动力打桩一维波动方程的改进及其工程应用

Apply of improved wave equation method to practical ocean piling engineering

对桩的可打入性进行准确的分析和预测是打桩施工的关键环节,同时也关系到整个工程的进度与成败。近年来,在海洋工程和港口工程中都出现了大直径、超长桩,由于这种桩的重量大对桩的可打入性有显著影响,考虑桩身自重和桩周土阻力,对打桩分析的一维应力波动方程进行改进、推导。采用有限差分法求解波动方程,编制计算程序结合实际工程进行打桩分析,分析结果与实测数据吻合较好,表明经改进的动力打桩一维波动方程能很好的预测桩的可打入性及打桩过程中桩身应力分布情况。

To predict the drivability of piles accurately plays an important role in piling engineering. More and more large diameter and over-length piles have been adopted in the port and ocean engineerings recently. The dead-weight of this kind of pile has dramatic influence on the pile drivability. Introducing the self weight of the pile and the soils resistance around pile into one-dimensional stress wave equation will improve the analyzing accuracy of pile drivability. The wave equation has been modified based on the proposed model. The difference method is adopted in solving the improved wave equation and a calculation program has been developed. The presented method has been applied to a practical piling engineering. The calculated results agree well with the observed data. The analyzing results show that the presented method can predict the pile drivability and the stress distribution along the pile accurately.