某框架结构基础隔震地震反应对比分析

基于结构动力学原理和有限元基本理论,利用SAP2000有限元分析软件,以某框架结构基础隔震楼和与其相近的非隔震楼为研究对象分别建立分析模型,运用动力时程分析法对两种模型进行水平地震反应分析。结果表明:基础隔震楼的水平向地震反应远小于非隔震楼,其上部结构的自振周期明显大于非隔震楼,其层间剪力和基底剪力、楼层相对位移和加速度低于非隔震楼。总体来说,隔震支座可以显著降低水平向地震对于结构的不良反应,值得推广应用。     

基于线性流变模型的基础隔震系统的动力特性研究

为了更准确地分析基础隔震系统的动态响应和隔离能力,构建服从Hooke定律、Kelvin/Voigt定律的线性流变模型,采用1977年罗马尼亚地震的数据资料,对该模型进行动力特性的理论分析和实验研究,然后建立相关参数的表达式,发现各参数受到黏性阻尼系数c的离散变化和角速度ω的连续变化影响较大。通过与实验对比发现所建立表达式是正确的。可以通过最大传递力Q0和运动传递率T来评估系统的动态隔离能力。     

基础隔震设计的简化计算

提出采用工程软件实现基础隔震计算分析的多种简化方法,主要包括计算模型的建立和地震作用效应的计算。对不同方法的适用条件和计算结果差异进行讨论,并通过算例加以说明,可供设计人员进行基础隔震设计时参考。     

基于磁流变阻尼器与弹性基础隔震耦合建筑的地震响应分析

为了减少地震时相邻建筑间相互撞击造成严重的结构损坏,运用Lyapunov法作为控制算法进行稳定性分析和控制器设计,对半主动控制以及两种混合控制方案性能进行了对比分析,经过研究发现,混合控制策略在缓解地震响应方面比半主动控制更有效。选取适当的混合控制能够减少支座位移,从而有效防止冲击。另外,通过参数学习发现增加隔震阻尼和强度会导致基础剪力增加和支座位移减小,选择适当的参数值,能够保证响应限定在一定范围内。     

Response of a double‐wedge base‐isolation device

A novel base‐isolation device is described and its performance is compared with that of a friction pendulum bearing. In its simplest form, the device consists of two wedges sliding on a horizontal plane in opposite directions and constrained from retreating by ratchets or bilinear dampers. The superstructure rests at the intersection of the two wedges. For a sufficiently large horizontal acceleration of the base, the structure starts to move up the inclined plane of one of the wedges, which remains fixed while the second wedge is slaved to follow the structure. As the direction of the base acceleration reverses, the process is reversed and the structure starts to climb on the second inclined plane while the first wedge follows. The overall result is that the horizontal acceleration of the structure is reduced with respect to that of the base and that kinetic energy associated with horizontal velocities is systematically transformed into potential energy. In the case of motion in a vertical plane, the device has the following advantages over a friction pendulum: (i) the sliding surface is linear instead of curved, (ii) kinetic energy is systematically transformed into potential energy during the strong ground motion, and (iii) the device is slowly self‐centering. Copyright © 2004 John Wiley & Sons, Ltd.     

柱顶层间隔震体系增量动力响应研究

针对悬臂柱顶有拉梁和无拉梁层间隔震体系的抗震性能问题,运用增量动力分析(IDA)方法进行弹塑性分析,模拟结构从弹性到弹塑性直至最后倒塌的全过程。通过调幅地震动得到相应的层间位移角及峰值加速度,分别绘制单条与多条IDA曲线分析拉梁对隔震结构动力响应的影响,研究两种结构的抗震性能。结果表明:在相同性能点,有拉梁和无拉梁对纤维铰弯矩值和曲率值基本无影响,而在不同性能点,纤维铰状态明显不同;两种体系从正常使用阶段到防止倒塌阶段所需的加速度峰值的差距慢慢增大;在极罕遇地震下,柱顶有拉梁层间隔震体系的下部结构抗震性能要高于柱顶无拉梁层间隔震体系。     

连续梁桥减震、隔震体系非线性地震反应分析

本文采用微分型滞回恢复力模式代表桥梁减震,隔震支座的滞回,耗能特性,结合Ｗｉｌｓｏｎ－θ法和四阶Ｒｕｎｇｅ－Ｋｕｔｔａ法编制了桥梁减震,隔震体系非线性地震反应分析程序,并利用程序结合算例分析了减震,隔震支座对连续梁桥的减震效果。     

设置限位器双向隔震铁路桥梁车桥耦合动力响应研究

对铅芯橡胶双向隔震铁路桥梁在列车荷载作用下的力学性能进行了研究,针对双向隔震铁路桥梁中存在的问题,提出了设置限位器的解决方案,并对设置限位器的双向隔震铁路桥梁进行了车桥耦合动力响应分析。研究结果表明,采用常规隔震设计方法的铅芯橡胶支座在横桥向的初始刚度和屈服强度均不能满足规范要求,设置限位器后,双向隔震铁路桥梁的力学性能有了很大的改善,各项指标均满足列车运行安全性和平稳性要求。     

