大型渡槽考虑土-结构相互作用的动力分析

根据某大型渡槽采用桩基础的结构特点,采用集中弹簧模型考虑土－结构相互作用;渡槽槽身采用薄壁梁段单元进行离散,考虑了渡槽槽身开口薄壁结构的横向变扭耦合振动、约束扭转变表等结构自身特性;渡槽支架采用空间梁单元进行模拟。文章建立了大型渡槽的动力方程,对比计算了考虑土－结构相互作用与不考虑土－结构相互作用渡槽模态和地震响应的差异,计算结果表明：考虑土－结构相互作用后,虽然对大型渡槽的模态和地震应应有所影响     

桩-土-结构动力相互作用的线弹性地震反应分析

采用集中质量法(简化模型)，用ANSYS软件作为桩—土—结构动力相互作用分析的工具，建立了小震下钢筋混凝土剪切型结构考虑桩—土—结构动力相互作用效应的计算模型，进行了桩—土—结构相互作用线性体系的模态分析，研究了考虑桩—土—结构相互作用体系的自振特性；进行了小展下桩—土—结构相互作用体系弹性地震反应时程分析，研究了土—结构动力相互作用效应对结构地震反应的影响；得出如下结论；考虑桩—土—结构相互作用效应后，结构体系的自振特性及结构的地震反应将有所改变。     

平面剪切型结构考虑土—结构相互作用的地震反应分析

本文根据子结构法思想提出了相互作用体系在频域内的运动方程,同时应用波在连续介质中的传播理论和间接边界元法推导了格林影响函数,从而进一步推导了地基土的动力刚度系数。文中通过计算带埋置的刚性矩形基础的平面剪切型结构的地震动力响应,并与基底固定的计算结果作比较,得到了有意义的结论。     

土-结构动力相互作用研究综述

土与结构动力相互作用是当代力学领域的前沿性研究课题,具有很强的实践性。对土与结构动力相互作用的研究历史与现状进行了介绍,简要综述了当前土与结构动力相互作用的研究方法,重点介绍了目前关于土与结构动力相互作用问题中从无限域转化成有限域的人工边界研究进展问题,并对该领域今后的研究工作提出了建议。     

土—结构动力相互作用几个实际应用问题

对上－结构动力相互作用的效应和分析方法作了简要的回顾,对土－结构动力相互作用几个实际应用问题进行了分析讨论。     

考虑相邻结构影响的土-结构动力相互作用研究综述

对相邻结构动力相互作用(DCI)的研究历史与现状作了回顾和介绍,将其发展过程分为三个阶段,并对各时期发展的主要内容和特点进行了概述,最后对该领域今后的研究趋势作了分析。     

桩-土-结构动力相互作用的分析模型与方法

针对柱－土－结构动力相互作用问题中桩的分析模型、群桩效率和整个体系的分析方法等问题总结了其发展现状，讨论了今后的发展趋势，并就有待深入研究的问题提出了作者的观点。     

桩-土动力相互作用对桩基变形特性和受力性能的影响

本文研究水平地震作用下桩-土体系中桩基的地震反应,为桩基的抗震设计提供依据。以单桩为研究对象,建立有限元分析模型并加以验证,再根据场地条件选取输入波,分析了桩、桩-均匀土体、桩-分层土体3种模型处于弹性和弹塑性状态下的桩基的变形特性和受力性能。研究表明,桩动力分析时必须考虑桩周土的影响,若按静力法的桩-弹簧模型进行桩的设计会使桩身不安全。     

结构-地基相互作用体系的动力相似关系研究

模型试验的动力相似理论是结构试验技术中的一个重要的基础性研究课题。本文设计实现了缩比为1／20和1／10的结构－地基相互作用体系的振动台模型试验，通过对两个模型的试验结果的对比研究。对结构－地基相互作用体系的动力相似关系进行了初步探讨。按照本文的动力模型的设计施工及试验原则进行的模型体系的振动台试验，在结构－地基动力相互作用体系的主要特征和规律方面有较好的相似性。在激励较小阶段和激励较大阶段，两个缩尺模型在动力特性、加速度反应时程以及上部结构的应变反应等方面具有较好的相似关系；但在试验的中间阶段，两者存在明显的差异，影响两个缩尺模型在试验中间阶段的相似性的主要原因是土体在模拟地震激励下的非线性发展程度的差异。     

考虑土-结构动力相互作用效应的界限研究

开展了土-结构动力相互作用的模型试验,探讨了框架结构的近似有效基本周期,并研究了考虑相互作用效应的界限.模型试验中分别进行了刚性地基和柔性地基条件下的结构基本周期测试,并通过与理论计算结果的比较,验证了FEMA450中建议的有效基本周期计算方法能够有效预测土-结构相互作用效应的影响.利用FEMA450中建议的刚性地基上普通钢筋混凝土框架结构基本周期近似值的计算式,分别建立了明置基础、埋置基础的框架结构有效基本周期近似值的计算式,并以此分析了框架结构考虑相互作用的界限问题,提出了考虑埋置深度影响的合理界限.     

