Study Of Settlement Properties Of Retaining Wall, CFG Composite Foundation Of WuQing Section On Beijing-Tianjin Intercity Railway

The Beijing-Tianjin inter-city railway system is the first passenger line opened in China with a speed capability of 350km/h. The railway system uses ballast-less track and post-construction settlement has to be less than 15mm. CFG-pile composite foundations are used. The present study examines in detail the post-construction settlement of the GFG-pile composite foundation in the Wuqing section that was designed to save land and conserve existing buildings. No in-depth study was found in domestic or foreign research which detailed the design or structural parameters for retaining walls based on CFG piles. In the present study, detailed calculations are presented on buttressed retaining walls and composite foundations. On-site inspection was conducted on the composite foundation in Wuqing section with mathematical treatments assisted by the MIDAS/GTS application. Data were collected on strength, length and sand/gravel cushion layer of the CFG pile as well as the strength and length of the foundation of the retaining walls. Comparisons are made among the data and the different slopes of the composite foundation with the final finding that the retaining wall CFG piles did resist, to a certain degree, post-construction settlement. Adjustment of the length of piles proved to be the most effective measure to reduce post-construction settlement.