Seismic performance of steel coupling beam-wall connections in panel shear failure

Increasingly, engineers are designing hybrid and mixed building systems of structural steel and reinforced concrete to produce more efficient structures than can be realized using either material alone. Recent literature has pointed out a need for greater understanding of the interaction of structural steel and reinforced concrete in such systems. In this paper, the seismic performance of steel coupling beam-wall connections in a hybrid coupled shear wall system is examined through results of an experimental research programme where three 2/3-scale specimens were tested under cyclic loading. The test variables included the reinforcement details that confer a ductile behaviour on the steel coupling beam-wall connections, i.e., the face bearing plates and the horizontal ties in the panel region of the steel coupling beam-wall connections. It investigates the seismic behaviour of the steel coupling beam-wall connections in terms of the failure mechanism, hysteretic response, strength, stiffness, and dissipated energy characteristics. The results and discussion presented in this paper provide background for a companion paper that includes a design model for calculating the panel shear strength of the steel coupling beam-wall connections.     

Seismic behaviour of coupling beams in a hybrid coupled shear walls

Steel coupling beams in a hybrid coupled shear wall provide a viable alternative for concrete coupling beams coupling individual reinforced concrete wall piers. Due to the lack of information, current design methods for calculating embedment lengths are silent about cases in which hybrid coupled walls have connection details of stud bolts and horizontal ties. In this work, an analytical study was carried out to develop a model for calculating the embedment lengths of embedded steel sections. Five models for calculating embedment lengths in a hybrid coupled wall are developed as variations of the Prestressed Concrete Institute guidelines for steel brackets attached to reinforced concrete columns. In addition, experimental studies on the hybrid coupled shear wall were carried out. The main test variables were the ratios of the coupling beam strength to the connection strength. The test results indicate that it is more advantageous to design the coupling beams as shear yielding members since the shear-critical coupling beam exhibits a more desirable mode of energy dissipation than the flexure-critical coupling beam.     

Shear strength of the connection between a steel coupling beam and a reinforced concrete shear wall in a hybrid wall system

No specific guidelines are available for computing the shear strength of the connection between a steel coupling beam and a reinforced concrete shear wall in a hybrid wall system. There were carried out analytical and experimental studies on the connection between a steel coupling beam and a concrete shear wall in a hybrid wall system. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the shear strength of the connection between a steel coupling beam and a reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behaviour in the connection between a steel coupling beam and a shear wall, i.e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between a steel coupling beam and a reinforced concrete shear wall. The proposed equations in this study were in good agreement with both our test results and other test data from the literature.     

Experimental study on seismic behavior of steel column and steel plate RC composite wall coupled structure

钢柱与钢板混凝土组合剪力墙耦合结构体系是由钢板混凝土组合剪力墙及其两侧的钢柱通过钢连梁连接而成。该体系能够拓展“连梁-墙肢”耦合体系的应用范围，两侧钢柱“拉-压”力偶参与承担倾覆力矩，使得单肢墙体亦能获得双重抗震设防机制的保护。为研究钢柱与钢板混凝土剪力墙耦合结构体系的双重抗震机制，设计并制作一个耦连比0.45、缩尺比1/4的5层钢柱与钢板混凝土剪力墙耦合结构试件，对其进行低周往复加载试验，从滞回曲线、骨架曲线、刚度退化、延性、损伤特征等方面研究了该结构的抗震性能。基于ABAQUS有限元分析软件，对试验进行模拟。试验与分析结果表明：钢柱与钢板混凝土组合剪力墙耦合结构的顶层钢连梁及墙体分别在顶层侧向位移为21、65 mm时达到屈服状态，当顶层侧向位移为102 mm时，墙体底部形成塑性铰耗能，钢柱与钢板混凝土组合剪力墙达到预定的屈服顺序和破坏模式，实现了钢连梁 单肢剪力墙的双重抗震防线，发挥了联肢剪力墙的耦合机制。     

