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.

Experimental Study on Improving Seismic Behavior of Load-Bearing Masonry Wall Made of Autoclaved Aerated Concrete

To investigate the seismic behavior of autoclaved aerated concrete load-bearing masonry wall(AACLMW), a piece of control block wall without constructional measures and five pieces of block walls with different constructional measures were tested under low reversed cyclic loading which imitated low to moderate earthquake force. The seismic behavior of AACLMW with different constructional measures in terms of failure mode, hysteretic curve, deformation capacity and displacement ductility was studied and compared with that without constructional measures. The experimental results indicate that the constructional measures comprising constructional columns and horizontal concrete strips are effective for improving the seismic behavior of AACLMW. The study in this paper can provide a reliable experimental basis for further analysis and engineering application of AACLMW in the future.

Effects of timber infill walls on the seismic behavior of traditional Chinese timber frames

This study investigates the enhanced effect of timber infill walls on the seismic behavior of traditional Chinese timber frames.Two 1/2 scaled traditional Chinese timber infill walls(TIWs),two 1/2 scaled timber frames with timber infill walls(TFTIWs)and one 1/2 scaled timber frame(TF)were fabricated and tested under low-cyclic reversed loading.The failure modes,strength,stiffness,and energy consumption capacity of the TIWs and the TFTIWs were obtained,and the effects of the TIWs on the seismic performance of the TFTIWs were investigated.The results showed that the TIWs can increase the stiffness and ultimate bearing capacity of the TF,up to 60%and 80%,respectively.The strength degradation coefficient of the TFTIWs was slightly higher than that of the TF when the inter-story drift ratio exceeded 0.02 rad,and the TIWs helped to mitigate the strength degradation of the TFTIWs.It was also found that the TFTIWs had a higher cumulative energy dissipation when compared with the TF(up to a 60%increase),indicating the TIWs had reasonably good energy dissipation capacity.When the TIWs generated a solid contribution to the carrying capacity and energy dissipation of the TF,the lateral drift thresholds were 1/100 and 1/43 of the column height,respectively.Furthermore,the TIWs and TFTIWs presented a good ductility,and the TIW could effectively reduce the pull-out amount of the tenon from the mortise of the TF;however,the TIWs had little influence on the stiffness degradation level or improvement of the ductility of the TF.

Seismic behavior and mechanism analysis of innovative precast shear wall involving vertical joints

To study the seismic performance and load-transferring mechanism of an innovative precast shear wall(IPSW) involving vertical joints, an experimental investigation and theoretical analysis were successively conducted on two test walls. The test results confirm the feasibility of the novel joints as well as the favorable seismic performance of the walls, even though certain optimization measures should be taken to improve the ductility. The load-transferring mechanism subsequently is theoretically investigated based on the experimental study. The theoretical results show the load-transferring route of the novel joints is concise and definite. During the elastic stage, the vertical shear stress in the connecting steel frame(CSF) distributes uniformly; and each high-strength bolt(HSB)primarily delivers vertical shear force. However, the stress in the CSF redistributes when the walls develop into the elastic-plastic stage. At the ultimate state, the vertical shear stress and horizontal normal stress in the CSF distribute linearly; and the HSBs at both ends of the CSF transfer the maximum shear forces.

Experimental research on the seismic behavior of CSPSWs connected to frame beams

The seismic performance of composite steel plate shear walls （CSPSWs） that consist of a steel plate shear wall （SPSW） with reinforced concrete （RC） panels attached to one or both sides by means of bolts or connectors is experimentally studied. The shear wall is connected to the frame beams but not to the columns. This arrangement restrains the possible out-of-plane buckling of the thin-walled steel plate, thus significantly increasing the bearing capacity and ductility of the overall wall, and prevents the premature overall or local buckling failure of the frame columns. From a practical viewpoint, these solutions can provide open space in a floor as this type of composite shear walls with a relatively small aspect ratio can be placed parallel along a bay. In this study, four CSPSWs and one SPSW were tested and the results showed that both CSPSWs and SPSW possessed good ductility. For SPSW alone, the buckling appeared and resulted in a decrease of bearing capacity and energy dissipation capacity. In addition, welding stiffeners at corners were shown to be an effective way to increase the energy dissipation capacity of CSPSWs.

