Experimental and analytical study on seismic behavior of steel-concrete multienergy dissipation composite shear walls

In this paper, a steel-concrete multi-energy dissipation composite shear wall, comprised of steel-reinforced concrete （SRC） columns, steel plate （SP） deep beams, a concrete wall and energy dissipation strips, is proposed. In order to study the multi-energy dissipation behavior and restorability after an earthquake, two stages of low cyclic loading tests were carded out on ten test specimens. In the first stage, test on five specimens with different number of SP deep beams was carried out, and the test lasted until the displacement drift reached 2%. In the second stage, thin SPs were welded to both sides of the five specimens tested in the first stage, and the same test was carried out on the repaired specimens （designated as new specimens）. The load-bearing capacity, stiffness, ductility, hysteretic behavior and failure characteristics were analyzed for both stages and the results are discussed herein. Extrapolating from these results, strength calculation models and formulas are proposed herein and simulations using ABAQUS carried out, they show good agreement with the test results. The study demonstrates that SRC columns, SP deep beams, concrete wall and energy dissipation strips cooperate well and play an important role in energy dissipation. In addition, this study shows that the shear wall has good recoverability after an earthquake, and that the welding of thin SP＇s to repair a deformed wall is a practicable technique.

Research on seismic performance of shear walls with concrete filled steel tube columns and concealed steel trusses

In order to further improve the seismic performance of RC shear walls, a new composite shear wall with concrete filled steel tube （CFT） columns and concealed steel trusses is proposed. This new shear wall is a double composite shear wall; the first composite being the use of three different force systems, CFT, steel truss and shear wall, and the second the use of two different materials, steel and concrete. Three 1/5 scaled experimental specimens： a traditional RC shear wall, a shear wall with CFT columns, and a shear wall with CFT columns and concealed steel trusses, were tested under cyclic loading and the seismic performance indices of the shear walls were comparatively analyzed. Based on the data from these experiments, a thorough elastic-plastic finite element analysis and parametric analysis of the new shear walls were carried out using ABAQUS software. The finite element results of deformation, stress distribution, and the evolution of cracks in each phase were compared with the experimental results and showed good agreement. A mechanical model was also established for calculating the load-carrying capacity of the new composite shear walls. The results show that this new type of shear wall has improved seismic performance over the other two types of shear wails tested.

Elasto-plastic Analysis of High-strength Concrete Shear Wall with Boundary Columns Using Fiber Model

In this study,an experimental study and numerical calculations using fiber model were conducted for four high-strength concrete shear walls with boundary columns under low cyclic load.The boundary column and shear wall were divided into fiber elements,and PERFORM-3D finite element analysis software was used to carry out push-over analysis on the test specimens.The results show that the finite element analysis results were in good agreement with the experimental results.The proposed analysis method could perform elasto-plastic analysis on the high-strength concrete shear wall with boundary columns without distinguishing the categories of frame column and shear wall.The seismic performance of high-strength concrete shear wall with boundary columns was analyzed using the following parameters:axis compression ratio,height to width ratio,ratio of vertical reinforcement,and ratio of longitudinal reinforcement in the boundary column.The results show that the increase in the axial compression ratio causes the bearing capacity of the shear wall to increase at first and then to decrease and causes the ductility to decrease.The increase in the height to width ratio causes the bearing capacity of the shear wall to decrease and its ductility to increase.The ratio of vertical reinforcement was found to have little effect on the bearing capacity and ductility.The increase in the ratio of longitudinal reinforcement in boundary column resulted in a significant increase in the bearing capacity and caused the ductility to decrease at first and then to slowly increase.

Analysis and seismic tests of composite shear walls with CFST columns and steel plate deep beams

A composite shear wall concept based on concrete filled steel tube （CFST） columns and steel plate （SP） deep beams is proposed and examined in this study. The new wall is composed of three different energy dissipation elements： CFST columns; SP deep beams; and reinforced concrete （RC） strips. The RC strips are intended to allow the core structural elements - the CFST columns and SP deep beams - to work as a single structure to consume energy. Six specimens of different configurations were tested under cyclic loading. The resulting data are analyzed herein. In addition, numerical simulations of the stress and damage processes for each specimen were carried out, and simulations were completed for a range of location and span-height ratio variations for the SP beams. The simulations show good agreement with the test results. The core structure exhibits a ductile yielding mechanism characteristic of strong column-weak beam structures, hysteretic curves are plump and the composite shear wall exhibits several seismic defense lines. The deformation of the shear wall specimens with encased CFST column and SP deep beam design appears to be closer to that of entire shear walls. Establishing optimal design parameters for the configuration of SP deep beams is pivotal to the best seismic behavior of the wall. The new composite shear wall is therefore suitable for use in the seismic design of building structures.

