Study On Piling Effects Of Prestressed Concrete Tapered Pipe Pile

Based on the analysis and summary of the tapered pile and the prestressed concrete tapered pipe pile,a new soft soil foundation reinforcement technology—the prestressed concrete wedge pipe pile is put forward by the research group.In this paper,model test and numerical simulation are applied to systematically study the piling effects of prestressed concrete papered pipe pile.The main characteristics contribution of the dissertation is as follows:?1?Through the model test of static piling of equal thickness tapered pipe pile,unequal wall thickness tabered pipe pile and uniform pipe pile,the laws of variation of radial displacement of soil surrounding pile,vertical displacement of soil surrounding pile and piling presure with piling depth increasing had been obtained.By comparing and analyzing the experimental data of piling of three piles,the influence of the tapered outer wall and the tapered inner wall on the piling pressure and the displacement on the surface of soil surrounding the piles had been obtained.?2?Based on the PFC^2D,The correlation between particle mesoscopic parameters and shear strength parameters of cohesive soil and the effect of changes of particle mesoscopic parameters on the strength of samples are studied.The calibration order of parameters is determined in the process of parameter calibration.And when the mesoscopic particle parameters change in a certain range,the range changes of shear strength parameters and strength of samples had also been certained.?3?Simulating static piling with PFC^2D,The piling pressure is basically the same with that of model test,which verifies the reliability of simulation.the variation laws of soil porosity and soil pressure and the displacement of deep soil around the pile in the pile sinking process are obtained by numerical simulation.The research results in this dissertation shows that:1)The tapered outer wall of the prestressed concrete tapered pipe pile can increase the piling pressure,and the tapered inner wall can not only increase the piling pressure,but also changes the regulation of the piling pressure.2)In the process of pile sinking,the changes of displacement,porosity and the pressure of soil of prestressed concrete tapered pipe pile are all greater than that of the prestressed concrete pipe pile.3)The contact modulus and the friction coefficient of balls are the main fine particle parameters that affect the cohesion and the internal friction angle of the material,which should be determined first In the calibration process of the mesoscopic particle parameters.