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。

装配式轻钢框架-短肢组合墙结构抗震性能研究

为研究装配式轻钢框架-短肢组合墙结构的抗震性能,对3个足尺试件(1个轻钢框架结构、1个轻钢框架-短肢桁架结构、1个轻钢框架-短肢桁架组合墙结构)进行了低周反复荷载试验。分析了结构破坏模式、滞回曲线、承载力、刚度退化、变形性能、耗能和应变。结果表明:短肢桁架以及短肢桁架组合墙作为结构第一道抗震防线,高效提升了轻钢框架结构的抗震性能;相对于轻钢框架结构试件,轻钢框架-短肢桁架组合墙结构试件的极限承载力提高了28482%,初始刚度提高了24446%;组合墙内的短肢钢桁架与混凝土的共同工作性能良好,混凝土的约束作用抑制了短肢桁架的屈曲失稳,短肢桁架提高了组合墙核心混凝土的变形能力。所提出的装配式轻钢框架-短肢组合墙结构传力路径明确、抗震性能优越、装配便捷,特别适用于低、多层装配式轻钢组合结构,其设计思路同样可用于其他装配式钢框架结构。

不同填充墙构造方法对RC框架抗震性能影响研究

为定量评估不同填充墙构造方法对钢筋混凝土(reinforced concrete,RC)框架抗震性能的影响,搜集整理国内外砌体填充墙RC框架拟静力试验数据,筛选出19篇文献中共68个数据较为详尽的试件作为样本,分析对比柔性连接填充墙、增强填充墙整体性及设置阻尼耗能装置三类构造方法对试件的峰值点承载力、初始刚度、位移延性系数和等效黏滞阻尼系数4个参数的影响程度。结果表明:相较于传统构造方法,柔性连接填充墙框架的承载力和刚度均有所下降,变形能力提升;增强整体性的方法可提升试件承载力、刚度和变形能力,可作为一种较好的既有框架结构的加固方法;设置阻尼耗能装置虽然结构的承载力和刚度有所降低,但提升了结构的变形能力和耗能能力,在建造成本可接受的情况下可作为新建建筑的韧性提升方案。

Seismic behavior of precast concrete coupled shear walls with engineered cementitious composite (ECC) in the critical cast-in-place regions

The seismic performance of precast reinforced concrete （RC） coupled shear walls is significantly influenced by coupling beams and the beam-to-wall joints during large deformations into plastic ranges. This study investigated the use of engineered cementitious composite （ECC） in the cast-in-place beam-to-wall joints and the upper regions of the composite coupling beams as an innovative method to improve the seismic performance ofprecast RQ coupled shear walls. Two 1/2-scale precast coupled shear walls were tested under reversed cyclic loading and seismic behavior in terms of failure characteristic, mechanical characteristic value, load-displacement hysteresis curves, load-displacement envelope relationship, stiffness degradation, ductility and energy dissipation capacity were evaluated. Research results show that the substitution of concrete with ECC in the critical cast-in-place regions proved to be an effective method to improve the seismic performance of the two-story spatial of precast RC coupled shear walls.