Structural Analysis of a RC Shear Wall by Use of a Truss Model

Purpose of present work is to develop a reliable and simple method for structural analysis of RC Shear Walls. The shear wall is simulated by a truss model as the bar of a truss is the simplest finite element. An iterative method is used. Initially, there are only concrete bars. Repeated structural analyses are performed. After each structural analysis, every concrete bar exceeding tensile strength is replaced by a steel bar. For every concrete bar exceeding compressive strength, first its section area is increased. If this is not enough, a steel bar is placed at the side of it. For every steel bar exceeding tensile or compressive strength, its section area is increased. After the end of every structural analysis, if all concrete and steel bars fall within tensile and compressive strengths, the output data are written and the analysis is terminated. Otherwise, the structural analysis is repeated. As all the necessary conditions (static, elastic, linearized geometric) are satisfied and the stresses of ALL concrete and steel bars fall within the tensile and compressive strengths, the results are acceptable. Usually, the proposed method exhibits a fast convergence in 4 - 5 repeats of structural analysis of the RC Shear Wall.

焊接多腔双钢板-混凝土组合剪力墙抗震性能分析

大多数双钢板-混凝土组合剪力墙采用螺栓连接或焊接肋的方式使钢板和混凝土协同工作。然而,这种连接方式可能导致整体性和塑性变形效率较低,且制作复杂,焊接多腔双钢板-混凝土组合剪力墙能够有效地避免这些问题。为了深入研究焊接多腔双钢板-混凝土组合剪力墙的抗震性能,基于约束混凝土真三轴塑性-损伤本构模型和钢材弹塑性混合强化-韧性损伤本构模型,建立了组合剪力墙的精细化三维实体-壳模型,将模拟所得的滞回曲线、骨架曲线、刚度退化曲线、弹性刚度、承载力、累积耗能、等效阻尼粘滞系数和延性系数与已有拟静力试验结果相比较,发现两者吻合较好。分析结果表明:轴压比对组合剪力墙模型算例刚度和承载力的影响较小,而随剪跨比增大,组合剪力墙模型算例的刚度和承载力呈线性降低;轴压比对组合剪力墙模型算例总塑性耗能的影响较小,而剪跨比的影响较大,剪力墙总塑性耗能随剪跨比增大而降低;轴压比和剪跨比都不会改变算例各部件的耗能分配机制,即组合剪力墙模型算例以外钢板和内隔板耗能为主。

装配式轻钢框架-轻钢骨架轻混凝土墙板结构抗震性能

为研究装配式轻钢框架-轻钢骨架轻混凝土墙板结构抗震性能,对1个足尺轻钢框架结构试件和3个足尺轻钢框架-轻钢骨架轻混凝土墙板结构试件进行了低周反复荷载下的抗震性能试验及理论分析,试件变量包括:2种装配构造,即内嵌式装配墙板、外贴式装配墙板;2种轻钢骨架轻混凝土墙板,即框架式轻钢骨架轻混凝土墙板、桁架式轻钢骨架轻混凝土墙板。研究了各试件的破坏特征和损伤演化过程,分析了结构滞回特性、承载力、变形能力、刚度退化、耗能性能和应变。结果表明:装配式轻钢框架-轻钢骨架轻混凝土墙板结构共同工作性能良好,其水平承载力相比轻钢框架提高了204.7%~210.4%,抗侧刚度提高了257.3%~512.5%,结构变形及耗能能力有显著提高;内嵌墙板的自攻钉连接构造以及外贴墙板的螺栓连接构造传力性能可靠,结构具备2道抗震防线的受力特征;基于简化塑性分析模型以及拉压杆软化桁架模型,对试件承载力进行了计算,计算结果与试验符合较好。

