Dynamic Characterization of Shallow Foundations on Granular Soils

9320539 Pak这个项目的目的是从理论到实践，提高目前对土-地基动力相互作用的理解，重点关注嵌入粒状土壤中的浅层建筑基础。其目的是：(1)检验和描述现有的物理问题的解析和数值解的适用性；(2)进行彻底的参数研究，以阐明重要的地基和土参数对动力响应的影响；(3)通过校准，识别并使现有的相关理论适用于颗粒土条件；以及(4)发展更全面的解决方案和公式，以处理这类问题所固有的应力诱导的非均质土条件。为了实现这些目标，将在土工离心机上进行一系列基本的实验。研究的重点是确定在地震和随机荷载作用下，地基在竖向、水平和摇摆模式下的反应。特别注意建立一个关于以下因素的综合数据集：(I)基础尺寸；(Ii)基础静载；(Iii)由动力激励水平引起的非线性；(Iv)基础形状；(V)埋置；以及(Vi)固有参数和全局参数对动力响应的影响。除了为进一步的理论和数值发展提供急需的物理基础外，这项研究还将允许推导出直接的半经验关系，这对设计师来说可能是直接的价值。***

9320539 Pak The aim of this project is to improve the current understanding of dynamic soil-foundation interaction, from theory to practice, focusing on shallow building foundations embedded in granular soils. The objectives are to: (1) examine and delineate the applicability of existing analytical and numerical solutions to the physical problem, (2) perform thorough parametric studies to clarify the influence of important foundation and soil parameters on the dynamic response, (3) identify and adapt relevant existing theories to granular soil conditions by calibration, and (4) develop more comprehensive solutions and formulas to deal with the stress-induced heterogeneous soil conditions intrinsic to this class of problems. To achieve these goals, a fundamental series of experiments will be conducted on a geotechnical centrifuge. The interest is in determining the foundation response in vertical, horizontal, and rocking modes under earthquake and random loading. Particular attention is given to the development of a comprehensive data set on the effects of: (i) foundation size, (ii) static foundation load, (iii) nonlinearities due to dynamic excitation levels, (iv) foundation shape, (v) embedment, and (vi) intrinsic and global parameters on the dynamic response. In addition to furnishing the much-needed physical basis for further theoretical and numerical developments, this research will allow the derivation of direct semi-empirical relationships which can be of immediate value to designers. ***