建筑隔震体系与机构的设计分析方法及工程应用

基础隔震技术可以大大提高中低层建筑及其内部设备的抗震安全可靠度 ,具有非常大的经济效益和社会效益 ,已成为工程结构抗震研究的发展方向之一 ,各国学者都在积极致力于该项技术的研究开发和推广应用。目前 ,研究得较为深入和成熟的基础隔震技术是叠层橡胶支座基础隔震技术和滑动摩擦基础隔震技术 ,而前者的研究开发和推广应用的前景更好。本文首先给出可作为隔震支座辅助机构的花瓣状螺旋弹簧刚度公式的精确解 ,证明了水平刚度具有无方向性 ,与有关文献中利用组合型圆环刚度公式作为近似的计算结果相比 ,与试验结果的符合程度更好。这些公…     

不同支座布置下组合基础隔震结构能量反应分析

通过对5种不同支座布置方案的组合基础隔震结构施加不同场地条件下的双向水平地震波,研究了场地类别和地震波加速度峰值及支座布置方式对结构总输入能量的影响,并进行了耗能分析。结果表明,随着地震波峰值的增大,结构总输入能量增大;相同地震峰值条件下,场地土越软,总的输入能量越大;组合隔震结构应用于软土场地时隔震层滞回耗能比更大,隔震效果更好;组合隔震结构两种支座中选择分散布置方案时,隔震层耗能比更大,隔震效果优于支座集中布置方案。     

叠层橡胶垫基础隔震建筑结构设计方法与应用

简要概括了国内外叠层橡胶垫基础隔震技术的应用发展状况,介绍了隔震结构的各种反应分析模型,对隔震结构设计分析方法进行了讨论,提出了有益的建议,并指出了在《建筑抗震设计规范》（GB50011-2001）关于隔震结构的简化计算方法中存在的诸多不足。结合我国的隔震技术应用现状,引入了两阶段设计法的概念。此方法将有利于提高设计质量,减少设计周期。     

宿迁市文体馆基础隔震非线性时程分析研究

宿迁市文体馆4500座位，约13000m^2,位于8度抗震设防区，主体结构为钢筋混凝土结构空间框架，钢网壳屋盖。该工程采用基础隔震技术设计，在桩基顶面与上部结构之间设置架空层，用作安置设备管道及隔震层。隔震层由叠层橡胶隔震支座和粘滞阻尼器组成。对主体结构基础隔震采用空间模型非线性时程分析方法进行了详细分析，结果表明：采用基础隔震措施可显著降低结构地震作用，上部结构水平地震作用减震系数可按0．25采用；设置附加粘滞阻尼器能较好地解决降低地震作用和限制隔震层位移之间的矛盾，对提高隔震体系的性能具有重要作用。技术经济比较表明，本工程采用基础隔震措施，具有明显的社会、经济效益。     

变刚度隔震保护装置试验研究

通过在距离隔震层一定位移处设置由弹簧和与其串联的限位挡板组成的变刚度保护装置作为第二道防线,成功地进行了五层框架的变刚度隔震保护模拟地震振动台试验。理论分析和试验结果表明,变刚度隔震保护装置能有效改变结构动力特性,减小隔震层的变形,使之限制在允许的范围内。     

建筑物隔震技术在日本的研究发展和工程应用

对日本近期开发研制的多段式隔震系统，高强度叠层像胶支座，全向滑轨隔震装置，偏心滚轴隔震装置和3维隔系系统进行了介绍。概述了日本隔震技术的工程应用情况，并对日本隔震技术的发展趋势进行了分析。     

应用基础隔震技术的建筑工程造价分析

应用叠层橡胶支座进行基础隔震是目前国内外大力推广的一门建筑抗震新技术。但由于对采用隔震技术后建筑物的工程造价是否会增加缺乏具体的经济技术指标,使得建筑开发商对其推广应用一直持保守态度。选择了位于VIII度区的两个典型工程实例(一例为乙类建筑,另一例为丙类建筑),简要分析了同一建筑物采取不同设计方案(不隔震但抗震设防、隔震使实际设防水平提高、隔震后与未隔震建筑保持相同设防水平等三种不同设计方案)对工程造价的影响及差异。分析数据表明,在同等设防烈度下,基础隔震技术的合理应用可以使被隔震建筑的工程造价与同条件只采用抗震设防的建筑工程造价适当降低。     

滑移摩擦隔震系统在多向地面运动作用下的试验研究

基础隔震通常只考虑隔离水平地面运动，而对竖向地面运动的影响注意不够，本文进行了滑移摩擦隔震系统的振动台房屋模型试验，研究多向地面运动输入时上部结构反应和隔震系统的性能，试验中分别对模型输入了不同方向的地震动，其中包括水平单向、水平双向、水平和竖向及三向地震动输入，对试验结果进行了分析比较，结果表明竖向地震动输入对上部结构的水平地震反应有显著影响，同时在橡胶隔震支座中产生了竖向拉力。     

