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北京饭店消能减振抗震加固分析与设计:时程分析法 总被引：6，自引：2，他引：6
在北京饭店抗震加固改造工程中,采用了消能减振新技术.本文考虑结构弹塑性变形、普通支撑弹塑性屈曲、消能支撑非线性刚度和非线性阻尼特性,采用Wilson-θ法编制了消能结构非线性分析程序;然后,利用此程序对消能支撑加固后的北京饭店西楼主体结构进行了时程分析的抗震计算和验算,并对消能支撑加固的结构体系进行了消能分析,全面地揭示了消能支撑加固的合理性和有效性. 相似文献
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提出了一种既有钢筋混凝土框架结构的抗震加固方法,该法采用防屈曲支撑提高框架结构体系的水平承载力和耗能能力,利用外包钢进一步提高柱子的抗弯和抗剪承载力。采用开源有限元程序OpenSees,分别建立空钢筋混凝土框架和防屈曲支撑加固钢筋混凝土框架的分析模型,对2榀钢筋混凝土框架的抗震性能进行模拟。防屈曲支撑采用了弹塑性桁架单元模型,加固框架柱混凝土考虑了外包钢的约束作用。将分析结果与拟静力试验结果进行比较,以检验分析模型的准确性,以及研究防屈曲支撑和外包钢对混凝土框架抗震性能的影响。分析结果表明,数值模拟与试验结果吻合较好,验证了基于OpenSees建立的数值模型的准确性;外包钢有效改善了框架柱的抗弯承载力和变形能力;防屈曲支撑显著提高了加固框架体系的水平刚度、水平承载力和耗能能力。 相似文献
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防压曲支撑作为一种新型耗能减震构件,能用于抑制普通支撑的压曲现象,能更多地吸收和耗散地震输入结构的能量,提高框架的抗震性能.目前,常规屈曲约束支撑的芯材和无粘结材料一般采用特殊材料制成,加工制作成本较高,不利于工程推广使用.提出 了一种点接触式防屈曲支撑(point - contact buckling - restrained braces,PBRB),由核心钢管、约束套管及之间的垫环构成,各部件均采用普通钢材,且制作工艺简单.基于ABAQUS工作平台,通过改变PBRB的相关参数,对PBRB的稳定及延性性能进行了系统研究.结果表明,所提出的PBRB具有稳定的工作性能和良好的延性;在相同条件下,PBRB的稳定和延性性能与常规屈曲约束支撑相比差别不大;PBRB屈服后承载力基本保持在核心钢管屈服段的屈服荷载Fv附近,无强化上升段,降低了对约束单元的要求. 相似文献
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设置防屈曲支撑的钢管混凝土框架是一种新型钢管混凝土减震结构。采用有限元软件Opensees对设置防屈曲支撑的单层单跨钢管混凝土减震框架进行数值模拟,研究了框架梁柱线刚度比、防屈曲支撑初始刚度以及钢管混凝土柱轴压比等设计参数对该减震结构抗震性能的影响。研究结果表明：1数值模拟和试验结果吻合较好,验证了有限元模型的正确性;2梁柱线刚度比在0.1~0.3之间变化时,钢管混凝土减震框架的抗震性能较好;3BRB耗能支撑的初始刚度K1在40~80kN/mm变化时,减震框架的耗能减震效应较明显;4在合理的钢管混凝土柱轴压比范围内,当轴压比较大时,在钢管混凝土框架中设置防屈曲支撑能明显地提高结构的耗能能力和改善结构的强度退化现象。 相似文献
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当前方法采用伸臂桁架加固建筑结构时,未考虑建筑结构的屈曲约束支撑力的影响,伸臂桁架与建筑结构的连接不牢固,导致其对建筑结构的抗震加固性能较差。故此,深入分析建筑结构的屈曲约束支撑对其抗震加固性能的影响,设计建筑结构抗震加固方案,利用高强螺栓节点经由连接钢板实现屈曲约束支撑与建筑结构的铰接固定。分别从支撑变形同建筑结构层间位移的关系、建筑结构支撑承载力、多遇地震影响下屈曲约束支撑框架的位移验算,以及罕遇地震影响下屈曲约束支撑的弹塑性位移验算方面,分析屈曲约束支撑对建筑结构抗震加固性能影响。经实验分析得出,建筑结构加入屈曲约束支撑后第一扭转周期同第一平动周期的比值降低0.14,X、Y两个方向的砌体墙同建筑结构的刚度比值降低6.9、8.0,最大顶点位移值降低15.4 mm、29.3 mm,抗震加固性能大大提高。 相似文献
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基于性能的碳纤维抗震加固设计 总被引：2，自引：1，他引：1
本文探讨了基于性能的加固设计的基本思路和设计过程,并给出了一个基于性能的碳纤维加固设计的工程实例,采用pushover静力推覆分析的方法分析对比了结构加固前后的性能,表明原结构的抗震性能不足,经碳纤维加固后的结构抗震性能明显提高,满足8度抗震设防烈度要求。 相似文献
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新版抗震设防烈度区划图实施以来,大量单跨框架结构校舍因抗侧力体系不合理以及抗震承载力不足急需加固改造。针对单跨框架结构不满足刚度及承载力要求的现状,提出并阐述了BRB减震与橡胶隔震联合加固技术原理,并对昆明某实际单跨框架结构进行了动力弹性和弹塑性有限元分析,结果表明:在多遇地震下,防屈曲支撑（BRB）未屈服,结构整体处于弹性;在设防地震作用下,部分BRB屈服耗能,结构层间位移角最大值为1/582,结构主体处于弹性阶段;在罕遇地震作用下,所有BRB屈服耗能,且其滞回曲线饱满,结构弹塑性层间位移角最大值为1/148,大部分梁端部产生塑性铰,少数柱产生塑性铰,且梁较柱先出铰,表现出良好的抗震性能。研究为单跨框架结构的加固提供一条有效的新途径。 相似文献
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我国现存着大量的未经抗震设防或按老旧规范抗震设防的砌体建筑,为了避免这些建筑在地震作用下的严重破坏,需要对其进行加固。近年来发生的汶川地震和芦山地震中,很多砌体结构损伤严重,但尚未倒塌,这些砌体结构是否可以修复,如何修复,修复后抗震性能有什么变化,目前还没有系统的研究可以借鉴。本文在基于性能的地震工程框架下,对砌体结构进行抗震加固与震后修复,并通过足尺结构试验评估其性能。本文主要工作如下:(1)对某老旧砌体结构采用后张预应力技术进行抗震加固,并对加固后砌体结构进行了双向拟静力试验。附加预应力水平采用砌体结构抗压强度设计值的20%,在提高承载力的同时避免剪压破坏。本文详细介绍了后张预应力加固二层砌体结构模型的加固流程,拟静力试验的加载和测量方案,并对砌体结构的损伤程度进行了分析和评估。(2)对采用后张预应力技术加固的砌体结构进行数值模拟。分别采用MSC.Marc和OpenSEES软件建立了加固砌体结构的精细化有限元模型和宏观力学模型。精细化有限元模型采用连续化方法和弹塑性损伤模型模拟砌体的破坏过程;而宏观力学模型采用剪切弹簧模拟墙片的宏观力学行为,通过分析50个后张预应力加固砌体墙片的试验数据,回归了加固墙片的开裂荷载计算公式。通过精细化有限元模型和宏观力学模型得到的滞回曲线与试验曲线的对比可知,这两种建模方法与试验吻合的较好,可以为该种结构的抗震性能研究提供一定的参考。(3)未加固砌体结构拟静力试验。预应力加固结构拟静力试验后结构的第二层破坏较轻,刚度损伤较小。为了对比加固效果,本文将第一层用钢梁固定,而将预应力筋值调整为结构第二层自重对第一层的压应力,对第二层结构进行加载,模拟未加固结构的首层力学性能。通过对比可知,预应力加固可使结构的峰值承载力提高至未加固结构的2倍左右,且结构的耗能能力也大幅度增加。(4)基于性能的砌体结构修复研究。对上述试验过后的损伤结构进行损伤评估后,综合考虑费用、工期和修复后承载力三方面的因素确定修复目标,根据修复目标选择增设构造柱和水泥砂浆钢筋网面层两种加固方法对损伤结构进行修复,通过修复过程中对工期和费用的量化可知,修复结构与新建结构相比可大大减少费用、缩短工期。通过修复结构的拟静力试验可知,修复结构的峰值承载力分别是未加固结构的2.84倍,预应力加固结构的1.32倍,满足修复目标的要求。 相似文献