钢柱与钢板混凝土组合剪力墙耦合结构抗震性能试验研究

钢柱与钢板混凝土组合剪力墙耦合结构体系是由钢板混凝土组合剪力墙及其两侧的钢柱通过钢连梁连接而成。该体系能够拓展“连梁-墙肢”耦合体系的应用范围,两侧钢柱“拉-压”力偶参与承担倾覆力矩,使得单肢墙体亦能获得双重抗震设防机制的保护。为研究钢柱与钢板混凝土剪力墙耦合结构体系的双重抗震机制,设计并制作一个耦连比0.45、缩尺比1/4的5层钢柱与钢板混凝土剪力墙耦合结构试件,对其进行低周往复加载试验,从滞回曲线、骨架曲线、刚度退化、延性、损伤特征等方面研究了该结构的抗震性能。基于ABAQUS有限元分析软件,对试验进行模拟。试验与分析结果表明：钢柱与钢板混凝土组合剪力墙耦合结构的顶层钢连梁及墙体分别在顶层侧向位移为21、65 mm时达到屈服状态,当顶层侧向位移为102 mm时,墙体底部形成塑性铰耗能,钢柱与钢板混凝土组合剪力墙达到预定的屈服顺序和破坏模式,实现了钢连梁 单肢剪力墙的双重抗震防线,发挥了联肢剪力墙的耦合机制。     

Behavior of coupled shear walls with buckling‐restrained steel plates in high‐rise buildings under lateral actions

Traditional coupling beams in coupled shear walls (CSWs) may be lack of required ductility or inconvenient to be fully repaired or replaceable after earthquake damage. To improve the CSW seismic performance, a type of new structural system, which is referred to as coupled shear walls with buckling‐restrained steel plates (CSW–BRSP), is proposed and thoroughly studied. In the system, a pair of individual concrete wall is coupled through buckling‐restrained steel plates instead of traditional concrete coupling beams. Based on the continuous medium method (CMM), stiffness and strength design formulas are developed for the seismic design of this system. Intensive investigations have been conducted to assess the undesirable axial forces in the buckling‐restrained steel plates induced by lateral loads. In order to facilitate the application of this system, a detailed design procedure is also explicitly stated. Finally, an example of typical high‐rise building is presented to illustrate the design procedure as well as demonstrate the excellent seismic performance of the proposed system by means of nonlinear time‐history analysis. Copyright © 2015 John Wiley & Sons, Ltd.     

Seismic design method and experimental study of composite steel plate-concrete coupled shear wall systems

钢板混凝土联肢组合剪力墙是一种具有“双重防线机制”的优良抗震结构体系,其理论研究已经滞后于工程实践的发展,传统的基于强度的抗震设计方法难以从抗震耦合机制层面解决连梁和组合墙肢的匹配问题。为此提出以耦连比为基本设计参数,以连梁-墙肢“双重防线机制”为性能目标的钢板混凝土联肢组合剪力墙抗震设计方法。基于此方法,设计原型结构,并按原型结构底部五层的联肢墙设计制作1∶4缩尺试件,对试件施加往复荷载,考察试件的整体屈服机制。试验结果表明,结构体系通过钢连梁的剪切变形和墙肢底部的塑性铰变形来耗散能量,实现了连梁-墙肢“双重防线机制”,验证了该设计方法的合理性。     

A unified design approach for plate-reinforced composite coupling beams

Plate-reinforced composite (PRC) coupling beam is fabricated by embedding a vertical steel plate into a conventional reinforced concrete coupling beam to enhance its strength and deformability. Shear studs are welded on the surfaces of the steel plate to transfer forces between the concrete and the steel plate. Extensive experimental studies and numerical simulation have demonstrated the effectiveness and efficiency of this new type of coupling beam in resisting high shear force and large rotational demand from large wind or seismic loading. In this paper, an original and comprehensive design procedure is proposed to aid engineers in designing this new type of beam and to ensure proper beam detailing for desirable performance. The proposed design procedure consists of four main parts, which are (1) estimation of ultimate shear capacity of beam, (2) design of RC component and steel plate, (3) shear stud arrangement in beam span, and (4) design of plate anchorage in wall piers. Using the proposed procedure, the load-carrying capacity of the PRC coupling beams which were previously tested and simulated was evaluated. The results were compared with those from non-linear finite element analyses and experimental studies for validating the design procedure. A worked example is given to illustrate the design of PRC coupling beams using the proposed procedure.     

