Seismic performance of l‐shaped rc shear wall subjected to cyclic loading

Shear wall systems are one of the most commonly used lateral‐load resisting systems in high‐rise buildings. The height–thickness ratio of traditional RC shear wall is more than 8. In order to study the seismic performance of a new type of shear wall structure (short‐limb shear wall structure) with height–thickness ratio of 5–8, L‐shaped cross‐section. A total of six shear wall specimens with 1/2‐scaled model were tested under the cyclic loading. The test parameters included: six specimens were loaded in the web plane; axial–load ratio and height‐thickness ratio were in the range of 0.1–0.4 and 5–8, respectively. The failure process, failure mode and deformation properties were studied. The test results are shown that: L‐shaped RC shear wall with a better deformation than the traditional shear wall, when the axial‐load ratio and height‐thickness ratio are within a certain range, the seismic performance will be able to play to the best. Specimens of the axial‐load ratio of 0.1, height‐thickness ratio of 6.5, they have the most excellent ductility and energy dissipation capacity. Copyright © 2010 John Wiley & Sons, Ltd.     

基于性能的钢筋混凝土剪力墙受弯破坏变形限值的研究

为了确定钢筋混凝土剪力墙构件在不同性能状态下的变形能力,根据基于性能的抗震设计理论,结合20世纪70年代以来国内学者在钢筋混凝土剪力墙延性方面的试验研究结果,对120片以受弯破坏为主的钢筋混凝土剪力墙试件在不同性能状态下的延性性能进行分析,同时结合国内外规范中的相关规定,分别推导和拟合出剪力墙试件在各性能目标下截面曲率和塑性位移角的计算公式。同时根据地震超越概率分布特点得出适合GB 50011-2001《建筑抗震设计规范》（2008年版）的、轴压比为0≤n≤0.4的剪力墙在各性能目标下塑性位移角限值,并与美国相关规范中对应的目标位移限值进行比较和分析,为我国基于性能的钢筋混凝土剪力墙抗震设计提供相关参考。     

基于试验的型钢混凝土柱抗震性能指标限值研究

收集了206个国内外型钢混凝土(SRC)柱试验结果,分析研究剪跨比、弯剪比、轴压力系数、体积配箍率和配钢率5个主要参数对SRC柱破坏形态的影响,提出以剪跨比、弯剪比划分SRC柱破坏形态的方法。根据现行抗震设计规范和SRC柱的试验破坏过程确定SRC柱的5个性能状态,以构件骨架曲线为基础得到构件各性能状态的位移角限值。在不同破坏状态下,分析各性能状态位移角限值和5个主要参数的关系,得到轴压力系数是影响构件位移角限值变化的关键参数,统计得到与SRC柱5个性能状态对应的变形指标限值,并进行可靠性分析。结果表明该文所给出的破坏形态划分方法能够较好的预测不同的破坏形态|根据轴压力系数给出的SRC柱变形指标限值的保证率在合理范围之内。     

纤维增强混凝土剪力墙抗震性能试验研究与理论分析

为根本改善混凝土基体的脆性,提高混凝土剪力墙的抗震性能和损伤容限,设计制作6个局部纤维增强混凝土（FRC）剪力墙试件,在试件变形关键部位采用FRC替代普通混凝土,并考虑高轴压比下剪力墙受压钢筋屈曲和受拉纵筋应力集中的问题,在塑性铰区纵向钢筋上设置钢套管,以改善受力钢筋的稳定性和变形性能。通过对悬臂剪力墙试件的拟静力试验,研究此类剪力墙的破坏现象、受力机理和滞回特性,探讨轴压比、FRC区高度、纵筋强度和钢套管长度等因素对墙体变形能力及耗能能力的影响。研究表明,与普通混凝土剪力墙试件相比,塑性铰区采用FRC的剪力墙试件具有较高的损伤容限和变形能力;提高钢筋强度和延性以及在纵筋上设置钢套管,对其抗震性能和耗能能力均具有明显的改善作用。     

Cumulative damage model of mid‐rise shear wall and its experimental verification

The study concentrated on investigating the relationship of the continuous cumulative damage, macroscopic deformation development and failure process of mid‐rise shear walls. Nonlinear fiber element model considering the effect of cumulative damage is proposed for evaluating the seismic performance of shear wall. Numerical analyses of shear wall specimens are carried out according to the proposed model to obtain the evolution of damage index of the shear wall. Experiments of six L‐shaped shear wall specimens subjected to reversed cyclic loading are carried out to verify the proposed model. Correlation of damage index and performance level is established, which provides good reference for the safety assessment of the structure under seismic type of loading. The model is efficient to evaluate the seismic performance of shear wall proved by the satisfactory agreement between analytical and experimental results. Copyright © 2012 John Wiley & Sons, Ltd.     