采用自复位U形连接件的装配式钢框架-复合墙结构性能研究

对于内填RC墙的框架结构,为有效减小结构的损伤,改善结构力学性能,本文研究了一种在框架与墙之间设置开缝并安装耗能连接件,能够耗散能量从而有效地保护主体结构。采用ABAQUS分析了不同类型耗能连接件的内力特性以及节点的受力破坏模式。通过在两侧开缝的密肋复合墙-钢框架结构中设置可滑移连接,实现了节点的耗能作用。研究结构表明:U形连接件水平段长度对连接件极限位移影响较大,可以通过双折线理想弹塑性荷载-位移曲线描述U形连接件在竖向压力与水平剪切作用下的荷载-位移关系。采用耗能连接件的结构在加载前期残余变形小,具有一定的自复位能力,并且能满足结构的大变形要求。通过以上分析,本文基于承载能力极限状态提出了耗能连接件的设计公式。

带新型复合轻质墙体的框架结构抗震性能试验

为研究某种新型装配式复合轻质墙体的抗震性能及对框架结构抗震性能的影响,通过设计制作3榀1∶2缩尺的新型复合轻质墙体框架-试件进行拟静力试验,以界面仓的注仓砂浆强度为试验参数,对结构的破坏模式、滞回曲线、骨架曲线、刚度退化、累计耗能及装配连接部位变形情况进行分析。结果表明:1)界面砂浆层的黏结使得加载后框架和轻质墙体能协同作用,加载初期框架柱和墙有相同的变形趋势;2)当加载位移角增大到1%时,交界面开裂,当位移角增大至2%时,梁柱和墙完全脱开;3)在层间位移角范围为2%~4%时的大变形阶段,轻质墙体和框架结构均产生破坏,但墙体与框架的锚钉连接未失效,墙体未发生脱落,框架承载力下降缓慢;4)砂浆强度对连接性能的影响不明显,采用M3.5砂浆注浆强度能使得复合轻质墙体连接于框架时具有适宜的刚度。

新型竖缝互锁灌孔复合砌块墙体抗压及抗震性能试验研究

新型竖缝互锁灌孔复合砌块墙体是一种绿色、环保且低碳的新型砌体结构,为研究其抗压性能与抗震性能,分别对墙体进行轴压试验与拟静力试验,分析灌孔方式与构造柱类型对该墙体抗压承载力、荷载分配与变形协调等方面的影响,以及不同构造柱类型对墙体抗震性能的影响。结果表明,随着现浇构造柱与复合砌体部分强度差的减小,墙体整体变形协调能力有所提升;提出了适用于设置构造柱的新型墙体的抗压承载力计算公式,计算值与试验值吻合度较好;芯柱构造柱对墙体延性的提升效率高于现浇构造柱墙体,而现浇构造柱墙体的抗震承载力、极限位移等指标优于芯柱构造柱墙体。研发绿色、环保、低碳的新型砌体结构是助力国家乡村振兴战略和改善村镇建筑抗灾能力的有效途径,该新型墙体结构为新疆地区村镇建筑提供了一种新的选择。

爆炸荷载作用下砌体填充墙对RC框架结构损伤破坏的影响

砌体填充墙作为非结构构件在建筑结构抗爆分析中常被忽略,而实际爆炸事故中填充墙多发生严重破坏,从而影响爆炸波的传播及其与结构的相互作用以及结构的损伤破坏等级。基于精细化数值仿真方法评估外部爆炸作用下砌体填充墙对钢筋混凝土(reinforced concrete,RC)框架结构损伤破坏的影响。首先,采用LS-DYNA有限元分析软件分别对典型砌体填充墙和含填充墙RC框架的近区爆炸试验进行复现,验证所采用的填充墙简化微观建模方法、材料本构模型和参数,以及任意拉格朗日欧拉爆炸荷载施加方法和爆炸波-结构流固耦合算法的适用性。进一步结合结构混合单元建模方法,开展了美国联邦应急管理署规定的普通轿车炸弹(454 kg TNT当量)在底层边柱位置爆炸下,6度、7度和8度抗震设防烈度的典型6层纯框架和含填充墙框架结构动力行为的数值仿真分析,考察了爆炸波传播路径,以及结构的动态响应、损伤破坏和抗倒塌机制。结果表明:该工况中填充墙能够有效阻挡爆炸波的传播,作用于目标柱相邻内柱上的超压峰值降低95%,减轻了内部构件的损伤程度;但同时加剧了结构迎爆面的损伤破坏,如3种抗震设防烈度的含填充墙框架目标柱柱中侧向位移较纯框架分别增加21.4%、31.1%和14.8%;不同抗震设防烈度的纯框架和含填充墙框架的顶层目标柱竖向位移基本相同,即抗震设防烈度及砌体填充墙对框架结构整体倒塌行为的影响可以忽略。

