Research On The CFG Pile Composite Foundation Bearing Mechanism And The Experiment

With the development of urban construction, modern architecture is given priority to with high-level, and its load-bearing characteristics of foundation and settlement deformation are more strict. CFG pile composite foundation has the characteristics of fast construction speed, low cost and the great reinforcement effects,so it is quickly widely used in foundation treatment field.but its related theories are not yet mature and the design methods have some defects,so it needs further research. This paper, taking a high-rise residential building shangluo prefecture as the engineering background,research CFG pile composite foundation bearing mechanism and carries on the optimization design.This paper carries on the research analysis from the following aspects:(1) The CFG pile composite foundation reinforcement mechanism, failure mode,negative friction resistance are analyzed in detail. The CFG pile composite foundation bearing capacity and settlement of the various calculation methods respectively are discussed in this paper and analyze the advantages and disadvantages of each kind of calculation methods and its applications.(2) The CFG pile composite foundation of 3D solid model is established by finite element software ABAQUS.Qualitative analysis of the thickness and modulus of cushion, pile length, pile modulus and other factors in the influence of settlement,pile-soil stress ratio and the pile axial stress by using this model, the corresponding rules are concluded. According to the geological conditions of Shangluo area, this paper uses the method of numerical analysis and the empirical formula of bearing capacity of combination to analyze the CFG pile composite foundation of soil between pilescoefficient of exertion.Then conclude the range of the coefficient and provide reference for the design of foundation engineering in the area.(3) This paper presents a new optimal design method of CFG pile composite foundation which uses empirical formula to calculate the bearing capacity and gets design scheme satisfied the requirements of bearing capacity. Then, using the method of numerical analysis verify the scheme of settlement whether it can be satisfied by the design requirements.Finally we choose the optimal design scheme.(4)Through the results of field testing of a high-rise residential building of CFG pile composite foundation in Shangluo area,we can verify the rationality of the finite element model. Test results show that the single pile and the bearing capacity of the composite foundation have some optimization space and optimize the original design scheme.