底层大空间剪力墙结构12层模型的试验研究

为研究底层大空间剪力墙结构的设计方法,进行了12层结构模型(1/6缩尺)的试验研究。本文介绍弹性阶段试验结果,其中包括;结构在竖向及水平荷载作用下的应力分布和变形特点、楼板变形的影响、结构的动力特性。并将理论分析与实测结果作了比较。     

带暗支撑短肢剪力墙结构振动台试验研究

提出了钢筋混凝土带暗支撑短肢剪力墙结构体系。进行了1个1/6缩尺的带暗支撑短肢剪力墙结构模型与1个1/6缩尺的普通短肢剪力墙结构模型模拟地震振动台试验研究。通过试验,分析了两个模型在弹性、开裂、破坏各阶段的动力特性及动力反应,比较了两个结构模型的破坏形态。试验结果表明:在弹性阶段,两结构的动力特性及动力反应相近;在混凝土开裂后的弹塑性阶段,带暗支撑短肢剪力墙结构与普通短肢剪力墙结构相比,其抗震能力显著提高,层间位移及结构顶点位移峰值显著减小;带暗支撑短肢剪力墙结构墙肢底部塑性铰区域比普通短肢剪力墙结构塑性铰区域显著增大,抗震耗能能力显著提高。建立了结构弹性和弹塑性有限元时程分析力学模型,进行了结构的时程动力计算分析,计算结果与试验结果符合较好。     

剪力墙结构模型动力试验分析

本文通过对8层剪力墙结构模型(1/20缩尺)在振动台上进行试验,研究了剪力墙结构的动力特性、弹塑性反应、连接构造的可靠性和破坏特征。以试验值和按分层模型弹塑性动力分析的计算值相比较,两者很接近。研究结果表明高层建筑剪力墙结构只要有合理的构造、适当的配筋率,抗震性能是良好的。     

钢板剪力墙抗震性能试验研究

以天津国际金融会议酒店工程为背景对钢板剪力墙的抗震性能进行试验研究。完成了3个4层1∶5缩尺比例的钢板剪力墙试件的拟静力试验。试件主要变化参数包括墙板开洞和中柱设置。试件SPSW-1墙板开洞,试件SPSW-2墙板不开洞,试件SPSW-3带有中柱,且中柱一侧墙板开洞。在钢板剪力墙的墙板上布置了槽形和一字形两种截面形式的加劲肋。试验结果表明：钢板剪力墙结构具有良好的承载力、延性和耗能能力;开洞降低了钢板剪力墙结构的刚度和承载力;中柱提高了钢板剪力墙结构的刚度和承载力;加劲肋可增强钢板剪力墙结构的刚度和稳定承载力,开洞补强效应显著。     

底层大空间带暗支撑剪力墙结构振动台试验研究

进行了2个1/8缩尺的底层大空间部分框支剪力墙结构模型(其中一个模型的两片落地剪力墙配有暗支撑)的振动台试验,试验结构经历了弹性阶段、开裂直至破坏全过程,研究了结构在各个阶段的动力特性变化及动力反应,比较了两个结构模型的破坏形态,进行了弹性和非线性有限元时程反应分析。试验及分析结果表明,在混凝土开裂前的弹性阶段,带暗支撑剪力墙结构的抗震性能与普通剪力墙结构基本相同;在混凝土开裂后的弹塑性阶段,带暗支撑剪力墙结构的结构抗力明显大于普通剪力墙结构的结构抗力,带暗支撑剪力墙结构模型的底层最大层间位移反应比普通剪力墙结构模型的底层最大层间位移反应显著减小,带暗支撑剪力墙与普通剪力墙的破坏形态不同,带暗支撑剪力墙底部塑性铰区的高度显著大于普通剪力墙底部塑性铰区的高度。     