考虑填充墙作用的钢筋混凝土框架结构抗震性能研究

通过纯框架结构模型和半高填充墙框架结构模型拟静力试验,研究半高填充墙对框架柱破坏模式的影响。基于试验结果建立了钢筋混凝土框架结构抗震分析模型并开展参数化研究,分析了砌筑材料、墙体高度对结构抗震性能的影响。结果表明:填充墙的存在提高了结构的承载能力和刚度,但降低了结构的延性;随着墙体砌筑高度增加,混凝土柱自由高度降低,墙柱高度比为0.2时,砌体墙对框架结构的抗震性能影响不显著,当墙柱高度比达到0.6时,柱子破坏模式由弯曲破坏转变为剪切破坏;砌筑材料在墙柱高度比在0.4及以下时,对结构抗震性能影响的差异不显著,墙柱高度比在0.6及以上时对抗震性能影响的差异逐渐显现;相同砌筑高度下加气混凝土砌块填充墙对钢筋混凝土框架结构抗震性能影响最小,因此,在不采取其他改良措施的情况下,建议采用加气类混凝土砌块来降低填充墙对钢筋混凝土框架结构抗震性能的不利影响。

装配式轻钢框架-复合轻墙结构抗震性能试验研究

文中主要针对低周反复荷载作用下装配式轻钢框架-复合轻墙结构的力学特性进行了分析,并与常规轻型钢框架进力学特性进行了对比,深入探析粉煤灰层厚度对装配式轻钢框架-复合轻墙结构的抗震性能的影响。结果表明,与轻型钢框架相比,装配式轻钢框架-复合轻墙结构的破坏荷载提升85.5%,破坏刚度提升18.5%,累计耗散能提升83.2%;填充粉煤灰后,装配式轻钢框架-复合轻墙结构的破坏荷载18.5%,破坏刚度变化不大,累计耗散能提升28.6%。总体上,填充粉煤灰可增强装配式轻钢框架-复合轻墙结构的抗震性能。

装配式钢框架-内填轻钢复合墙板结构抗震性能试验研究

为适应多高层装配式住宅结构的发展需求,提出了一种新型装配式钢框架-内填轻钢复合墙板结构体系。对4个足尺钢框架-轻钢复合墙板试件进行了低周往复加载试验研究,分析了填料强度、龙骨规格、墙板开洞等因素对试件破坏模式、滞回性能、抗剪承载力、抗侧刚度、延性及耗能性能的影响,并对钢框架与轻钢复合墙板协同受力机制进行了分析。结果表明:钢框架与内填墙板协同工作性能良好;结构中墙板为剪切型破坏,最终以填料角部受压破坏、骨架与填料间黏结滑移失效、墙面板破坏及螺钉连接失效为主要破坏特征,钢框架未发生明显破坏,并对内填墙板具有良好约束作用;填料强度提高及立柱截面增大可提高结构的抗剪承载力、刚度及耗能性能,但延性降低;开设洞口使得墙板的抗剪承载力、初始刚度以及耗能性能均降低,但延性增大。加载初期,内填墙板承担约85%的水平荷载,加载后期,墙板逐渐退出工作,钢框架承担主要水平荷载和倾覆弯矩。

