Analysis On The Effect Of Pile-soil In Rigid Pile Composite Ground

For the deeper discovery of act mechanism of rigid pile composite ground, the analysis on the performance of pile-soil under rigid foundation with cushion or without cushion is systematical studied by means of the theoretical method and numerical method.Depending on both Boussinesq and Mindlin stress solution, the calculating formulae of the settlement of pile-soil under foregone pressure is proposed, which account the interaction of pile and surrounding soil. The effect of pile and surrounding soil in composite ground without cushion is deduced, and the solution is obtained by solving the equation group making use of the pile-soil settlement condition. Using VB computer language, the samples are calculated, and analysis on distribution of counter force of soil as well as comparison of load-settlement is presented.For the mechanism of rigid pile composite ground with cushion is different and more complex, basing on limit equilibrium theory, there is an analysis for the effect on pile-soil stress ratio mastered by the thickness of cushion on pile and internal friction angle of cushion, and a new formula is established. Depending on the pile-soil settlement formulae deduced above, the iterative calculating method for pile-soil stress ratio and optimize design method is put forward. The programs are written using VB computer language, and the samples are calculated and the effect influenced by the thickness and internal friction angle of cushion and the load value are concluded.Furthermore, using finite element computer program the simulation of the performance of rigid pile composite and analysis on the influence of the design parameter of cushion or pile is brought forward.The research results can answer well for the conclusion of work experience and in-situ test. The methods presented are useful for engineering design and construction.