钢筋混凝土双肢剪力墙非线性静力有限元分析

利用有限元软件ABAQUS中的混凝土损伤塑性模型,采用分离式方法建立有限元模型,对钢筋混凝土双肢剪力墙进行了非线性分析;在与试验结果进行对比分析的基础上,选取了用于钢筋混凝土剪力墙非线性有限元分析的材料破坏准则和本构关系进行建模;通过数值计算,分析了轴压比、墙连梁跨高比、墙分布钢筋配筋率、边缘构件配筋率对钢筋混凝土双肢剪力墙的承载能力、延性、破坏形态等的影响。结果表明:轴压比、分布钢筋配筋率和连梁跨高比对钢筋混凝土双肢剪力墙的受力性能影响较为明显;边缘约束构件配筋率对墙体的影响较小。     

不同连梁节点构造的联肢钢板剪力墙结构抗震性能试验研究

为研究不同连梁节点构造时联肢钢板剪力墙结构的抗震性能,制作了3个缩尺比例为1∶3的联肢钢板剪力墙试件。试件中连梁与柱的连接分别采用隔板贯通式焊接节点、穿芯螺栓节点和悬臂梁段-端板节点,竖向边缘构件采用方钢管混凝土柱。对3个试件进行了拟静力试验,得到了联肢钢板剪力墙的滞回曲线、骨架曲线、特征荷载和位移等指标,分析了结构的延性、耗能能力、承载力及刚度退化等性能。结果表明,各试件位移延性系数均大于5.37,等效黏滞阻尼系数均大于0.211,刚度和承载力退化稳定,承载力退化系数均大于0.91。连梁节点的差异导致各试件的屈服顺序均不相同,采用穿芯螺栓连梁节点的试件,连梁先发生剪切屈服,耗能能力最优;采用悬臂梁段-端板连梁节点的试件,连梁与剪力墙板几乎同时屈服,耗能能力次之;采用焊接连梁节点的试件,连梁因节点焊缝断裂而破坏,试件初始刚度较高,承载力与耗能能力低于其他试件。总体上,各试件的剪力墙板与连梁均发生了较严重的破坏,实现了多道抗震设防的设计目标。     

钢骨混凝土连梁联肢剪力墙抗震性能试验研究及有限元分析

国内已有部分超高层建筑结构采用钢骨混凝土连梁联肢剪力墙,但现行规范尚未对其钢骨含钢率等控制参数给予明确规定。为此,对不同含钢率的钢骨混凝土连梁联肢剪力墙进行了低周反复荷载试验研究、ABAQUS有限元模拟以及变参数分析。分析结果表明：钢骨混凝土连梁联肢剪力墙试件的破坏模式、水平承载力、变形能力和耗能能力明显优于钢筋混凝土连梁联肢剪力墙;由ABAQUS参数分析结果可知,钢骨含钢率应控制在4%~8%之间,且宜增加连梁钢骨腹板的面积。     

Seismic behavior of coupled shear wall structures with various concrete and steel coupling beams

A novel 2‐level yielding steel coupling beam (TYSCB) has been developed to enhance the seismic performance of coupled shear wall systems. The TYSCB consists of a shear‐yielding beam designed to yield first under minor earthquakes and a bend‐yielding beam designed to yield under severe earthquakes. A comparison of seismic behavior of 4 20‐storey coupled shear wall structures with reinforced concrete coupling beams, complete steel coupling beams, fuse steel coupling beams, and TYSCB is presented. The dimensions and force‐displacement curves of these coupling beams are first designed. Nonlinear dynamic analyses on these structures are carried out under minor and severe earthquakes. The seismic behavior of these models is studied by comparing their storey shear forces, storey drift ratios and ductility demands. The results show that the base shear and storey drift of the structure with TYSCB under both minor and severe earthquakes are less than those of structures with concrete coupling beams and complete steel coupling beams. Furthermore, the ductility demand of coupled shear walls with TYSCB subjected to severe earthquakes can be greatly released compared with those using fuse steel coupling beams. This indicates that the proposed TYSCB has a better balance between ductility demand and energy dissipation, compared to traditional steel coupling beams.     