钢管混凝土键连接框架梁和剪力墙的受剪性能

目的 研究钢管混凝土键连接框架梁和剪力墙的受剪性能,为工程应用提供设计依据。方法 应用有限元分析软件ABAQUS对比钢管混凝土键连接与现浇连接梁墙的结构受剪性能,分析前者受剪机理及不同因素对受剪性能的影响。结果 钢管混凝土键连接梁墙的结构承载力和延性系数较现浇结构分别提高约10%和34%;钢材强度从Q235到Q390,初始刚度增加8.44%;截面高度从100 mm到120 mm,延性系数提高17.73%;截面厚度每增加2 mm,承载力提高约15%;截面长度和混凝土强度等级对承载力、初始刚度和延性系数的影响均小于15%,纵向距离对其受剪性能几乎无影响。结论 采用钢管混凝土键连接梁墙的结构总体受剪性能优于现浇结构;钢材强度和截面厚度分别是影响初始刚度和承载力的主要因素。

HPC端部加强双钢板组合剪力墙的抗震性能

为研究高性能混凝土端部加强双钢板组合剪力墙受力机理及破坏形态,以轴压比、腹部普通混凝土强度等级为关键参数,设计了4片普通试件,7片HPC端部加强试件,运用ABAQUS构建其有限元模型,研究其抗震性能。结果表明:同轴压比下,HPC端部加强试件相比普通试件屈服荷载提高16.30%,峰值荷载提升13.40%;随着轴压比提高,HPC端部加强试件峰值荷载和屈服荷载分别提高7.22%和2.72%,随着轴压比减小,HPC端部加强试件延性提升22.26%;提高腹部腔体混凝土强度等级,HPC端部加强试件的屈服荷载和峰值荷载分别提高13.01%和11.14%,延性提升16.91%。

十字形钢管束自密实混凝土短肢剪力墙轴压性能研究

为研究十字形钢管束自密实混凝土短肢剪力墙的轴压受力性能,通过模型试验研究和ABAQUS数值模拟相结合的方法,对不同腔体数十字形钢管束自密实混凝土短肢剪力墙的轴压性能进行分析。首先,根据轴压试验结果对剪力墙的破坏形态和轴向荷载-应变曲线等轴压受力性能进行分析,提出轴压承载力计算公式。其次,建立剪力墙轴压有限元计算模型,将试验结果和模型计算结果进行对比以验证有限元模型的准确性。最后,根据有限元参数化分析结果验证并修正剪力墙轴压承载力计算公式。研究发现,剪力墙的轴向荷载-应变曲线在不同腔体数下具有相似的特征,表明其变形能力良好。在破坏过程中,钢管束对核心混凝土的约束作用显著,提高了试件的延性和承载能力,其中钢管束的破坏主要表现为多波鼓曲和焊缝开裂,尤其是在钢管束中部的1/4区域。此外,随着腔体数增加,剪力墙极限承载力提升,但其延性系数有所下降。本研究提出的简化公式与有限元分析结果的误差控制在10%以内,该公式可为工程设计应用提供理论借鉴。

绿色纤维局部增强装配整体式混凝土剪力墙数值模拟分析

为了提高装配整体式混凝土剪力墙的抗震性能,响应“绿色低碳”政策的号召,基于装配整体式混凝土剪力墙模型的数值模拟,对比试验数据,验证了数值模拟的合理性,研究了在低周反复荷载作用下,绿色纤维(从废旧轮胎中提取的回收钢纤维制备而成的绿色纤维)体积率对装配整体式混凝土剪力墙的承载能力、延性性能和耗能性能的影响,计算出各模型的位移延性系数和耗能系数。模拟结果表明,绿色纤维能够明显改善装配整体式混凝土剪力墙的抗震性能,绿色纤维的加入使模型的滞回曲线更加饱满,滞回环的面积更大。随着绿色纤维体积率的增大,模型的承载能力、延性性能和耗能性能也逐渐增大,当绿色纤维体积率达到1.5%时,模型的承载能力、延性性能和耗能性能提升最为明显。