隔震技术在高烈度区剪力墙结构中的应用研究

对于近断层处高烈度区高层剪力墙结构，传统设计难以解决墙体太厚、配筋太大等难题。为研究在考虑近断层影响下高烈度区剪力墙住宅采用隔震设计的技术可行性，采用隔震设计对某剪力墙结构工程进行全面分析。对比分析常规剪力墙结构方案及增设橡胶隔震支座的隔震方案，分析结果表明，隔震方案较常规方案前3阶结构自振周期延长约3倍，从而有效减小了上部结构的地震作用；在设防烈度地震作用下，结构水平向减震系数为0.281，上部结构所受水平地震作用和抗震措施可按降低一度进行设计；罕遇地震作用下隔震支座性能稳定，上部结构基本处于弹性工作状态。研究结论可为隔震支座设计和进一步研究提供参考。     

铅芯叠层橡胶支座基础隔震结构双向地震反应分析

本文对铅芯叠层橡胶支座双向耦合恢复力模型进行了改进，采用基础隔震结构动力分析程序DABIS对铅芯叠层橡胶支座基础隔震结构进行了单向及双向地震反应对比分析。结果表明，在单向和双向地震作用下，基础隔震结构的加速度反应和位移反应较为接近，但在双向地震作用下，支座的最大位移明显大于单向地震作用时的支座最大位移，因而在确定支座最大位移时应考虑双向地震作用的影响。     

一座空旷砖混厂房结构的隔震加固

介绍一栋砖混单层厂房的隔震加固方案，对加固后结构与原结构的地震反应作了对比分析，分析结果表明隔震加固大大提高了原结构的抗震性能。对加固所用的隔震支座性能作了具体分析，提供了支座的设计与试验对比结果，并对砌体结构隔震加固中采用的“夹梁托墙”技术的可行性作了试验研究，结果表明：支座的设计分析结果与试验结果吻合较好，夹梁具有良好的工作性能。     

Shake table tests on a mass eccentric model with base isolation

A mass eccentric structure is usually more seismically vulnerable than its concentric counterpart because of the coupled torsional–translational response of such structures. In this work, dynamic characteristics and response of a five‐storey benchmark model with moderate mass eccentricity were investigated using a shake table, simulating four different ground motions. The effectiveness of laminated rubber bearings (LRB) and lead‐core rubber bearings (LCRB) in protecting eccentric structures was examined and evaluated in relation to translational and torsional responses of the benchmark model. It was observed that both translational and torsional responses were significantly reduced with the addition of either a LRB or LCRB isolated system regardless of the nature of ground motion input. The LRB were identified to be more effective than LCRB in reducing model relative displacements, the relative torsional angle as well as accelerations, and therefore provided a better protection of the superstructure and its contents. On the other hand, LCRB rendered a smaller torsional angle and absolute displacement of the base isolation system, hence a more stable structural system. Copyright © 2003 John Wiley & Sons, Ltd.     

Seismic isolation of buildings with sliding concave foundation (SCF)

In this paper, a new base isolation system, namely the sliding concave foundation (SCF), is introduced and the behaviour of the buildings using such a system is theoretically investigated. A building supported on the new system behaves like a compound pendulum during seismic excitation. The pendulum behaviour accompanied by the large radius of foundation curvature shifts the fundamental period of the system to a high value (e.g. more than 8sec), in a frequency range where none of the previously recorded earthquakes had considerable energy. This results in a large decrease in the structural responses. Since small friction forces are essential on the contact surfaces, PTFE sheets can be used as sliding surfaces. Although the pure frictional sliding systems have the same efficiency as the SCF, in reducing the responses of the superstructure, the main advantage of the new system is a significant decrease in sliding displacement. The performance of the SCF subjected to a number of harmonic and non‐harmonic base excitations is studied and its ability to reduce the structural responses is examined. Some numerical examples are solved for a single‐degree‐of‐freedom (SDOF) structure and the responses are compared with the responses of the same SDOF structure on a fixed base or a pure frictional sliding support system. The comparisons confirm the effectiveness of the new system. Copyright © 2002 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.     

