Monitoring and Simulation Analysis of Composite Foundations on Bearing Characteristics for a High-Speed Railway

The methods of geogrid reinforced and CFG pile-supported foundation is a new technique for foundation treatment developed in recent years. It is the first time to be applied in high-speed railway whose design speed is 350km/h. It consists of rigid piles, geogrids, cushion and soft soil foundation. The unity of pile, geogrid and soil bear the load together. Because of the soil arching effect, tensioned membrane effect and stress concentration. The composite foundation can not only restrict the side deformation of soft soil, but also give full play to the strength an the deformation properties of the soil, in order to effectively improve the strength of the soft soil foundation, reduce settlement of the soft foundation after reinforcement, short construction period and lower construction costs. In this paper, based on the test section of a high-speed railway line, experimental analysis and numerical simulation were used to study the action mechanism, the deformation rules and the stress distribution rules of the pile-net composite foundation.