Experimental Comparison Study On Behavior Of Settlement Between RAM-Compacted Piles With Bearing Base And CFG Pile In High Speed Railway

In recent years, with the rapid development of high speed railway, especially the extensive use of Non-ballastless Track, the settlement and deformation of offline engineering needs more and more strict requirements (post-construction settlement aren’t more than15mm). When high-speed railway pass adverse foundation such soft soil, how to control the deformation and settlement of offline engineering is to become a big problem. In the past, most of high speed railway used bridge replace subgrade to achieve a better way for controlling the purpose of the settlement and deformation. Until recent years, with the composite foundation reinforcement technology development, such as CFG pile composite foundation, is widely used in high speed railway embankment reinforcement. Even so, the development of other forms of composite foundation reinforcement technology still has the very vital significance.This paper on the basis of previous studies, relying on the beijing-shanghai high-speed railway composite foundation technology of Ram-compacted piles with bearing base and CFG Pile test, through the two rigid pile composite foundation compression characteristics of the contrast test and numerical simulation, used the mature theory and practice research of CFG pile, to analysis the foundation surface subsidence, Consolidation Deformation Property of Reinforced area soil,the deformation characteristics underlying soil of Ram-compacted piles with bearing base. This article concluded:(1) The field test results show that:in the embankment load, Ram-compacted piles with bearing base and CFG pile composite foundation settlement with the change of load and time are consistent. According to the size of the subsidence rate can be divided into rapidly development stage, stage of development and basic stability; Due to the relatively shallow depth of Ram-compacted piles with bearing base, the foundation total settlement, thickness of compressible and the time required to stability are larger than CFG pile composite foundation.(2) The results comparison between the finite element analysis and the field test show that:the change rule is consistent, the final settlement, the main thickness of compressible and the load sharing ratio are close to the measured value; The use of all secant modulus and material parameter in finite element analysis can reflect the physical truth; The modulus of compressibility according to the revised depth can correspond the local soil compressibility. This paper of numerical computation model can be used for further optimization design.