带缝空心RC剪力墙结构动力特性试验研究及仿真分析

为了研究带缝空心钢筋混凝土剪力墙结构房屋的动力特性,进行了缩比为1∶3的6层模型房屋的动力特性试验及拟动力试验,获得了结构的周期、振型、阻尼比、动力放大系数等动力特性参数。在试验研究的基础上,利用有限元分析软件ANSYS对结构模型进行了模态分析,试验结果与ANSYS模拟结果吻合较好。研究结果表明,带缝空心钢筋混凝土剪力墙结构是一种介于框架结构和传统剪力墙结构的新型结构形式。     

中高层开洞剪力墙双肢变形特性分析的正交分解法

开洞剪力墙的双肢变形特性是进行抗震设计所要考虑的重要因素之一。在正交理论的变形分解基础上,实现对开洞剪力墙振型的精细识别,得到了振型相对变形分解图;进而,通过引入双肢系数,给出了开洞剪力墙振型双肢特性的量化判据;由于振型是结构完备的变形基,该方法可为剪力墙的刚度设计提供技术支持。对8层和16层钢筋混凝土开洞剪力墙试验模型的分析表明,在整体小开洞剪力墙和联肢剪力墙中间存在一种中间状态,该状态的剪力墙在横向静力作用下表现出整体变形特性,在水平地震作用下则可能表现为双肢变形特性,对此,在抗震设计中应引起足够的重视。     

高位转换消能减震结构振动台试验研究

某超限高层建筑采用钢筋混凝土框架-剪力墙结构,存在高位转换层,其楼板平面开洞尺寸过大,造成楼板平面刚度不连续。弹性分析时,楼层竖向构件最大水平位移与楼层水平位移平均值之比为1.31,属结构扭转不规则,为此结构设计采用了软钢阻尼器来提供附加刚度及阻尼。为研究该高层建筑结构抗震性能,进行了1∶20缩尺模型的振动台试验,获得了模型结构的动力特性及在地震作用下的动力反应,分析了原型结构的地震反应。试验及分析结果表明,该结构满足现行建筑抗震设计规范的抗震设防要求;阻尼器减小了结构的扭转反应,对加速度反应起到了一定的减小作用;转换层上刚度变化较大,应逐步减缓刚度变化,改善相邻楼层的延性;出屋面层的鞭梢效应严重,应重视出屋面层的抗震设计。     

方钢管混凝土框架-中间开洞薄钢板剪力墙的力学性能研究

进行了一榀1/3比例单跨两层方钢管混凝土框架-中间开洞薄钢板剪力墙的低周反复荷载试验,研究了钢板剪力墙中间开洞对方钢管混凝土框架-薄钢板剪力墙抗震性能的影响。利用有限元软件ABAQUS对方钢管混凝土框架-中间开洞薄钢板剪力墙进行了数值分析,研究了钢板剪力墙开洞位置、洞口宽度比、钢板剪力墙厚度以及加劲肋等对其力学性能的影响。结果表明:开洞位置的变化对结构影响很小;增大钢板剪力墙洞口宽度比降低了结构的承载能力和初始刚度;增大钢板剪力墙厚度提高了结构的承载能力和初始刚度;通过在洞口周边设置加劲肋,减小了钢板剪力墙的高厚比,减弱了钢板剪力墙对竖向边缘构件的影响。     

带缝空心R.C.剪力墙结构模型动力特性研究

为了研究带缝空心钢筋混凝土结构房屋的动力特性,进行了1∶3.0模型6层结构房屋的模态试验及拟动力试验,获得了结构的周期、振型、阻尼比、动力放大系数等动力特性参数。在试验研究的基础上,利用有限元分析软件ANSYS对结构模型进行了模态分析。研究结果表明,带缝空心钢筋混凝土剪力墙结构是一种介于框架结构和传统剪力墙结构之间的新型结构形式。试验结果与ANSYS模拟结果吻合较好,利用ANSYS软件进行仿真分析是测试结构动力特性的一种可靠方法。     

