new passenger traffic only Cheng-Yu line DK96+384.111-DK96+475.00subgrade section, try to master the working characteristics of CFG pile in soft foundation treatment of high-speed railway especially the settlement analysis through combining experiment and numerical analysis method, The main contents of research:1、Overview basic information of the test site and test method. Based on the test researching and the analysis of the measured data, try to find some rules of the stress of pile top and the pile-soil, geogrid stress and composite foundation settlement.2、Finite element software named PLAXIS is used to simulate the CFG composite foundation of test point. With the test monitoring data, correctness and rationality of the finite element numerical simulation is verified.3、Analyzing some important parameters of the design such as:composite foundation of pile length, pile spacing, thickness of cushion on the settlement by using PLAXIS finite element method, optimize the composite foundation design.