Dynamic soil-pile interaction by random vibration methods
Dynamic soil-pile interaction by random vibration methods
复制标题
通过随机振动方法进行动态土-桩相互作用
DOI：
--
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
M. Fotouhi
中科院分区：
文献类型：
--
作者：
M. Fotouhi
动力地基相互作用是结构在地震、风、机器振动、车辆荷载和冲击等动力荷载作用下设计的重要考虑因素。这一重要性的一个原因是，土-结构相互作用（SSI）可能对土-基础-结构系统的动力响应产生不利影响。然而，目前土桩动力相互作用的理论和解决方案可能相当复杂，并且包含一些不确定的参数。此外，土-桩动力相互作用问题的一些方面难以准确表征，例如土性质的高度非均匀空间分布、土的非线性和应力依赖的力学响应、土-桩接触条件的变化以及非均匀介质中三维波传播的复杂性。尽管土桩动力相互作用的理论和实验研究取得了重大进展，但许多现有的简化方法和复杂的数值模型都不能准确地捕捉到实际多模态试验中观测到的响应。为了弥合土桩动力相互作用问题的现有理论和实验观测之间的知识差距，本研究在同一地点使用两个相同的h型桩进行了全尺寸动力现场试验，其中含有软粘土。一桩安装在天然土壤剖面中，另一桩部分嵌入改良的水泥土带中。研制了一种新型的伺服液压惯性激振器试验系统和模块化桩帽，利用随机振动技术对桩进行强制振动试验。在三种不同的测试配置下，采用安装在桩承台上的激振器对系统施加三种不同类型和强度的宽带激励。为
Dynamic soil-foundation interaction is an important consideration in the design of structures subjected to dynamic loads such as earthquakes, wind, machine vibration, vehicle loading, and impacts. One reason for this importance is that soil-structure interaction (SSI) can have detrimental effects on the dynamic response of soil-foundation-structure systems. However, present theories and solutions for dynamic soil-pile interaction can be quite complex and contain several parameters that are not known with a high degree of certainty. Additionally, several aspects of dynamic soil-pile interaction problems are difficult to characterize accurately, such as the highly-nonhomogeneous spatial distribution of soil properties, the nonlinear and stress-dependent mechanical response of soil, variable soil-pile contact conditions, and complexities of 3D wave propagation in nonhomogeneous media. Despite significant advancements in theoretical and experimental research on dynamic soil-pile interaction, many of the available simplified approaches as well as sophisticated numerical models fail to accurately capture the observed responses from realistic multi-modal experiments. To help bridge the knowledge-gap between existing theories and experimental observations for dynamic soil-pile interaction problems, a program of full-scale dynamic field tests were performed in this study using two identical H-piles at the same site containing soft clay. One pile was installed in the natural soil profile, and the other was partially embedded in an improved soil-cement zone. A new servo-hydraulic inertial shaker testing system and modular pile-cap were developed, then used to perform forced-vibration tests on the piles using random vibration techniques. Three different types and intensities of broadband excitation were applied to the system using the shaker installed on the pile cap in three different testing configurations. For the