Base isolation for retrofitting historic buildings: Evaluation of seismic performance through experimental investigation

An experimental test program on a full‐scale model representing a sub‐assemblage of the cloister facade of the Sao Vicente de Fora monastery, retrofitted through base isolation, has been recently carried out at the European Laboratory for Structural Assessment of the Joint Research Centre of the European Commission. In this paper an overview of the laboratory model and the experimental results is provided. In particular, firstly the test model is described, including the geometry and mechanical properties of the masonry specimen and the design of the isolation devices; then the testing method and the sub‐structuring of the isolation system are described and the seismic inputs adopted for the pseudo‐dynamic tests are defined. Finally, the experimental results are discussed and compared to the analogous results obtained on the ‘as is’, fixed‐base sub‐assemblage model. The implications of the test outcomes are emphasized and developments of this research line are presented. Copyright © 2001 John Wiley & Sons, Ltd.     

地冲击荷载作用下双层结构磁流变阻尼器隔震效果的数值模拟

在抗爆结构中,一般采用单层隔震系统进行隔震,目前单层隔震系统的最大隔震率可以达到90％以上,但在加速度峰值很高的冲击荷载作用下,隔震后的结构响应加速度仍然很大。鉴于这种情况,本文对加入磁流变阻尼器（MRD）的双层隔震系统进行了研究。针对抗爆结构的两种典型荷载,采用改进Bouc—Wen模型和模糊控制方法,利用Matlab Simulink对双层隔震系统进行了数值模拟,计算了不同荷载作用下,不同隔震系统的加速度、位移及结构的振动剂量值（VDV）的响应,并与结构采用单层隔震系统的结果进行了对比。结果表明,与单层隔震系统相比,带有磁流变阻尼器的双层隔震系统没有太多的优越性。     

建筑结构基础隔震技术的研究和应用

本文介绍了建筑结构基础隔震基本原理、隔震系统分类、隔震技术进展、隔震设计一般流程、隔震相关专著、隔震规范和应用软件,并提出隔震技术推广中有待解决的几个问题。     

Damage detection of base‐isolated buildings using multi‐input multi‐output subspace identification

A damage detection algorithm of structural health monitoring systems for base‐isolated buildings is proposed. The algorithm consists of the multiple‐input multiple‐output subspace identification method and the complex modal analysis. The algorithm is applicable to linear and non‐linear systems. The story stiffness and damping as damage indices of a shear structure are identified by the algorithm. The algorithm is further tuned for base‐isolated buildings considering their unique dynamic characteristics by simplifying the systems to single‐degree‐of‐freedom systems. The isolation layer and the superstructure of a base‐isolated building are treated as separate substructures as they are distinctly different in their dynamic properties. The effectiveness of the algorithm is evaluated through the numerical analysis and experiment. Finally, the algorithm is applied to the existing 7‐story base‐isolated building that is equipped with an Internet‐based monitoring system. Copyright © 2004 John Wiley & Sons, Ltd.     

Time domain identification of hybrid base isolation systems using free vibration tests

A procedure for the dynamic identification of the physical parameters of coupled base isolation systems is developed in the time domain. The isolation systems considered include high damping rubber bearings (HDRB) and low friction sliding bearings (LFSB). A bi‐linear hysteretic model is used alone or in parallel with a viscous damper to describe the behavior of the HDRB system, while a constant Coulomb friction device is used to model the LFSB system. After deriving the analytical dynamical solution for the coupled system under an imposed initial displacement, this is used in combination with the least‐squares method and an iterative procedure to identify the physical parameters of a given base isolation system belonging to the class described by the models considered. Performance and limitations of the proposed procedure are highlighted by numerical applications. The procedure is then applied to a real base isolation system using data from static and dynamic tests performed on a building at Solarino. The results of the proposed identification procedure have been compared to available laboratory data and the agreement is within ±10%. However, the need for improvement both in models and testing procedures also emerges from the numerical applications and results obtained. Copyright © 2010 John Wiley & Sons, Ltd.     

Experimental evaluation of piecewise exact solution for predicting seismic responses of spherical sliding type isolated structures

The use of base isolation for enhancing seismic resistibility has been proven as an efficient method in experimental and theoretical studies. It is usual to insert a flexible device in the horizontal direction to permit the most of relative deformation of a structure at this level. Because the rigidity of the superstructure is much higher than that of the base isolator underneath the structure, the behavior of the superstructure can be idealized as a rigid body during earthquakes. In general, hundreds of degrees of freedom and a step‐by‐step time history analysis are the basic requirements for calculating the seismic response of a base‐isolated structure under earthquakes. In order to develop a simple tool which can be easily adopted for calculating the seismic responses of the spherical sliding type isolated structures, a piecewise exact solution for predicting the seismic responses of base‐isolated structures has been derived in this study. The comparison between the experimental results conducted at the National Center for Research on Earthquake Engineering (NCREE) in Taiwan and the analytical results obtained from the piecewise exact solution show that the formulation derived in this study can predict the seismic responses of the base‐isolated structure with a very high accuracy. Copyright © 2005 John Wiley & Sons, Ltd.     

