Numerical modeling and simulation of pile in liquefiable soil
Numerical modeling and simulation of pile in liquefiable soil
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DOI：
10.1016/j.soildyn.2009.02.008
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发表时间：
2009-11
影响因子：
4
通讯作者：
Zhao Cheng;B. Jeremić
中科院分区：
文献类型：
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作者：
Zhao Cheng;B. Jeremić
本文提出了液化土中桩的数值模拟方法。建模依赖于采用验证的土骨架弹塑性材料模型，验证完全耦合的多孔介质(土骨架)-孔隙流体(水)动力有限元公式，以及有限元模型的详细荷载阶段。考虑组构变化的边界面弹塑性砂土模型用于模拟土体骨架，而完全耦合的动力非弹性公式(u-p-U)用于模拟土和水的位移和孔压。该模型从无桩土的零应力应变状态开始，然后施加自重，然后采用自重进行开挖和打桩，注重精确的阶段性加载。最后，先施加地震荷载，然后再施加时间，以驱散已形成的过剩孔压。共模拟了6个算例，模拟了不同的坡度、桩-柱的存在以及桩-柱体系的边界条件。提出了有趣和有用的结果，用于加深我们对土-桩-柱系统在液化过程中的行为(横向变形、桩钉效应、地面沉降)的理解。此外，对模型进行了详细的描述，强调了高保真建模工具的可用性和使用，以模拟液化土对土-结构体系的影响。
Presented in this paper is numerical methodology to model and simulate behavior of piles in liquefiable soils. Modeling relies on use of validated elasto-plastic material model for soil skeleton, verified fully coupled porous media (soil skeleton) – pore fluid (water) dynamic finite element formulation, and detailed load staging of FEM models. A bounding surface elastic–plastic sand model that accounts for fabric change is used to model soil skeleton, while a fully coupled, dynamic, inelastic formulation (u–p–U) is used to model soil and water displacement and pore water pressures. Much attention is paid to accurate staged loading of the models, which start from a zero state of stress and strain for a soil without a pile, followed by application of self-weight, then by excavation and pile installation with application of pile self-weighting. Finally, seismic loading is applied followed by time to dissipate excess pore pressures that have developed. A total of six cases were modeled and simulated varying slope inclination, presence of pile–column and boundary condition for pile–column system. Presented are interesting and useful results that are used to deepen our understanding of behavior of soil–pile–column systems during liquefaction (lateral deformations, pile pinning effect, ground settlement). Moreover, detailed description of modeling is used to emphasize the availability and use of high fidelity modeling tools for simulating effects of liquefied soil on soil–structure systems.