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参数化的装配式钢混组合结构建筑信息模型缺少结构信息描述,无法实现装配式钢混组合结构图档的修正和自主更新,对结构构件的损伤评估效果差,抗震加固性能差。据此提出用于装配式钢混组合结构抗震加固的建筑信息模型,模型框架包括建筑设计模型、结构设计模型、结构抗震加固设计和损伤评估;通过结构构件的实体定义、属性定义和关联性定义,全面描述柱、梁、板和墙等钢混组合结构构件的抗震加固性能信息;采用模糊加固评估方法获取精准的结构构建综合损伤指数,评估结构构件的加固等级,提高抗震加固性能。经实验证明,所设计模型得到的结构损伤指数与实际损伤指数的误差低于0.03,说明该模型分析装配式钢混组合结构抗震加固性能准确性较高。 相似文献
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Effect of non‐moment braced frame seismic deformations on buckling‐restrained brace end connection behavior: Theoretical analysis and subassemblage tests 
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下载免费PDF全文 In‐plane buckling‐restrained brace (BRB) end rotation induced by frame action is a commonly observed phenomenon in buckling‐restrained braced frames (BRBFs). However, its effect on BRB end connection behavior has not yet been clear. In this study, four BRB end deformation modes for quick determination of end rotational demand are proposed for non‐moment BRBF considering different BRB arrangements, installing story of BRBs, and boundary condition of corner gussets connected with column base. Key factors affecting BRB end rotation and flexural moments are examined theoretically by parametric analysis. Subassemblage tests of seven BRB specimens under horizontal cyclic loading were conducted by adopting two loading frames to impose the expected BRB end deformations. It shows that BRB end rotation subjected BRB ends to significant flexural moments, leading to premature yielding of BRB ends or even tendency of end zone buckling. The deformation modes, the flexural rigidity of BRB ends, and the initial geometric imperfections of BRBs were found to have significant influence on BRB end connection behavior. The triggering moment induced by BRB end rotation was the main contributor to end flexural moment. However, the moment amplification effect induced by flexure of BRB end zones became prominent especially for small flexural rigidity of BRB ends. Implications and future research needs for design of BRB end connections are provided finally based on the theoretical and experimental results. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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A welded end‐slot buckling‐restrained brace (WES‐BRB) has been developed at the Taiwan National Center for Research on Earthquake Engineering (NCREE). A steel frame equipped with a WES‐BRB can offer a cost‐effective solution to meet interstory drift and earthquake‐resistant design requirements for seismic steel buildings. According to the WES‐BRB and connection design procedure proposed by NCREE, there are seven key elements of a buckling‐restrained braced frame (BRBF) design that require design checking. In order to assist an engineer with the design of the WES‐BRB members and connections, an innovative cloud service named Brace on Demand has been constructed at NCREE. In this study, using 581 BRBF design examples, the effectiveness of the proposed design procedures to meet all design checks is demonstrated. It is found that the most critical limit states for an initial design are joint region buckling, gusset plate buckling, and gusset‐to‐beam and gusset‐to‐column interface strength. Accordingly, the causes of improper designs and associated strategies for improving the initial designs are discussed in this paper. Recommendations on initial selections including the BRB joint size and gusset plate thickness are given. The paper provides the detailed road map for engineers to develop the spreadsheet for BRB and connection designs. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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以设置防屈曲支撑(Buckling-Restrained Braces,BRB)的双柱式桥墩体系为研究对象,系统分析上部结构惯性力在该体系中的传递机理;以某3×30m公路高架桥为工程背景,采用非线性时程反应分析法研究BRB的设置方式及参数取值对桥梁地震反应的影响规律,揭示BRB在双柱式桥墩中的工作机理。其研究结论为:(1)对于设置BRB的双柱式桥墩,当BRB未屈服时,通过其轴向刚度改变结构体系的传力路径,墩底弯矩、剪力降低,但墩底轴力改变量将增大,即以较大的墩身轴力改变量换取较小的墩底弯矩及剪力。(2)在BRB屈服的情况下,BRB通过改变下部结构的传力路径及滞回耗能双重机制影响结构的地震反应,BRB耗能作用将降低墩身的轴力改变量,使减震效果更优。(3)双柱式桥墩横桥向设置BRB是一种较为有效的减震体系,但其减震效果与BRB具体布置方式及力学参数取值有关。 相似文献