钢板外包混凝土剪力墙板抗剪滞回性能试验研究

钢板外包混凝土预制装配式剪力墙板是在钢板剪力墙板基础上提出的一种用于高层建筑钢结构的新型抗侧力构件。它以普通钢板作为基本支撑板，钢板上、下分别与钢框架中的梁相连，两侧外包混凝土为钢板提供侧向约束，防止钢板过早屈曲失稳，同时混凝土还起到防火隔热的作用。本文通过对３个钢板外包混凝土剪力墙试件和１个纯钢板剪力墙板试件的模型试验，研究了在低周反复加载下钢板外包混凝土剪力墙板的破坏形态、延性、抗剪强度和刚度等。试验表明，钢板外包混凝土剪力墙与钢板剪力墙相比，具有良好的稳定性能和延性性能，同时其刚度和强度也大大提高。     

小剪跨比保温砌模混凝土墙抗震性能试验研究

8片剪跨比为0.77、0.84和1.0的保温砌模混凝土墙的抗震性能试验结果表明,小剪跨比保温砌模混凝土墙在竖向力和往复水平力作用下,连梁剪切破坏,端墙肢边缘混凝土受压破损;位移延性系数不小于3;极限位移角大于1/120。保温砌模混凝土墙的受剪承载力可按现行规范剪力墙有地震作用组合的受剪承载力公式(扣除洞口的截面面积)计算。有限元分析结果表明,保温砌模混凝土墙的抗侧刚度可用厚度为其三分之二的等效实体墙计算或用小开口整体墙计算。工程算例表明,保温砌模现浇承重墙体系满足8度抗震设防的7层住宅层间位移角要求和受剪承载力要求。     

钢筋混凝土水平拼接叠合剪力墙抗震性能试验研究

通过对3片钢筋混凝土水平拼接叠合剪力墙、1片钢筋混凝土整体叠合剪力墙和1片钢筋混凝土全现浇剪力墙进行抗震性能试验研究,对比研究了试件的裂缝发展情况及破坏形态,分析了试件的承载能力、滞回曲线、骨架曲线、刚度退化曲线、延性性能、耗能性能等。研究结果表明：水平拼接叠合剪力墙与整体叠合剪力墙以及全现浇剪力墙的受力过程、破坏模式基本相同,抗震性能指标相近,具有较好的抗震性能;水平拼接节点构造合理,水平拼接叠合剪力墙的承载能力不低于整体叠合剪力墙;剪式支架能使钢筋混凝土叠合剪力墙的预制部分与现浇混凝土形成整体,协同工作承受外部荷载。     

Experimental study on separating reinforced concrete infill walls from steel moment frames

In a multistory building frame, stiff reinforced concrete (RC) infill walls may be terminated above the first story for architectural purposes, which may create a soft-first-story structure. To eliminate this detrimental situation, this paper proposes to separate the RC infill wall from the steel moment frame by slits. An experimental program of four one-bay-by-one-story steel moment frame specimens along with pushover analyses of multistory frame models were presented to validate the proposed idea. This study conducted cyclic loading tests on a total of four moment-resisting-frame specimens, which included one bare frame; one with ordinary RC infill wall; and two with side slits between RC wall and frame members. Furthermore, pushover analyses of multistory frame models with soft first story configurations were also conducted to illustrate the effect of RC infill walls with or without slit separation. Both experimental and analytical results showed that the stiff RC infill wall dominated the lateral resistance and drift capacity of the test specimens, and that by adding slit-separated features at the edges of infill walls improved the drift capacity. It is concluded that the slit-separated features can be a viable option to eliminate the soft-story problem caused by vertically irregular configuration of RC infill walls.     

大网格混凝土剪力墙抗震性能试验研究

为适应不超过6层的混凝土网格剪力墙住宅建筑的要求,研发了网格尺寸为400mm×400mm的大网格剪力墙承重体系.通过2个剪跨比为2.02和2个剪跨比为1.13的大网格剪力墙试件的拟静力试验,研究大网格剪力墙的破坏形态、滞回特性、变形能力和承载能力等.试验结果表明:试件横肢两端-竖向裂缝贯通肢高;竖肢水平开裂,端竖肢底部...     

