Steady state harmonic response of nonlinear soil-structure interaction problems is addressed in this paper. Due to well-known stiffness degradation phenomenon, the steady-state study is referred to small-medium strain condition whereas no significant pore water pressure change is observed (e.g. clayey soils and sands in drained conditions). A novel cyclic hysteretic model based on the Preisach formalism is proposed to describe the cyclic behavior of soil-foundation interaction. Through a harmonic balance procedure, furthermore, the steady state response of nonlinear soil-structure interaction problems is determined. Equivalent amplitude-dependent stiffness and damping have been derived in closed form to reliably describe the nonlinear soil-structure interaction phenomenon. Those expressions are function of the elastic foundation soil stiffness, the maximum attainable horizontal force and the moment capacity of the foundation. Furthermore, handy expressions of the equivalent fundamental period and damping, also dependent from the level of the excitation, are also derived. The proposed hysteretic model, moreover, has the advantage to be easily calibrated to match the modulus reduction and damping curves determined either from numerical or experimental tests. Numerical applications and comparisons with more advanced models and experimental data available in literature are also presented.

本文讨论了非线性土-结构相互作用问题的稳态谐波响应。由于众所周知的刚度降低现象，稳态研究被称为中小应变条件，而未观察到明显的孔隙水压力变化（例如，排水条件下的黏土和沙子）。提出了一种基于Preisach形式主义的新型循环滞回模型，描述了土-基础相互作用的循环行为。此外，通过谐波平衡程序，确定了非线性土-结构相互作用问题的稳态响应。以封闭形式导出了等效振幅依赖的刚度和阻尼，以可靠地描述非线性的土-结构相互作用现象。这些表达式是弹性地基土刚度的函数，最大可获得的水平力和基础的弯矩能力。此外，还得出了等效基本周期和阻尼的简便表达式，该表达式也取决于激励水平。此外，所提出的磁滞模型具有易于校准的优势，以匹配从数值或实验测试确定的模量减小和阻尼曲线。还介绍了数值应用以及与更高级模型的比较以及文献中提供的实验数据。具有易于校准的优势，以匹配从数值或实验测试确定的模量降低和阻尼曲线。还介绍了数值应用以及与更高级模型的比较以及文献中提供的实验数据。具有易于校准的优势，以匹配从数值或实验测试确定的模量降低和阻尼曲线。还介绍了数值应用以及与更高级模型的比较以及文献中提供的实验数据。