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Seismic performance evaluation of single damped‐outrigger system incorporating buckling‐restrained braces 下载免费PDF全文
下载免费PDF全文 The outrigger system is an effective means of controlling the seismic response of core‐tube type tall buildings by mobilizing the axial stiffness of the perimeter columns. This study investigates the damped‐outrigger, incorporating the buckling‐restrained brace (BRB) as energy dissipation device (BRB‐outrigger system). The building's seismic responses are expected to be effectively reduced because of the high BRB elastic stiffness during minor earthquakes and through the stable energy dissipation mechanism of the BRB during large earthquakes. The seismic behavior of the BRB‐outrigger system was investigated by performing a spectral analysis considering the equivalent damping to incorporate the effects of BRB inelastic deformation. Nonlinear response history analyses were performed to verify the spectral analysis results. The analytical models with building heights of 64, 128, and 256 m were utilized to investigate the optimal outrigger elevation and the relationships between the outrigger truss flexural stiffness, BRB axial stiffness, and perimeter column axial stiffness to achieve the minimum roof drift and acceleration responses. The method of determining the BRB yield deformation and its effect on overall seismic performance were also investigated. The study concludes with a design recommendation for the single BRB‐outrigger system. 相似文献
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Experimental study of deformable connection consisting of buckling‐restrained brace and rubber bearings to connect floor system to lateral force resisting system 下载免费PDF全文
下载免费PDF全文 Georgios Tsampras Richard Sause Robert B. Fleischman Jose I. Restrepo 《地震工程与结构动力学》2017,46(8):1287-1305
This paper presents experimental and numerical studies of a full‐scale deformable connection used to connect the floor system of the flexible gravity load resisting system to the stiff lateral force resisting system (LFRS) of an earthquake‐resistant building. The purpose of the deformable connection is to limit the earthquake‐induced horizontal inertia force transferred from the floor system to the LFRS and, thereby, to reduce the horizontal floor accelerations and the forces in the LFRS. The deformable connection that was studied consists of a buckling‐restrained brace (BRB) and steel‐reinforced laminated low‐damping rubber bearings (RB). The test results show that the force–deformation responses of the connection are stable, and the dynamic force responses are larger than the quasi‐static force responses. The BRB+RB force–deformation response depends mainly on the BRB response. A detailed discussion of the BRB experimental force–deformation response is presented. The experimental results show that the maximum plastic deformation range controls the isotropic hardening of the BRB. The hardened BRB force–deformation responses are used to calculate the overstrength adjustment factors. Details and limitations of a validated, accurate model for the connection force–deformation response are presented. Numerical simulation results for a 12‐story reinforced concrete wall building with deformable connections show the effects of including the RB in the deformable connection and the effect of modeling the BRB isotropic hardening on the building seismic response. