Numerical Analysis Of High-Frequency Vibration Pile For Small Prefabricated Pipe Pile

Small prefabricated piles are the combination of micro piles and high strength prestressed pipe piles,with the advantages of miniaturization and quick construction.The high-frequency hydraulic vibration pile has the advantages of small vibration and low noise,fast construction,wide geological range and small damage to the prefabricated pile.The engineering method has been widely used in the engineering field.However,the construction process mechanism is lack of research.In this paper,the Coupled Euler-Lagrangian analysis method(CEL)is used to simulate the high-frequency vibration process of micro-pipe pile,and the mechanism and trait of high-frequency vibration pile are discussed.Which is conducive to improving the construction technology and design methods.Firstly,aiming at the characteristics of large deformation of high-frequency vibration pile,the conventional large-deformation numerical analysis method has convergence problem,and the large-deformation vibration pile is simulated by coupling Euler-Lagrangian numerical analysis method(CEL),The exciting force loading method simulates the high frequency penetration process of single pile.The interaction of pile and soil in the process of penetration of small prefabricated piles is studied,and the rationality of the model is verified by theoretical analysis.Then the influence of pile penetration on pile soil is analyzed in detail,including the squeezing stress,squeezing displacement,pore water pressure and soil plug in the process of single pile penetration.And the influence of parameters such as soil modulus,pile diameter and piling method on soil plug effect are analyzed.The results show that the pile in the high frequency vibration pile sinks gradually in the fluctuation,and the radial squeezing stress and the squeezing displacement increase with the depth of the pile.The surface displacement is mainly dominated by the uplift,and decreases with the increase of the radial distance.The squeezing displacement of the deep soil increases with the horizontal displacement of the pile.Based on the analysis of the high frequency penetration process of single pile,the high frequency penetration process of group piles are simulated.The interaction between piles and soil during pile penetration is studied,and pile penetration rate,the change of squeezing soil pressure,squeezing displacement during pile penetration is analyzed.In addition,the influence of pile parameters,such as pile diameter pile spacing and piling sequence on the squeezing displacement of group pile are also analyzed.The results show that,in the high-frequency vibration process,after the pile into the pile will cause the first pile to float,and increase squeeze displacement around pile.Pile diameter,pile spacing,piling sequence are on the pile into the traits influences.