The3D Finite Element Numerical Simulation On The Characteristics Of Negative Skin Friction For Pile Groups Under Surface Load

From the negative friction was proposed so far, in less than one hundred years,domestic and foreign scholars on the negative friction resistance of pile foundation andpile–soil interaction has been carried out to study the calculation of a large number of fieldtest, model test, theory analysis and numerical, and achieved certain results. Based on thesummary of the previous research results, in view of the Surface Load piles negativefriction characteristics are investigated by numerical simulation analysis, Main contents ofthis thesis are organized as follows:1．In this paper explains the concept of negative friction of pile foundation, the causesand harm, reduce the negative friction of pile foundation measures and regulations onnegative friction in our specification, and the negative skin friction of pile foundationresearch from the four aspects of the summary and the summary, to understand the currentresearch status and the negative skin friction of pile foundation some problems, whichdefined the direction of the research.2．By using the ANSYS finite element analysis software, the constitutive relation ofthe selected pile and soil, and considering pile-soil contact problem of setting, theestablishment of three-dimensional finite element pile-soil model, using the results ofnumerical analysis and field test results and indoor model test results were compared,verified the rationality of three-dimensional finite element model of pile groups.3．Based on the finite element model, the ground load level, load on pile top grade,ground treatment and pile top load applies load sequence, pile–soil friction and the pilespacing on negative skin friction and negative friction resistance of pile groups effect isanalyzed, obtain valuable conclusions some regularity.4．Elaborated the theory calculation formula of pile negative friction resistance, theuse of based on limit equilibrium principle under the action of negative skin frictionresistance of pile group effect coefficient method of theory calculation, the threeengineering examples are calculated, the group of pile position in the pile group effectcoefficient of piles, the calculated results with measured results and the analysis of thenumerical simulation results were compared, the calculated results and the numericalsimulation results are in good agreement with the test result.