Stiffness analysis of concrete filled steel plate composite coupling beams

联肢剪力墙弹性阶段的内力分布、抗侧刚度等工作性能主要受墙肢与连梁刚度的影响。为了准确分析外包钢板-混凝土联肢组合剪力墙的受力性能,对外包钢板-混凝土组合连梁的刚度进行了分析。基于钢板与混凝土无相对变形和忽略混凝土抗拉强度的基本假定,建立了组合连梁钢与混凝土无滑移的截面内力与变形之间的关系,并推导了截面刚度的计算公式。对于常用工程设计参数范围内的组合连梁,考虑滑移后得到的抗侧刚度相比无滑移情况减小了10%~24%。通过对无滑移组合连梁刚度公式中的混凝土部分贡献的折减(折减系数为0.5),得到了无特殊界面构造的外包钢板 混凝土组合连梁的刚度计算公式。通过与有限元分析和试验结果的对比,验证了公式的准确性。     

钢连梁-钢板混凝土组合剪力墙组合件抗震性能试验研究

为进一步提高联肢剪力墙结构的抗震性能,提出了一种改进型钢连梁-钢板混凝土组合剪力墙混合结构.通过对5个1/2缩尺连梁-墙肢组合件的低周往复加载试验,研究了钢连梁跨高比和加劲肋布置等因素对组合件抗震性能的影响.研究表明:组合件塑性变形均集中在易更换的钢连梁上,墙肢和节点部位损伤程度较低,有利于实现结构罕遇地震作用后的功能...     

纵筋合并连接的装配式钢筋混凝土剪力墙平面内受力性能

钢筋混凝土剪力墙的钢筋数量较多而直径较小,装配时钢筋的连接工作量大且质量不易保证,纵筋合并连接是一种可能的解决方案。基于剪力墙截面设计方法分析了纵筋合并连接的可行性;通过3个剪力墙试件的拟静力试验验证了纵筋合并连接的有效性;采用有限元模拟方法分析了不同纵筋合并连接的装配式钢筋混凝土剪力墙受力性能。结果表明：当连接钢筋截面面积（强度）不小于原配筋截面面积（强度）且沿墙长均匀分布时,纵筋合并连接的装配式钢筋混凝土剪力墙仍表现出较好的抗震性能;边缘构件纵筋合并连接的剪力墙延性可能降低,宜慎重采用;分布钢筋采用合并连接对剪力墙的平面内受力性能影响较小,是一种较合理的合并连接方式,但连接钢筋布置位置宜沿墙长均匀分布,而不应集中于中性轴附近;未考虑纵筋合并连接对装配式钢筋混凝土剪力墙平面外受力性能、墙体抗裂性能及抗冲击能力等的削弱,因此,在应用时要考虑到此局限性。     

Behaviour of embedded steel plate in composite coupling beams

Plate-reinforced composite (PRC) coupling beam is fabricated by embedding a vertical steel plate into a conventional-reinforced concrete coupling beam to enhance its strength and ductility. Shear studs are welded on the steel plate surfaces to allow for proper load transfer between the concrete and steel plate. The present study focuses on the evaluation of internal load distributions and load sharing on the embedded steel plate as well as at the shear studs in composite coupling beams using the nonlinear finite element package ATENA. The proposed two-dimensional finite element model is able to simulate the overall load-deflection behaviour and internal load distributions of coupling beams subjected to bending and shear forces. The reliability of the model is demonstrated by comparisons with the available experimental results. This is followed by an extensive and carefully planned parametric study using the calibrated finite element model. Numerical results on the effects of steel plate geometry, span-depth ratio of beams and steel reinforcement ratios at beam spans and in wall regions are presented and discussed in this paper. The finite element model provides a better understanding of the behaviour of shear studs as well as plate anchorage in the wall regions and embedded beam region. Based on the numerical results, equations for quantifying the shear stud forces are established and a set of non-dimensional design charts for determining the internal forces of the embedded steel plates is constructed. Both of them are useful for engineers to design PRC coupling beams.     