Nonlinear seismic assessment of irregular coupled wall systems using high‐performance fiber‐reinforced cement composites

Reinforced concrete coupled wall systems that consist of multiple shear walls linked by coupling beams are known to be very effective for resisting lateral loads in high‐rise buildings. As to improving the seismic capacity of coupled wall systems, high‐performance fiber‐reinforced cement composites (HPFRCCs) have been recently considered. These materials are characterized by tension strain‐hardening behavior that can improve the ductility and toughness of structures subjected to reversed cyclic loading. In this study, nonlinear finite element analyses were conducted to investigate the effects of HPFRCCs on the seismic behavior of irregular tall buildings with coupled wall systems. The coupling beams were modeled using moment hinge elements, and the structural walls were modeled using fiber elements. Comparisons between analysis and test results of coupled wall specimens with and without HPFRCCs indicate that the modeling methods used well predict both the overall and local behaviors. The responses of a 56‐story irregular tall building with coupled walls are discussed with focus on the effects of HPFRCCs. It is noted that the use of HPFRCCs in coupling beams and structural walls of one‐fourth height from the base greatly affects the failure mode. For irregular tall buildings, nonlinear response history analysis indicates higher mode effects are critical.     

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。     

高强混凝土钢板组合剪力墙压弯性能试验研究

通过对9片不同形式的高轴压比高强混凝土组合剪力墙试件进行低周往复拟静力试验,研究钢筋混凝土剪力墙、两端暗柱设置型钢剪力墙和中部内藏钢板剪力墙等形式试件在压弯状态下的破坏机理、滞回特性、承载力特性以及变形能力等。试验结果表明,钢板的加入可以大幅提高剪力墙试件的抗弯承载力,当设计轴压比小于0.5时,高强混凝土钢板组合剪力墙的变形能力可以满足设计要求,当设计轴压比超过0.5时,高强混凝土钢板组合剪力墙试件在受弯状态下的变形能力较弱。根据试验结果,提出了高强混凝土钢板组合剪力墙抗弯承载力计算的建议公式。     

Responses of single and group piles within MSE walls under static and cyclic lateral loads

To investigate the behavior of piles and the performance of the mechanically stabilized earth (MSE) walls under static and cyclic lateral loading, six reduced-scale model tests of single and group piles within the MSE walls were conducted inside a test box. In the single pile tests, a hollow aluminum tube as a pile was placed at a distance of 2D or 4D (D is pile diameter) behind the wall facing, while in the group pile tests, the piles were only placed at the distance of 2D with a spacing of 3.3D between the piles. The piles were subjected to static lateral loading only and cyclic lateral loading followed by static loading until failure. The test results showed that the lateral load capacity of each pile in the group pile test was approximately 60% that of the single pile, while the wall facing displacements and the geogrid strains in the group pile test were larger than those in the single pile test. The lateral pile capacity, the wall facing displacement, the strain in the geogrid, and the lateral earth pressure behind the wall facing in the static and cyclic loading tests were evaluated at the pile head displacement equal to 20%D.     

Behavior of fully grouted reinforced concrete masonry shear walls failing in flexure: Analysis

This paper contains analysis details of an experimental study conducted to evaluate the ductility and energy dissipation characteristics of reinforced concrete masonry shear walls failing in flexure. The test program consisted of six reinforced concrete masonry shear walls tested under reversed cyclic lateral displacements simulating seismic loading effects. This paper focuses on documenting the levels of ductility attained by the walls and evaluating the contribution of flexure and shear deformations to the overall wall lateral displacement. Analysis of the measured displacements showed that the contribution of shear displacement to the overall wall displacement was significant (up to 28% of total displacement at maximum load) but was not the same for all the walls having height-to-length ratio of 2.0. Displacement ductility values up to 4.5 and 11.4 were measured corresponding to maximum load and 20% strength degradation, respectively. Values up to 3.5 were calculated for the ductility-related seismic response modification factor for the test walls corresponding to design drift levels of 1%. The relationship between the energy dissipation and the ratio of the post-yield to the yield displacement was found to be almost linear for the test walls. In addition, the wall stiffnesses degrade rapidly to about 50% of their initial stiffness at very low drift levels (0.1% drift); however, the test walls maintained at least 80% of their maximum strength up to large displacements (2.2% drift).