基于桩-土非线性动力分析改进的Winkler模型

Adaptedd Winkler model based on nonlinear dynamic analysis of soil-pile

一种数值模型用来研究地震作用下桩基础反应,在Winkler模型基础上,考虑了桩的柔性与能量耗散及辐射。模型用来研究桩-土-结构共同作用分析,包括桩土非线性效应,考虑桩土体系非线性及其在强震作用下会产生大的变形,桩采用材料与几何非线性的梁-柱元相同,而土体假想为沿桩长段均匀的非线性弹簧-阻尼器,进而采用修正的Ramberg-Osgood模型。利用剪切模量与阻尼一个关系导得土的阻尼。为了模拟土中辐射阻尼效应,桩与土采用粘性阻尼器连接。模型同文献中的振动台测试对比表明,该模型与测试结果较吻合,进而为强震作用下桩土分析提供一种数值分析方法。

A numerical model to study the seismic response of pile foundation, it is based on Winkler model,takes into account both pile flexibility and energy dissipation and radiation. The model is applied to study the influence of soil-pile-structure interaction on the response of structures,including nonlinear pile-soil effects. To incorporate nonlinearities in the soil-pile system might arise from large deformations under severe earthquake loading, the piles＇ material and geometry using non-linear the beam-column element, while the soil is idealized by nonlinear springs and dashpots uniformly attached to the piles along their length. For the soli springs, a modified Ramberg-Osgood model is employed; for the material damping of the soil, a simple relationship between the shear modulus and damping is utilized. To simulate the radiation damping effect in the soil, viscous dampers are attached to the pile. Model is compared with the literature of shaking table tests,indicating that the model agrees with the test results, and provides a numerical analysis for the strong motion of pile-soil analysis methods.