Dynamic response of cylindrical structures considering coupled soil-structure interaction under seismic loading

This paper attempts to develop a mathematical model for estimating the seismic response of a cylindrical shaped nuclear reactor building resting in an elastic halfspace considering foundation compliance. Most of the research carried out on this topic has either been carried out by resorting to finite element method (FEM) which makes the computational cost expensive or based on the simplifying assumption of assuming the cylindrical structure as a multi degree lumped mass stick model with soil coupled as boundary springs. In the present paper an analytical model has been developed in which the deformation of the cylindrical body (including its shear deformation characteristics) has been taken into cognizance and then coupling with foundation stiffness a comprehensive solution has been sought based on Galerkin’s weighted residual technique. The results are finally compared with FEM to check the reliability of the same. The results are found to be in good agreement with the detailed finite element analysis.     

Centrifugal modelling of dynamic soil-structure interaction

This paper presents a centrifuge model that is capable of realistically representing soil-structure systems subjected to earthquake-like excitation. The model is validated by performing (i) free field soil tests, (ii) dynamic soil-structure interaction tests and (iii) a numerical analysis of the experimental results. The free field experiments show that the simulated earthquake, which is generated by the hammer-exciter plate method, is similar in amplitude and frequency content to a real earthquake. The experiments also demonstrate that a confined soil sample can satisfactorily model a horizontal soil stratum of infinite lateral extent when the containment walls are lined with an absorptive material to attenuate wave reflections that would otherwise occur. Measurements of the acceleration at different locations on the free soil surface indicate that the surface motion is fairly uniform over a relatively large area. This is further confirmed by a comparison made between the measured free and scattered field motions for a surface foundation. Next, a series of soil-structure interaction tests are performed which examine the dependence of radiation damping on the natural frequencies of the structure relative to the fundamental frequency of the soil stratum. The experimental results are shown to be consistent with established theories. Finally, the experimental results are used to compute the stiffness and damping parameters of a two degree of freedom numerical model of the soil-structure system. The experimental parameters are shown to be in good agreement with calssical text book formulae. This study demonstrates that the centrifuge model consistently behaves as expected for simple, but realistic, dynamic soil and soil-structure systems, and can, therefore, be used with confidence to examine more complicated systems that are not yet fully understood.     

土与结构相互作用对储罐地震响应的影响

为了研究土与结构相互作用对储罐地震响应的影响,基于Haroun-Housner模型,将地基土考虑为平动和转动的弹簧阻尼体系,将储罐结构体系简化为三质点四自由度力学模型,来研究储罐的地震响应受地基土弹性的影响。分析结果表明:与刚性基础相比,考虑土与结构的相互作用时储罐的基底剪力、倾覆力矩和晃动波高均有放大效应,且与储液高度与半径比相关,为获得理想的地震响应储液高度与半径比存在优化取值区间。     

土-结构动力相互作用对结构控制的影响

本文研究了土-结构动力相互作用对采取不同控制措施的结构控制效果的影响。文中首先建立了主动调谐质量阻尼器(ATMD)、半主动磁流变阻尼器(MR)和被动多重调谐质量阻尼器(MTMD)等三种结构控制措施在时域中的控制算法和控制律，然后基于子结构法，采用间接边界元方法，通过傅里叶变换，推导了分别安装三种结构控制措施的受控结构在频域中的运动方程，数值仿真分析了某36层高层建筑的地震反应及其控制效果。结果表明，当采用ATMD或MTMD控制时，考虑土-结构动力相互作用后结构地震反应有所减小；当采用MR控制时，考虑土-结构动力相互作用后结构地震反应有很大程度的减小。由此看来，在设计软土地基上高层结构的结构控制措施时，不考虑土-结构动力相互作用对结构控制效果的影响是偏于安全的。     

土-结构动力相互作用对基础隔震的影响

本文研究土-结构动力相互作用对基础隔震的影响。文中根据间接边界元方法，推导了空间域中的格林函数公式，并建立了地基土的动力刚度矩阵；进而在频域内采用子结构法，建立了考虑土-结构动力相互作用的隔震结构的运动方程；通过数值仿真某具有埋置刚性基础的剪切型基础隔震结构的地震反应，分析了地基土的刚度对隔震效果以及结构地震反应的影响，得到了一些有意义的结论。     

Non-linear seismic response analysis of soil-structure interaction systems

This paper presents an effective analysis procedure for the dynamic soil-structure interaction problem considering not only the sliding and separation phenomena but also the non-linear behaviour of soil by the finite element method. Soil is assumed to be an elasto-plastic material and the contact surface between the soil and structure is modelled by the joint element. The load transfer method is adopted to carry out dynamic non-linear response analysis. The method is applied to the response analysis of a nuclear reactor building resting on the ground surface. The effects of non-linear behaviour of soil on the safety against sliding of the structure are examined. The numerical computations reveal the following results: that the non-linear behaviour of soil reduces the response of the system and the magnitude of sliding of the structure, and that the safety against sliding obtained by the proposed method is higher than the safety obtained by classical methods. This implies the possibility of a more rational and economical design of large structures; it can be said that the proposed method provides useful information for the stability analysis of important and large structures.