The Research On Tangential Stiffness Fitting In Pile Soil System Contact Surface

The pile soil contact problem is always one of the difficult problems in civil engineering. The value of the contact surface parameters gives many uncertain factors to the analysis of simulation results. And as the important index to the contact surface parameters, shear stiffness is mainly influenced on the relative slip hazards between pile and soil. For the sake of studying this aspect of the problem, lead into the exoterica of Mohr Coulomb and theory of particle flow, and use the method of combining experiment with the finite difference method.To explore the method of selecting contact surface tangential stiffness value. The main work can be summarized as the following:(1) Summarize the research present situation of pile soil contact problem.Sum up the various tests and numerical simulation results. Further analysis of mechanical conduct of pile soil contact surface element can lay the theoretical foundation for the study on shear stiffness.(2)Using Mohr Coulomb and theory of particle flow to analyse the influence factors of pile soil contact surface tangential stiffness. Determine the factors that can be used for calculating quantitatively, and conduce the classification processing.(3)Combined with the engineering geological data and test results of indoor pile-soil experiment, to analyse the change law of pile lateral friction resistance under vertical load. Regression analysis is used to explore the model that reflect the relationship between tangential contact stiffness and external factors.Creat the mathematical relationship between tangential stiffness and the two types of factors. Through the Matlab numerical analysis software to carry on three-dimensional surface fitting,and determine the reasonable magnitude of tangential stiffness.To provide the reference for choosing method of pile soil contact surface parameters.(4)The establishment of pile-soil coupling system of three dimensional model, to analyse the effect of shear contact stiffness of pile and soil system performance by finite difference method. And verify the rationality and feasibility of the numerical description method.