基于接触面弱化效应的横向受荷长桩非线性建模及动力学研究

项目名称： 基于接触面弱化效应的横向受荷长桩非线性建模及动力学研究

项目编号： No.11502072

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 马建军

作者单位： 河南科技大学

项目金额： 22万元

中文摘要： 由于土-结构相互作用及接触效应的复杂性和现有理论的局限性，桩基动力学研究中仍存在接触面效应不明确、非线性动力学机理不清晰等理论和技术难题，这些都严重限制了桩基的动力学设计及工程应用。针对这些亟待解决的科学问题和技术难点，本项目拟以典型的横向受荷长桩为对象，系统地研究桩基非线性动力学特性并评估土-结构接触弱化效应。首先，考虑土-结构相互作用、接触面弱化效应和几何非线性，利用动力学建模理论建立桩基的精细化动力学模型，并通过该模型全面分析其动力屈曲、共振激励响应、模态相互作用、分叉与混沌等非线性动力学行为；然后，基于桩基的非线性动力学特性，利用能量原理量化评估土-结构相互作用及接触弱化效应；最后，开展动力学模型实验，测试分析各种工况下桩基的动力响应，并对理论方法的准确性进行验证。本项目研究成果将丰富与发展非线性动力学及耦合动力学的理论与方法，最终达到基于非线性动力学理论指导桩基动力学设计的目标。

中文关键词： 桩基；土-结构相互作用；非线性振动；接触弱化；动力学实验

英文摘要： For the complexities of soil-structure interaction and contact effect, and the limitations of existing theories, there are some defects exist in the dynamics research of pile foundations, such as the effect of contact surface and the mechanism of nonlinear dynamics are ambiguities. Obviously, all these issues limit the engineering application and dynamic design of pile foundations. Targeting on these scientific and technical difficulties should be solved quickly, the present project selects a typical laterally loaded long pile as the study object, investigates the nonlinear dynamic characteristics of pile-soil interaction systems and evaluates the soil-structure contact weakening. Considering the effect of soil-structure interaction, the weakening phenomena of the contact surface between the pile and soil field and geometric nonlinearity, a refined dynamic model of pile foundation would be derived employed the dynamics modeling theory. And, the nonlinear dynamic behaviors of the system are examined by means of the dynamic buckling, resonant response, modal interaction and bifurcation and chaos. Then, based on the nonlinear dynamics of pile foundations, the evaluations of soil-structure interaction and contact weakening are revealed based on the energy principle, in the quantitative level. Finally, to validate the accuracy of the theoretical methods, the dynamic model experiment on test and analyze the dynamic response of pile foundation would be carried out, under various conditions. Overall, the results of the present project would enrich and develop the theories and methods of nonlinear dynamics and coupling dynamics, and the guidance of the dynamic design of pile foundations on the base of the nonlinear dynamics could be achieved.

英文关键词： Pile foundation;Soil-structure interaction;Nonlinear vibration;Contact weakening;Dynamic experiment