新型横向连接装配整体式榫卯剪力墙结构抗震性能模拟分析

为加强装配整体式剪力墙的竖向接缝性能和墙体的整体性,在传统榫卯接缝的基础上,研究提出一种采用新型横向连接的装配式榫卯剪力墙,设置横向凹槽处的封闭环形钢筋闭合连接,并与纵向孔洞处的竖向钢筋绑扎形成钢筋骨架,以提高剪力墙的整体稳定性。设置1组现浇剪力墙、1组传统装配式榫卯连接装配式剪力墙、1组采用新型横向连接的装配式榫卯剪力墙,使用ABAQUS有限元软件模拟在低周往复荷载作用下不同墙体的受力情况及破坏过程,并且对比分析不同竖向接缝对剪力墙工作性能和抗震能力的影响。研究结果表明,采用新型榫卯横向连接的装配式榫卯剪力墙的刚度和承载能力与现浇剪力墙基本一致,能够满足“等同现浇”的要求。

型钢混合连接装配式混凝土剪力墙结构受力机理研究

结合钢筋混凝土结构和钢结构的优势,设计一种型钢-螺栓-后浇混凝土装配式剪力墙型钢混合连接。基于ABAQUS有限元软件建立混合连接的剪力墙模型,探究低周往复荷载作用下该混合连接预制剪力墙的受力性能,主要分析模型的破坏形态、受力机制、变形曲线、特征承载力等,并扩展分析了材料强度、轴压比、连接件数量、型钢截面高度等参数对模型受力性能影响。结果表明:装配式剪力墙破坏形态为压弯破坏,破坏时钢连接件仍保持完整,符合“强连接,弱墙肢”的基本设计理念;装配式剪力墙具有较好的承载力、延性和刚度;轴压比对结构承载力影响显著,型钢混合连接间距的增大能有效提升剪力墙延性。建立了型钢混合连接抗剪需求承载力计算模型和公式,并与国内外规范计算值对比分析,公式计算值和BS EN 1992欧洲规范计算值分别与模拟值的误差在15%和20%以内,均可用于型钢混合连接剪力墙竖缝受剪承载力设计参考。

钢板混凝土剪力墙拉弯剪性能试验研究

超高层建筑“细柔”特征容易引起底部剪力墙在强震下处于拉-弯-剪复合受力状态,中国《超限高层建筑工程抗震设防专项审查技术要点》(建质[2015]67号)建议墙肢采用配置型钢/钢板的方式来改善该种抗震性能,但缺乏相关试验研究。为此,进行了6片钢板混凝土剪力墙的低周往复荷载试验,研究了轴拉比、含钢率及剪跨比对墙肢拉弯剪性能的影响。研究表明:拉弯剪作用引起钢板混凝土剪力墙密集的裂缝分布和显著的钢材强化,并导致其剪切-拉弯耦合破坏。轴拉比增大,墙肢承载力、初始抗侧刚度和延性分别降低22%、41%和39%;剪跨比减小,墙肢承载力和抗侧刚度至少提升23%;同时增大含钢率和降低剪跨比,墙肢延性提高10%。相比其他国家规范,中国规范对拉弯剪作用下钢板混凝土剪力墙的抗剪承载力预测效果更好,但其未能考虑高含钢率对裂面销栓力的影响,故建议采用暗柱的初始含钢率进行修正。

边缘配置高强纵筋的高强再生混凝土剪力墙抗震性能试验研究

为研究不同剪跨比、不同边缘构造形式对边缘配置高强纵筋的高强再生混凝土剪力墙抗震性能的影响规律,进行了3个C50再生混凝土剪力墙低周往复荷载试验,包括1个现浇高剪力墙、1个现浇中高剪力墙、1个装配式中高剪力墙。分析了各试件的破坏形态、滞回性能、承载力、延性、刚度退化、耗能能力。结果表明:边缘配置高强纵筋的高强再生混凝土剪力墙破坏形态均以弯曲破坏为主,各试件滞回曲线较饱满,耗能能力较好;中高剪力墙的承载力和刚度比高剪力墙明显提高,但延性系数降低;装配式再生混凝土中高剪力墙在达到峰值荷载之前整体性良好,但由于后浇结合面相对薄弱,试件破坏相对较早,承载力下降较快,延性稍差。基于试验结果,建立了边缘配置高强纵筋的高强再生混凝土中高及高剪力墙承载力计算公式,计算结果与试验结果吻合较好。