近断层地震作用下基础隔震层组合限位振动台实验研究

近断层脉冲型地震作用下,基础隔震结构隔震层会产生过大变形,导致隔震支座侧倾失稳,隔震体系破坏。设计制作了3层基础隔震钢框架实验模型和11种U型钢板I型铅棒组合限位器,进行了U型钢板静力加载实验和近断层脉冲型地震作用下基础隔震层软碰撞限位振动台模型实验。实验表明：①静力加载时,U型钢板具有很好的弹性性能;②动力作用下,组合限位器残余变形较小,仍具有良好限位复位能力;③近断层地震作用下,基础隔震层软限位效果良好,同时控制上部结构层间变形在允许范围内。     

高层隔震结构非线性地震响应分析及设计方法研究

高层隔震结构的分析理论和设计方法是目前隔震技术向高层建筑推广的2个关键理论问题。本文以高烈度区宿迁市已经竣工的高层隔震建筑阳光大厦为工程实例,对高层隔震结构的非线性地震响应分析方法进行了研究,包括隔震支座竖向不同拉压刚度的模拟、各种类型的隔震支座水平力学特性的准确模拟,以及不同地震动输入方式和输入角度对隔震支座受拉情况的影响分析等;在此基础上,对隔震层的设计方法进行了分析,提出了隔震层设计的基本原则,进而给出了控制隔震层设计的基本指标,包括隔震支座的长期面压、极值面压、隔震层偏心率等;最后,对高层隔震结构的相关构造要求进行了必要的说明。     

Dynamic testing and system identification of a multi-span highway bridge

A simple and effective procedure for conducting the free vibration test on highway bridges is presented. The impulsive force in each direction is generated by a loaded truck that either stops suddenly or falls down from a rigid block. The feasibility of the procedure is demonstrated in identification of the dynamic properties, i.e. the vibration frequencies, mode shapes, and damping ratios, of a three-span box-girder concrete bridge using the Ibrahim Time-Domain (ITD) technique. Up to 14 modes have been identified for the present case. For the purpose of verification, ambient vibration tests were also carried out, with the data processed by the random decrement (Randomdec) technique to yield the free vibration response, followed by the ITD technique. The dynamic properties identified from the two types of test correlate very well with each other, indicating the validity of each procedure described herein. Although many more modes can be identified from the free vibration test because of the higher quality of data produced, the easiness and general applicability of the ambient vibration test can still be appreciated. A comparison of the experimental results with those by the finite element method indicated a lesser degree of correlation, implying that the finite element model adopted in design requires further refinement, say, through a more realistic evaluation of the boundary conditions, geometric and material properties of the bridge. Copyright © 1999 John Wiley & Sons Ltd.     

Application of subspace identification technique to long‐term seismic response monitoring of structures

This paper addresses the issue of structural system identification using earthquake‐induced structural response. The proposed methodology is based on the subspace identification algorithm to perform identification of structural dynamic characteristics using input–output seismic response data. Incorporated with subspace identification algorithm, a scheme to remove spurious modes is also used to identify real system poles. The efficiency of the proposed method is shown by the analysis of all measurement data from all measurement directly. The recorded seismic response data of three structures (one 7‐story RC building, one midisolation building, and one isolated bridge), under Taiwan Strong Motion Instrumentation Program, are analyzed during the past 15 years. The results present the variation of the identified fundamental modal frequencies and damping ratios from all the recorded seismic events that these three structures had encountered during their service life. Seismic assessment of the structures from the identified system dynamic characteristics during the period of their service is discussed. Copyright © 2014 John Wiley & Sons, Ltd.     

摩擦-钢管混凝土短柱复合隔震支座性能试验与隔震分析

作者在钢管混凝土柱支座隔震房屋实验研究中发现,隔震支座中上盖与底座的接触无论如何处理,摩擦力总是存在的．因此,隔震支座实际上是摩擦耗能与钢管混凝土耗能复合减震系统。本文通过对单个和一组隔震支座的实验研究,确定了短柱支座的恢复力模型,采用了高阶单步算法分析了装有此类支座隔震结构的地震反应,验证了复合隔震支座良好的隔震性能及隔震效果。     

滚动FPS和MR阻尼器混合基础动力学模型及仿真

本文中作者将新型双磙子FPS系统的动力学方程推广到由滚动FPS和MR阻尼器组成的混合隔震基础系统,得到了更便于应用的水平分量形式的运动微分方程,并将与FPS有关的力和MR阻尼力处理成力源项,构造了可以方便地考虑不同上部结构形式的MATLAB/SIMULINK仿真模型。采用RD-1005型MR阻尼器和模糊逻辑控制器,在两个典型的地震输入情况下对混合系统进行了振动控制仿真。仿真结果表明,本文建立的混合隔震基础系统的动力学模型是正确和精确的,直接利用动力学模型进行前向计算可避免附加的模型误差且计算效率高,而仿真模型中将不同的力源由分开的块组成,使得仿真设计非常方便快捷。