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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设计制作了一种新型全钢、装配式的防屈曲耗能支撑(BRB),给出了主要的理论计算公式,采用有限元方法对其工作过程和机理进行数值模拟并进行了足尺实验研究,最后,将这种装置安装到框架结构,基于非线性动力时程分析评估其减震性能.研究结果表明了简化计算和有限元分析在产品初步设计中的有效性;防屈曲耗能支撑明显减小了结构动力响应,提... 相似文献
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A thin‐profile buckling‐restrained brace (thin‐BRB) consists of a rectangular steel casing and a flat steel core that is parallel to a gusset plate. A thin configuration reduces the width of the restraining member and thus saves usable space in buildings. However, deformable debonding layers, which cover the steel core plate in order to mitigate the difference between the peak tensile and compressive axial forces, provide a space for the steel core to form high mode buckling waves when the thin‐BRB is under compression. The wave crests squeeze the debonding layers and produce outward forces on the inner surface of the restraining member. If the restraining member is too weak in sustaining the outward forces, local bulging failure occurs and the thin‐BRB loses its compression capacity immediately. In order to investigate local bulging behavior, a total of 22 thin‐BRB specimens with a ratio of steel core plate to restraining steel tube depth ranging from 0.3 to 0.7 and axial yield force capacities ranging from 421 kN to 3036 kN were tested by applying either cyclically increasing, decreasing, or constant axial strains. The restraining steel tube widths of all the specimens were smaller than 200 mm and were infilled with mortar with a compressive strength of 97 MPa or 55 MPa. Thirteen of the 22 thin‐BRB specimens' restraining members bulged out when the compressive core strains exceeded 0.03. A seismic design method of the thin‐BRB in preventing local bulging failure is proposed in this study. Test and finite element model (FEM) analysis results suggest that the outward forces can be estimated according to the BRB compressive strength, steel core high mode buckling wavelength, and the debonding layer thickness. In addition, the capacity of the restraining member in resisting the outward forces can be estimated by using the upper bound theory in plastic analysis. Both the FEM analysis and test results indicate that the proposed method is effective in predicting the possibility of local bulging failure. Test results indicate that the proposed design method is conservative for thin‐BRB specimens with a large steel core plate to restraining steel tube depth ratio. This paper concludes with design recommendations for thin‐BRBs for severe seismic services. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Buckling-restrained braces(BRBs)have recently become popular in the United States for use as primary members of seismic lateral-force-resisting systems.A BRB is a steel brace that does not buckle in compression but instead yields in both tension and compression.Although design guidelines for BRB applications have been developed,systematic procedures for assessing performance and quantifying reliability are still needed.This paper presents an analytical framework for assessing buckling-restrained braced f... 相似文献