十字形钢管束高强混凝土组合剪力墙的抗剪承载力研究

为研究不同参数对十字形钢管束高强混凝土组合剪力墙抗剪承载力的影响,通过ABAQUS有限元软件建立了十字形钢管束高强混凝土组合剪力墙的有限元模型,重点考察钢材强度、混凝土强度、钢板厚度、钢管厚度、轴压比、墙体长度、墙体高度、腔体长度等参数对此类组合剪力墙抗剪承载力的影响。分析结果表明:随着钢材强度、钢板厚度、钢管厚度、墙体长度的增加和墙体高度的减小,试件的抗剪承载力呈显著增大趋势;随着混凝土强度的提高和腔体长度的减小,试件的抗剪承载力略呈增大趋势;当轴压比较小时(n∈(0,0.3]),轴压比对试件的抗剪承载力有一定的提高作用;当轴压比较大时(n∈(0.3,0.8]),随着轴压比的增加其抗剪承载力逐渐降低。最后,提出了十字形钢管束高强混凝土组合剪力墙的抗剪承载力计算公式。

钢板-混凝土组合剪力墙裂缝控制及监测分析

以实际工程为背景,对1.7 m厚钢板-混凝土组合剪力墙的裂缝控制及监测进行分析。大体积混凝土构件,由于其水化热比较高容易产生温度裂缝,基于此首先对原材料及配合比进行优化设计,降低混凝土水化热。然后对大厚度组合剪力墙浇筑后采取合理的养护措施控制其内部温度以及对裂缝发生情况进行实测分析,最后经过一系列针对性的裂缝控制措施及监测结果表明,采用优化设计对大厚度组合剪力墙的裂缝控制优于同类工程的裂缝控制效果。

预制轻钢轻混凝土剪力墙-楼板连接部抗剪性能试验研究

提出一种装配式轻钢轻混凝土剪力墙与混凝土楼板的装配连接方式,为研究该连接节点的抗剪性能,开展了4个墙体-楼板连接试件的低周往复加载试验,分析了连接节点的滞回性能、刚度退化、延性、耗能能力及承载力性能。结果表明:不同连接构造形式对墙体-楼板连接节点的承载力影响显著,抗剪螺栓能有效提高节点的刚度与水平抗剪承载力;承载力分析结果显示,设有抗剪螺栓的连接节点承载力比预制墙体抗剪承载力高了34.3%,满足节点承载力要求,最后给出了装配式轻钢轻混凝土墙-楼板连接节点设计建议。

装配式部分包覆钢-混凝土组合剪力墙受弯承载力计算

为研究装配式部分包覆钢-混凝土组合短肢剪力墙的受弯承载力和抗震性能,设计制作了5片短肢剪力墙。通过拟静力试验,分析轴压比、翼缘板厚度、混凝土强度和型钢强度对试件破坏形态、滞回性能、受弯承载力、变形能力、刚度退化和耗能能力的影响。试验结果表明:短肢剪力墙表现为典型的压弯破坏;轴压比由0.4增大至0.6,试件的承载力及延性均降低;翼缘板厚度的变化对试件的承载力和延性影响较小;随着混凝土和型钢强度的增大,试件的承载力随之增大;罕见地震作用下,试件表现出良好的抗震性能,提出部分包覆钢-混凝土组合剪力墙受弯承载力计算公式,计算结果与试验值吻合度较高。

钢框架+钢管混凝土束剪力墙结构装配式施工研究

以某市场升级改造工程为实例进行分析,研究钢框架和钢管混凝土束剪力墙结构体系在装配式施工中的应用。该工程采用了多层结构,其中地上主体结构采用了创新的钢框架和钢管混凝土束剪力墙结构,并详细探讨了该结构体系的结构优势以及装配率的计算方法。研究表明,钢管混凝土束组合结构住宅体系具有抗震性能好、施工周期缩短、工业化生产、现场装配化施工、节能环保等优点,对提高建筑工程的质量和效率具有重要意义。