钢筋混凝土剪力墙变形性能指标试验研究

为研究矩形截面钢筋混凝土剪力墙变形指标,根据GB 50011—2010《建筑抗震设计规范》设计了20个剪力墙试件进行低周往复荷载试验,研究不同剪跨比、试验轴压比、边缘构件纵筋配筋率对矩形截面剪力墙破坏形态、滞回性能、变形能力的影响。试验结果表明：随着剪跨比减小,剪力墙的破坏形态由弯曲破坏转向剪切破坏;随着试验轴压比增大,剪力墙的延性降低;随着边缘构件纵筋配筋率提高,弯曲破坏剪力墙延性提高,弯剪破坏与剪切破坏剪力墙延性降低。根据试验结果,建立了构件变形-构件损坏程度-构件承载能力的关系,提出了基于骨架曲线和破坏现象两种性能状态划分方法,得到剪力墙的变形性能指标,并将两种方法的结果进行对比,结果表明两者较为吻合,验证了基于骨架曲线划分性能状态方法的合理性与有效性。     

Cyclic loading test of T‐shaped mid‐rise shear wall

Shear wall systems are the most commonly used lateral load resisting systems in high‐rise buildings. Six 1:2 scale mid‐rise T‐shaped reinforced concrete shear wall specimens with aspect ratio of 1.75, 2.15 and 2.80 were respectively tested under reversed cyclic loading. The seismic behavior and displacement ductility were investigated. The effects of aspect ratio, axial load level and transverse steel ratio on the seismic behavior and displacement ductility were also analyzed. Test results were discussed and compared with T‐shaped steel–concrete composite shear wall. Results mainly showed that the T‐shaped shear wall specimens mainly presented bending–shear failure mode and were all destroyed because of the concrete crushing at the web (negative direction) and the longitudinal reinforcement of the web reaching the limited deformation (positive direction), showing that the web was the weakest part of T‐shape shear wall. The ductility of the specimens was decreased, and the ultimate load‐bearing capacity was increased by increasing the axial load. To specimens with smaller aspect ratio and higher axial load ratio, the special transverse steel ratio of the web should be increased to improve the crushing strain of the confined concrete of the web in order to satisfy the ductility of the walls. The seismic performance was obviously improved in the T‐shaped steel–concrete shear wall compared with that of the T‐shaped reinforced concrete shear wall. Copyright © 2011 John Wiley & Sons, Ltd.     

Evaluation of deformation capacity including yield deformation in displacement‐based design of special RC shear wall

A displacement‐based design scheme can be applied to the seismic designs of special reinforce concrete (RC) shear walls. However, the displacement‐based design in the current seismic design codes does not consider the contribution of yield deformation of RC shear walls. In this study, the evaluation method of the deformation capacity for seismic designs of RC shear walls was analyzed and applied to a parametric study for the lateral deformations of RC shear walls. From the results of analyses with various design conditions, the contribution of yield deformation to the deformation capacity of an RC shear wall was analyzed. It was demonstrated that, for RC shear walls in tall buildings, the yield deformation increased as the ratio of wall height to length increased and reached more than 50% of total deformation. Therefore, for the reasonable design of special RC shear walls in tall buildings, the design equation including the yield deformation in the displacement‐based design process is proposed. Copyright © 2012 John Wiley & Sons, Ltd.     

