弹塑性p–y模型及非线性地基梁的增量有限元法

Elasto-plastic p-y model and incremental finite element method for beams on nonlinear foundation

在水平受荷桩基的分析与计算中,p–y曲线法是应用较为广泛的方法之一。在边界面弹塑性理论的框架内,建立了一个p–y模型。与传统的p–y曲线比较,该模型能通过不同的参数取值,模拟不同非线性特性的p–y关系,并能模拟往复荷载作用下的桩土相互作用。同时采用非线性地基梁的增量有限元法,结合提出的弹塑性p–y模型,编制了有限元分析程序,对单调和往复水平荷载作用下的桩土系统进行实例分析,结果表明该方法能有效的模拟水平荷载作用下的桩基非线性响应。

The p-y curve method is one of the most commonly used approaches in the analysis and design of piles under horizontal loadings. A p-y model is proposed within the framework of bounding surface elasto-plastic theory. In comparison with the traditional p-y curves, the model can simulate p-y relationships with different degrees of nonlinearity by choosing appropriate values for the model parameters, and can also simulate the soil-pile interaction under cyclic loadings. By adopting the incremental finite element method for beams on nonlinear foundation incorporating the proposed elasto-plastic p-y model, a finite element program is formulated. Soil-pile systems in the field or in the laboratory tests under monotonic or cyclic horizontal loadings are analyzed by use of the finite element program. By comparing the calculated and measured results, the capacity of the method and the proposed elasto-plastic p-y model in modeling the nonlinear response of the piles is demonstrated.