钢管混凝土边框钢纤维混凝土剪力墙受剪承载力计算

通过5个钢管混凝土边框钢纤维混凝土剪力墙和1个钢管混凝土边框混凝土剪力墙的低周反复加载试验,研究钢管混凝土边框钢纤维混凝土剪力墙的受力机理及破坏模式,分析钢纤维体积率和混凝土强度对其抗震性能的影响。结果表明：钢管混凝土边框钢纤维混凝土剪力墙的破坏模式为剪切破坏;墙体裂缝主要为典型的斜裂缝,钢纤维可有效限制剪力墙裂缝宽度,改善裂缝形态;随着钢纤维体积率的增大,剪力墙受剪承载力、延性和耗能能力明显提高;其他影响因素相同的条件下,钢纤维体积率为0.5%、1.0%和1.5%的剪力墙受剪承载力较未掺钢纤维剪力墙的分别提高了4.4%、12.7%和18.6%;随着混凝土强度的提高,剪力墙受剪承载力和耗能能力明显提高,但延性降低;其他影响因素相同的条件下,钢纤维混凝土强度等级为CF60、CF80剪力墙的受剪承载力较CF40剪力墙的分别提高了24%和37%。结合对文中及国内外相关文献试验数据的综合分析,提出了考虑钢纤维体积率和混凝土强度等影响的钢管混凝土边框钢纤维混凝土剪力墙受剪承载力计算方法,与试验结果吻合较好。     

钢板混凝土剪力墙抗剪性能试验研究

完成了2个内嵌钢板混凝土墙试件和3个外包钢板混凝土墙试件在恒定轴压力和往复剪切作用下的拟静力试验,用以研究钢板混凝土剪力墙的抗剪性能。墙试件采用工字形截面,剪跨比为1.2,腹板墙截面含钢率约6%。试验结果表明：试件腹板墙发生剪切破坏;当设计轴压比由0.3提高至0.6时,试件的受剪承载力略有提高,极限位移角减小约20%;在轴压比相同和腹板墙含钢率相近的情况下,外包钢板混凝土墙的变形能力比内嵌钢板混凝土墙大约20%;采用竖向加劲肋-缀条拉结代替栓钉-对拉螺栓连接,外包钢板混凝土墙的受剪承载力差异不大,但变形能力显著增大。对国内外46个钢板混凝土墙试验数据的分析表明,按中国规程 JGJ 3-2010《高层建筑混凝土结构技术规程》计算得到的受剪承载力平均为试验值的78%,计算公式偏于安全;而美国规范AISC 341-10和欧洲规范Eurocode 8的计算公式仅考虑钢板的抗剪贡献,计算值仅为试验值的51%,严重低估了钢板混凝土墙的受剪承载力。对大量剪力墙试验数据的分析表明,钢板混凝土墙的剪切变形能力显著优于钢筋混凝土墙和钢骨混凝土墙。     

连梁破坏模式与安全状态的简化判断

作为剪力墙结构中的主要耗能构件,连梁在剪力墙的抗震性能研究中占有重要地位,对连梁破坏状态的研究就显得十分重要。归纳了连梁的4种破坏模式,提出简化公式分别根据连梁的耦联率和连梁的破坏形式区分模式,并判断连梁的安全状态。     

连梁内设置竖向变形阻尼器的耗能剪力墙体系减震分析与设计

将钢筋混凝土联肢剪力墙在连梁跨中开缝,在缝中设置沿竖向变形的钢阻尼器,从而形成耗能联肢剪力墙体系。在强震作用下,耗能剪力墙中的阻尼器一方面适当削弱联肢剪力墙刚度以降低地震作用,另一方面阻尼器屈服后可耗散部分地震能量,从而减小墙肢及连梁的塑性损伤。将阻尼器与连梁组合为等效连梁,运用等效连续化方法对耗能剪力墙体系的刚度特性与阻尼特性进行了简化分析,对耗能剪力墙体系的减震机理进行了论证,并推导出体系关键参数的计算式。以阻尼器延性系数和联肢墙耦合比为设计控制指标,提出了该耗能剪力墙体系基于性能/需求的设计方法。设计实例表明：所提出设计方法简便可行;在参数设计合理的情况下,建议的耗能剪力墙体系具备良好的减震效果。