内置轻钢桁架混凝土组合剪力墙抗震性能试验研究

将冷弯薄壁型钢桁架配置在普通钢筋混凝土剪力墙中代替钢筋而形成轻钢桁架混凝土组合剪力墙。为研究该类墙体的抗震性能,对两组共6个内置轻钢桁架混凝土组合剪力墙进行拟静力试验,研究轴压比和斜撑体积配钢率对其滞回性能、变形性能、刚度退化以及耗能能力的影响。对比了低矮剪力墙和中高剪力墙的位移延性和耗能能力。结果表明：轴压比对该类剪力墙的变形能力和耗能能力均不利,应予以控制;斜撑体积配钢率对提高低矮墙的延性、耗能能力效果明显,但对承载力的提高作用较小;对中高剪力墙,斜撑体积配钢率的增加,对其耗能能力不利。     

钢-混凝土组合核心筒的变形性能指标限值研究

以国内28个核心筒的拟静力试验数据为基础,按骨架曲线和破坏现象两种性能状态划分方法得到了核心筒的变形性能指标,并将两种方法所得到的结果进行对比,验证了基于骨架曲线划分性能状态方法的合理性。基于OpenSees软件平台并通过与试验结果对比验证,建立了核心筒的有限元模型并据此进行参数分析,得到了各性能状态的位移角限值,分析了轴压比、高宽比、连梁跨高比、钢板暗支撑含钢率、暗柱含钢率和角部含钢率对钢-混凝土组合核心筒在不同性能状态下位移角的影响。研究结果表明:轴压比与连梁跨高比对变形性能指标限值影响明显,增大钢板暗支撑含钢率能提高变形能力,高宽比和暗柱、角部含钢率对各性能等级的变形指标限值影响较小。对有限元分析结果进行统计分析,得到了钢-混凝土组合核心筒在各性能等级的变形指标限值,可为抗震性能设计提供参考。     

钢筋混凝土剪力墙构件地震损伤性能试验

为了研究剪力墙的地震损伤和基于位移的抗震性能设计,对7片不同设计参数的钢筋混凝土剪力墙构件进行了低周反复加载试验,记录了构件各损伤阶段的变形和裂缝宽度。根据试验结果,对比研究了轴压比、边缘构件配箍率、截面形式对剪力墙构件延性、承载力、变形特点和地震损伤的影响规律。研究结果表明:随着轴压比增大,构件承载力增大,剪切效应增大,延性降低,残余裂缝率减小;随着变形的增大和损伤加剧,构件剪切效应增强;工字形截面构件剪切效应更明显,裂缝开展较慢。     

工字形钢筋混凝土剪力墙变形指标试验研究

根据我国现行规范要求,设计20个工字形RC剪力墙试件进行低周往复试验,各片墙体的主要变化参数为剪跨比、边缘构件的纵筋配筋率、设计轴压比,对其破坏形态、滞回特性、位移延性进行研究。根据试验结果,分别采用基于骨架曲线和基于试验现象的方法给出20个试件在完好、轻微损坏、轻中等破坏、中等破坏、较严重破坏、严重破坏6个性能状态对应的变形限值,最后,对比同批20个矩形RC剪力墙的试验结果,分析翼缘对RC剪力墙构件变形限值的影响。结果表明,基于骨架曲线划分得到的性能状态具有明确的破坏现象,是合理的;设置翼缘的工字形剪力墙的变形能力强于矩形剪力墙。     

高层屈曲约束钢板墙-混凝土框架结构抗震性能研究

为研究高层屈曲约束钢板墙-混凝土框架结构的抗震性能,分别设计了一个10层钢筋混凝土框架结构和屈曲约束钢板墙-混凝土框架结构模型,进行了地震作用下动力非线性分析。结果表明：屈曲约束钢板墙可显著减小高层钢筋混凝土框架结构在地震作用下的层间位移,同时在罕遇地震作用下框架中塑性铰的数量也有大幅减少,表现出良好的抗震性能。在此基础上,综合规范对框架结构和框架-抗震墙结构抗震等级和柱轴压比限值的规定,并结合屈曲约束钢板墙-混凝土框架结构的受力特点,提出了高层屈曲约束钢板墙-混凝土框架结构的抗震设计建议。建议屈曲约束钢板墙的边缘构件按框架结构确定抗震等级和柱的轴压比限值,其他框架部分根据其承担的地震倾覆力矩比例大小,按框架结构或框架-抗震墙结构确定抗震等级和柱的轴压比限值。     