装配式轻钢框架–钢丝网架珍珠岩复合墙板结构振动台试验

为发展高效抗震、绿色节能、施工便捷的装配式村镇住宅建筑,提出了一种适于村镇低层住宅的低能耗装配式轻钢框架–钢丝网架珍珠岩复合墙板结构,轻钢框架由方钢管混凝土柱、H型钢梁、双L形带斜向加劲肋梁柱节点及预制混凝土楼板构成,钢丝网架珍珠岩复合墙板由钢丝网砂浆内外叶复合珍珠岩板夹心聚苯板构成,钢丝网架珍珠岩复合墙板单元包裹咬合轻钢框架,墙板单元间采用企口连接。进行了两层轻钢框架–钢丝网架珍珠岩复合墙板足尺结构的振动台试验,激振包括白噪声在内的57个工况,各工况的地震动峰值加速度PGA在0.07g~1.50g,分析结构的破坏过程、刚度退化、位移、应变等动力响应。结果表明:轻钢框架与钢丝网架珍珠岩复合墙板共同工作性能良好,钢丝网架珍珠岩复合墙板对结构刚度有显著的贡献;随地震峰值加速度的增大,结构自振频率降低,阻尼比增大;在8度设防地震作用下结构最大层间位移角为1/361,基本处于弹性状态;8度罕遇地震作用下,结构没有明显的破坏;在极罕遇地震作用下,外墙板损伤明显,轻钢框架损伤较轻;钢丝网架珍珠岩复合墙板与轻钢框架包裹咬合式柔性连接,具有滑移摩擦消能减震的作用。该结构体系在村镇低层住宅建筑中有广阔的应用前景。

框支密肋复合墙结构地震易损性研究

地震易损性分析通过概率计算建立地震强度和结构损伤之间的关系,可以实现结构地震风险预测和评估。为了对框支密肋复合墙结构在不同地震强度下的抗震能力进行评估,该文采用OpenSEES有限元软件,选用密肋复合墙的刚架-等效斜撑简化模型,建立结构整体分析模型,基于增量动力时程分析(IDA)和易损性分析,研究不同参数的变化对结构抗震性能的影响。结果表明:转换层刚度比的变化对结构性能影响显著,结构竖向布置均匀对抗震有利,建议8度区框支密肋复合墙结构的刚度比取值为1.0~2.5;肋柱数量、砌块强度的变化可对结构的抗震性能产生影响,应合理选择;混凝土强度等级对结构的抗震性能影响较大,在实际应用中应在满足规范要求的前提下选择较大的混凝土强度等级。

外肋板式钢板混凝土组合剪力墙与钢梁节点抗震性能试验研究

外肋板式钢板混凝土组合剪力墙与钢梁节点是一种新型墙梁节点,设计并制作了四个足尺的外肋板式钢板混凝土剪力墙与钢梁节点模型试件进行低周往复加载试验,研究钢梁跨高比、外肋板宽厚比以及设置栓钉对试件的滞回性能、延性、耗能和刚度退化等抗震性能的影响。结果表明该节点具有良好的延性和耗能能力,外肋板对节点承载力有较大提升,跨高比较小的试件在弹塑性阶段具有更好的耗能能力,改变外肋板宽厚比和在墙侧设置栓钉对该节点初始刚度无明显影响,该节点荷载有两种传递方式,一种由外伸梁传至外肋板,再由外肋板传至剪力墙;另一种直接由外伸梁传递至剪力墙,前者占比更高。

复合配筋混凝土剪力墙抗震性能数值分析

通过给暗柱配置预应力钢绞线,墙身配置普通钢筋的复合配筋方式设计了3面复合配筋预应力钢绞线剪力墙,并设计了1面普通钢筋混凝土剪力墙进行对比。基于Diana有限元分析软件对两种墙体进行了拟静力分析,对比研究了暗柱不同配筋形式及轴压比对剪力墙滞回性能、承载性能、变形性能、刚度退化、耗能能力及裂缝开展的影响。结果表明:与普通钢筋混凝土剪力墙相比,复合配筋预应力钢绞线剪力墙可以有效地提高构件的承载性能,并抑制裂缝的开展;随着轴压比的增大,构件承载力有所提升,但延性显著下降。