Research On Bearing Characteristics Of CFG Pile Composite Foundation

With the development of high-rise buildings and diversification,the requirements for the bearing capacity of the foundation gradually increase,and the proportion of the foundation treatment cost in the project cost is relatively large.CFG pile composite foundation treatment technology has been widely used because of its wide application range,outstanding bearing performance and low engineering cost.Based on a practical project in handan,this paper studies CFG pile composite foundation from theoretical calculation,numerical simulation and field test.The main research conclusions are as follows:(1)The bearing mechanism and failure mode of CFG pile composite foundation are elaborated in detail,and the influencing factors of its bearing capacity and settlement are analyzed.The characteristic value of bearing capacity of CFG pile composite foundation is 263 kPa and the settlement is 71.81 mm.(2)According to the actual engineering geological conditions,the finite element software ABAQUS was used to simulate and analyze the CFG pile composite foundation.The influence of cushion thickness,cushion modulus,pile length and pile modulus on the bearing capacity of CFG pile composite foundation was studied.The research shows that the thickness of mattress cushion has an obvious regulating effect on the load-sharing ratio within the range of 200mm-250 mm.When the mattress cushion modulus is large,the further increasing modulus will weaken the regulating effect on the settlement,and the length of pile body will have a great influence on the settlement of composite foundation.When the pile body modulus is small,increasing the pile body modulus can reduce the settlement.(3)The vertical compressive bearing capacity of single pile and the bearing capacity of CFG pile composite foundation were tested by field sampling test of single pile static load and load sampling test of single pile composite foundation.The research methods and conclusions of this paper can provide some reference for the design of CFG pile composite foundation.