基于纤维梁柱单元的RC带翼缘剪力墙抗震性能分析

为高效准确地模拟钢筋混凝土构件在复杂荷载作用下非线性行为,采用OpenSees中基于刚度法的纤维梁柱单元,建立一种考虑弯曲和剪切共同作用的RC带翼缘剪力墙非线性分析模型,并对已完成的4个不同边缘构件和截面形式的RC带翼缘剪力墙的拟静力试验进行数值模拟;通过比较数值模拟结果与试验结果,验证有限元模型的准确性;通过有限元分析,研究轴压比(0.1~0.3)、剪跨比(1.8~3.0)、翼缘宽度与腹板高度比(0.5~1.1)、混凝土强度(C30~C45)、纵筋配筋率(0.73%~2.22%)以及箍筋配箍率(0.74%~5.19%)对RC带翼缘剪力墙抗震性能的影响。研究表明：随着轴压比、翼缘宽度与腹板高度比、混凝土强度以及纵筋配筋率的增大,带翼缘剪力墙的承载力逐渐增大,其极限变形能力在翼缘受拉方向也相应增大,而在翼缘受压方向不断减小。剪跨比的增大使得带翼缘剪力墙的承载力明显减小,但是变形能力大幅提高。箍筋配箍率的提高可以有效延缓带翼缘剪力墙翼缘受拉方向的破坏。     

装配整体式钢筋混凝土剪力墙子结构抗震性能试验研究

对一栋3层足尺的新型装配整体式混凝土剪力墙子结构进行拟静力试验。该结构中包含4种连接构造,即同层同跨内预制墙的竖缝采用干式连接,同层相互垂直墙体间采用现浇转角墙连接,上、下预制墙间采用型钢抗剪键和后浇型钢边缘构件2种连接构造进行连接。试验结果表明：该类型装配整体式型钢剪力墙结构具有良好的抗震性能;连梁在整个抗侧力体系中起到第一道防线的作用,加载结束时,连梁发生明显剪切破坏,具有较强的耗能能力;干式连接在试验中陆续进入屈服,可作为结构的第二道耗能防线;试验后期,部分干式连接的焊缝出现断裂,无法继续限制墙肢对楼板的冲切作用。型钢边缘构件和后浇RC转角墙中的纵筋分别在层间位移角达到1/150和1/100时发生屈服;整体模型在层间位移角达到1/75后,未出现承载力失效或楼板构件脱落现象,可认为该结构体系的抗震性能等同于现浇剪力墙结构。     

CFRP筋/钢筋混凝土剪力墙抗震性能试验

为研究不同轴压比和边缘构件中的箍筋形式对碳纤维增强复合材料(CFRP)筋/钢筋混凝土剪力墙抗震性能的影响,设计了6个剪跨比为2.0的CFRP筋/钢筋混凝土剪力墙,其中3个剪力墙的边缘构件中配置矩形复合箍筋,另外3个剪力墙的边缘构件中配置圆形箍筋,完成了轴压比分别为0.17,0.26,0.33的剪力墙低周反复荷载试验,研究了剪力墙滞回曲线和骨架曲线的特征、强度和刚度退化规律及耗能能力等。结果表明:轴压比和边缘构件中的箍筋形式对剪力墙抗震性能影响较大,随着轴压比的增大,剪力墙承载能力和耗能能力增大,刚度退化程度减缓,但是极限荷载对应的变形和极限变形有所降低;箍筋形式对剪力墙的极限承载力影响较小,但是配置矩形复合箍筋的剪力墙比配置圆形箍筋剪力墙有较大的极限变形,累积耗能能力也较高;轴压比较大时,剪力墙的裂缝发展高度减小,墙角混凝土破坏区域增大,配置圆形箍筋剪力墙墙角混凝土破坏区域和破坏程度比配置矩形复合箍筋的剪力墙大;所有剪力墙的残余变形较小,自复位性能良好。     

Fragility assessment of high‐rise reinforced concrete buildings considering the effects of shear wall contributions