Efficiency of base isolation systems in structural seismic protection and energetic assessment

This paper concerns the seismic response of structures isolated at the base by means of High Damping Rubber Bearings (HDRB). The analysis is performed by using a stochastic approach, and a Gaussian zero mean filtered non‐stationary stochastic process is used in order to model the seismic acceleration acting at the base of the structure. More precisely, the generalized Kanai–Tajimi model is adopted to describe the non‐stationary amplitude and frequency characteristics of the seismic motion. The hysteretic differential Bouc–Wen model (BWM) is adopted in order to take into account the non‐linear constitutive behaviour both of the base isolation device and of the structure. Moreover, the stochastic linearization method in the time domain is adopted to estimate the statistical moments of the non‐linear system response in the state space. The non‐linear differential equation of the response covariance matrix is then solved by using an iterative procedure which updates the coefficients of the equivalent linear system at each step and searches for the solution of the response covariance matrix equation. After the system response variance is estimated, a sensitivity analysis is carried out. The final aim of the research is to assess the real capacity of base isolation devices in order to protect the structures from seismic actions, by avoiding a non‐linear response, with associated large plastic displacements and, therefore, by limiting related damage phenomena in structural and non‐structural elements. In order to attain this objective the stochastic response of a non‐linear n‐dof shear‐type base‐isolated building is analysed; the constitutive law both of the structure and of the base devices is described, as previously reported, by adopting the BWM and by using appropriate parameters for this model, able to suitably characterize an ordinary building and the base isolators considered in the study. The protection level offered to the structure by the base isolators is then assessed by evaluating the reduction both of the displacement response and the hysteretic dissipated energy. Copyright © 2003 John Wiley & Sons, Ltd.     

Comparative study of the inelastic response of base isolated buildings

This article presents a numeric comparative study of the inelastic structural response of base isolated buildings. The comparative study includes the following isolation systems: laminated rubber bearings, New Zealand one, pure friction and the frictional pendulum ones. The study is based on obtaining non‐linear response spectra for various design parameters using six earthquake records. Usually the base isolation of a new building seeks to maintain the structure in the linear elastic range. The response of old weak buildings or the response of new ones subjected to extreme earthquakes may not be, necessarily, in the aforementioned ideal elastic range. Consequently, it is important to characterize the response of isolated buildings responding inelastically. A conclusion from this research is that the isolators affect significantly the structural response of weak systems. Rubber isolators seem slightly less sensitive to plastification that may occur in the structure compared to friction isolators. Ductility demands in the structure are affected significantly by friction and neoprene protected systems, in particular sliding ones where larger demands are obtained. Copyright © 2002 John Wiley & Sons, Ltd.     

基础滑移隔震结构振动特性分析

通过对基础滑移隔震体系等代模型自振特性的分析，就多自由度剪切型隔震结构振动特性进行了较为全面的探讨，从而为滑移隔震结构的动力计算建立了合理的理论依据。     

A base isolation system for bridges subjected to seismic disturbances

The study reported in this paper investigates the feasibility of developing an active base isolation system for the protection of bridges subjected to earthquakes. The proposed system incorporates spherical supports, cams and springs which can be optimally designed to minimize the transmissibility of the seismic disturbances to the bridge. The considered example shows that the proposed design is implementable and can provide an order of magnitude reduction in the maximum stress resulting from seismic waves acting on the bridge in the transverse or longitudinal direction. Since the system performance is highly dependent on the rapid unlocking of the cams in the event of a seismic disturbance, careful consideration should be given to the design of a reliable cam release control. This can be achieved by spring loading each cam such that it would be normally unlocked. A hydraulic actuator would be used to force it to rotate to the locking position under fluid pressure which would be constantly maintained at the design level during normal conditions. The actuator would be equipped with a quick response release valve for rapidly releasing the pressure and consequently unlocking the cam as soon as an earthquake is detected. Copyright © 2002 John Wiley & Sons, Ltd.     

Sliding mode control of buildings with base‐isolation hybrid protective system

This paper investigates the application of the sliding mode control (SMC) strategies for reducing the dynamic responses of the building structures with base‐isolation hybrid protective system. It focuses on the use of reaching law method, a most attractive controller design approach of the SMC theory, for the development of control algorithms. By using the constant plus proportional rate reaching law and the power rate reaching law, two kinds of hybrid control methods are presented. The compound equation of motion of the base‐isolation hybrid building structures, which is suitable for numerical analysis, has been constructed. The simulation results are obtained for an eight‐storey shear building equipped with base‐isolation hybrid protective system under seismic excitations. It is observed that both the constant plus proportional rate reaching law and the power rate reaching law hybrid control method presented in this paper are quite effective. Copyright © 2000 John Wiley & Sons, Ltd.     

Response of structures supported on SCF isolation systems

Aseismic base isolation is an effective method used to protect structures and their contents against earthquakes. An isolated structure may be designed to remain elastic throughout major ground motions as a result of the efficiency of the isolation systems. In this paper, the equations of motion of two‐dimensional elastic structures supported on a new base isolation system called the Sliding Concave Foundation (SCF) are presented and a procedure for their solution is suggested. The responses of a number of structures subjected to different earthquake records are evaluated and the results are compared with those of the same structures supported on two other famous isolation systems and also a fixed base condition. The results indicate the effectiveness of the SCF in protecting the supported structures even during very strong and/or long period earthquakes. Copyright © 2003 John Wiley & Sons, Ltd.