Simulation Analysis Of The Sediment Effect In Pile Dynamic Testing

The pile bottom sediment, as a common quality problem in the process of pile foundation construction, will reduce the pile foundation's bearing capacity and increase the construction's subsidence. So far, there are lack of system analysis and theoretical summary about the differences in the piles' dynamic test signal made by the pile bottom sediment. This thesis has done some simulation analysis to this question with the aid of the finite element software, and then summarized some rules and suggestions that can be used in the project example.In the thesis, the theoretical analysis on the pulse wave in pile bottom sediment has first been carried on, and the theoretical solution without soil is obtained. Then the model of the pile-soil system has been established by using the explicit dynamic analyzing program LS-DYNA. Through the comparative analysis of the model with soil and the one without soil, the soil's influence to the piles' dynamic testing signal is summarized. According to the pile bottom sediment response in the piles' dynamic test signal, this thesis has mainly conducted the simulation research on two aspects: First, discussing the variation of the piles' dynamic test signal when the strength and thickness of pile bottom sediment change, and contrasting with the theoretical solution; Second, discussing the variation of the piles' dynamic testing signal when the pulse amplitude and pulse width of impact force change, from which some impacting methods are suggested. Finally, the conclusions are confirmed by the project example.In this thesis, the influence of pile bottom sediment to the pile dynamic test signal has been studied with in-depth simulation research, and the conclusions summarized have soma theoretical and practical significance.