Bearing Mechanism Study And Finite Element Analysis On CFG-pile Composite Foundation

During the civil engineering construction of highway, railway, irrigation works, building engineering and airports, soft clay foundation are usually encountered. CFG-pile composite foundation is an effective and popular method for consolidating soft ground which is applied more and more widely in recent years. So the research on the bearing mechanism of CFG piles composite foundation is theoretically and practically important.Deformation compatibility equation has been established in this thesis. According to the static equilibrium condition, the formula for calculating reasonable thickness of cushion has been deduced. The suitable cushion materials style has been suggested from comprehensively considering the enhancing load bearings of CFG-pile, reducing settlement and cushion action mechanism. By contrastively analyze the various bearing capacity formulas of CFG-pile composite foundation, and educed the improved formula. The thesis elicits the design method of distance of piles controlled by the composite foundation bearing capacity. The formulas of distance of piles disposed in rectangle and triangle are also have been educed. Various schemes have been calculated by utility of ABAQUS analyzing software, by analyze the results, conclusions about pile length, thickness of cushion and rate of area of CFG-pile influence on bearing capacity and settlement of CFG-pile composite foundation have been derived. From a scheme, also educed pile-soil relative displacements, pile shaft skin friction, the earth pressure on retaining pile and stress and displacement of the soil of the end of pile.In conclusion,this thesis obtained the basic law field of stress and displacement of CFG-pile composite foundation and analyzed the various factors that influence on bearing capacity and displacement of CFG-pile composite foundation. All these conclusions can offer theoretical arguments in optimization design of CFG-pile composite foundation.