Application of Newmark_β and Characteristic Methods to Analysis of Response of Pile-Soil System to Impact Loading

摘要

In this paper, the pile-soil system is simplified into one dimensional problem, pile body is regarded as a rod. The interaction between pile and soil on the shaft is modeled by a plastic slider, spring, and dashpot. The shear action between pile toe and soil is also modeled by a plastic slider, spring, and dashpot, while radiation of dilation wave at toe is simulated by a spring, dashpot, and mass block. The interaction between hammer and pile top is modeled by a free falling mass, spring and dashpot in parallel. The motion equations of the mass-spring-dashpot system in the models is solved by Newmark_β method, while propagation of stress wave along pile body is calculated by characteristic equation method. Using two boundary conditions, response of pile-soil system to hammer impacting can be obtained. Effects of some parameters on response of pile top can be simulated by this method, the method can be also applied to more complex models. The results from simulations agree well with measured results.