The Study On The Reasonable Spacing Arrangement Of CFG Piles For The Treatment Of Soft Ground In High-Speed Railway

Some main achievements of this thesis are based on the Dacheng railway reconstruction project, which study on the comprehensive construction technology and standard of 200～250km per hour passenger and freight mixed railway. Having done some researches, which are the locale testing, centrifuge testing and analysis using software programme SIGMA/W.The locale testing indicates that, the soft ground composited with CFG piles can meet the requirement of design. The settlement of the surface of the under grade increased as the increasement of the load, but the sum settlement can still fulfill the requirement. The x-displacement also had great development, which was steady when the height of the under grade meet the design requirement.The centrifuge testing was done for simulating the typical transect of the soft ground composited with CFG piles. There are five groups of centrifuge testing with different distance between each pile. Some research are did on the stress and strain of the under grade, foundation and CFG piles. The testing indicate that, the distance between each pile strongly impact the steady of the foundation.The SIGMA/W programme is used to simulate the stress and settlement of the soft ground composited with CFG piles, and analyze the effect of the restrength with different distance of each pile. The calculating indicate that, the settlement of the under grade and the strength of the CFG piles can meet the requirement of the criterion, when the distance of each pile≤2.5m.According to the field test and theory calculation ,it can be obtained that using the three-four times CFG spacing(1.5～2.0m) for the treatment of soft base can statisfied the specifacation requirement ,and save engeeing cost 1/4. so this design shows significant economic benifit, and have vigorus extension in future similar engeering.