The effect of shear wall configurations on seismic responses of high‐rise RC buildings is investigated in this paper using fragility analysis method. Four lower high‐rise RC buildings that have the same plan dimensions and height but are different in configurations in lateral force resisting systems, were firstly designed following the standard code procedure. To consider uncertainties in earthquake motions, 16 real ground motion pairs were selected and scaled, then applied orthogonally to the four RC building models during the Incremental Dynamic Analysis (IDA). Fragility relationships were therefore derived based on the IDA results for the three limit states including slight damage, moderate damage and collapse to show the probabilistic comparison of seismic responses among the four buildings in both x and y‐directions. It was observed that generally adding shear walls will improve buildings' seismic performance at all limit states. However, shear wall configuration also plays a significant role in seismic behavior of the lower high‐rise regular RC buildings' and internal shear walls are generally more effective than external shear walls in improving building's seismic resistance. Copyright © 2016 John Wiley & Sons, Ltd.     

冷挤压套筒连接RC装配式剪力墙抗震性能试验研究

为解决RC装配式剪力墙钢筋连接施工和质量检验困难的问题,提出了一种采用冷挤压套筒钢筋连接方式的装配式剪力墙构造形式.为探明此连接方式装配式剪力墙的可行性及其抗震性能,完成7个装配式剪力墙试件和2个现浇剪力墙对比试件的拟静力试验.对试件的水平荷载-侧移曲线及其特征点、钢筋应变进行了分析.结果 表明:装配式剪力墙试件和现浇...     

拉压变轴力下小剪跨比预应力混凝土墙往复受剪试验研究

为了研究预应力混凝土（PC）剪力墙的抗震性能,提出剪力墙在拉压变轴力作用下的水平往复加载试验加载制度,完成3片剪跨比为1.0的预应力混凝土墙在恒定轴拉力、恒定轴压力和拉压变轴力作用下的水平往复加载试验,研究其破坏模式、滞回性能、承载力、变形能力、刚度和残余裂缝宽度,并与型钢混凝土（SRC）墙和普通RC墙的抗震性能进行了对比。试验结果表明：恒定轴拉力试验中,预应力混凝土墙发生了腹板剪切破坏;恒定轴力试验中墙体发生了斜压破坏;拉压变轴力试验中,墙体在压剪方向加载时发生剪压破坏。拉压变轴力加载导致预应力混凝土墙拉剪和压剪承载力分别降低了18.7%和10.5%。预应力混凝土墙在恒定轴拉力和拉压变轴力作用下的极限位移角为1.2%~1.6%,变形能力大于JGJ 3—2010《高层建筑混凝土结构技术规程》规定的弹塑性位移角限值(1/100);恒定轴压力试验中水平峰值荷载超过了墙体截面受剪承载力限值,出现斜压破坏,极限位移角仅为0.6%。预应力混凝土墙试件与SRC墙试件的刚度、承载力和变形能力接近,前者的残余裂缝宽度小于后者的,表现出更好的震后可修复性。由于预应力有效抑制了墙体水平贯通裂缝的形成、防止出现沿水平裂面的滑移破坏,因此在较大轴拉力水平时预应力混凝土墙比普通RC墙的抗侧刚度和承载能力均显著提高。总体来看,预应力混凝土墙抗震性能优良,是一种改善高层建筑中受拉剪力墙抗震性能的有效手段。     

高轴压比钢骨混凝土剪力墙抗震性能试验研究

为研究高轴压比钢骨混凝土剪力墙的抗震性能,完成了6片剪跨比为2.43、轴压比试验值为0.33~0.35的钢筋、钢骨和钢管混凝土剪力墙试件的往复水平力加载试验。试验表明:试件的纵筋和钢骨(钢管)受压屈服先于受拉屈服。试件的破坏形态为底部混凝土压碎剥落,约束边缘构件内的纵筋和钢骨(钢管)压曲,试件丧失竖向承载力。钢骨和钢管提高了试件的正截面承载力,且随位移增大试件能稳定地保持最大承载力。配置工字钢、槽钢和方钢管的试件的极限位移角为1/73~1/59,与钢筋混凝土试件基本相同;配置圆钢管的试件的极限位移角达1/44,墙端约束边缘构件配置圆钢管对提高高轴压比剪力墙的变形能力有显著作用。根据试验结果,提出了高轴压比钢骨混凝土剪力墙屈服、承载力极限状态和变形极限状态的截面应变、应力分布,建立了正截面承载力的计算式和顶点水平位移计算式,计算结果与试验结果符合较好。