Numerical Simulation On Nonlinear Dynamical Behavior Of Single Pile

Pile foundation being a kind of old and traditional foundation form of building is in the important position in engineering development. At least millions of piles on average are used every year, costing about 25 percent of the whole engineering in our country. The pile foundation is extensively used in high-rise building, railway bridge, nuclear power stations , marine platform, coast dock and large dynamical machine foundation, because its loading is high and settlement is small . The pile foundation of buildings near sea and above sea under hard dynamic loads gets to nonlinear state and endangers buildings. Therefore, it is necessary to develop the research of this respect.This thesis utilize nonlinear dynamics principle, as under axial force, the nonlinear model of single pile is analyze, and find out the major factors in the behavior of single pile under axial force. The organic combination of theory's analysis and numerical value simulation can prove the reasonability of theory, may also confirm the value simulation reliability.The research and unique feature are as follows:(1) Summering the current study of the pile foundation under nonlinear loads in the world. Having introduced of the basis knowledge of nonlinear dynamics, having especially get out the general feature of chaos and the major methods for predicting the occurrence of chaos, and research the study of the mathematic method of single pile under nonlinear loads.(2) Though the timing-translocation graph Poincare graph power chart judgechaos, summering the regulation of duffing equation emerging chaos. Seek for a good way to solute the nonline problem and give out some beneficial conclusions.(3) Deducing the vibration model of nonlinear dynamic of the single pileunder axial difference method. The time histories of a single pole is shown in a three-dimensional mesh figure. The theoretical response correlates well with dynamic testing of an engineering pile by thereflective wave method.(4) The integro-partial-differential equation is simplified to partial-differential equation by using the Galerkin method, making matlab programs by the theory of vary-step Runge-Kutta, then, gets some data documents which are used to draw graphs.(5) Considering the nonlinear dynamics behavior of the single pile underthe axial force and using the latest software matlab to analyses and draw, the author gets about 50 pieces of graphs, for example, the timing curve, phase graph, Poincare graph.