全装配式预制混凝土结构梁柱组合件抗震性能试验研究

采用足尺模型对比试验方法对现浇高强混凝土梁柱组合件、预制混凝土结构高强混凝土后浇整体式梁柱组合件和高强预制混凝土结构全装配式梁柱组合件在低周反复荷载作用下的开裂破坏形态、滞回特性、骨架曲线、强度与刚度退化特性、耗能能力、节点核心区域的剪切变形、梁端与柱端的转动变形等抗震性能指标进行了系统研究。结果表明：高强预制混凝土结构后浇整体式梁柱组合件与现浇高强混凝土结构梁柱组合件具有相同的抗震能力，全装配式预制混凝土梁柱组合件的抗震性能和主要抗震性能指标与现浇高强混凝土梁柱组合件和预制混凝土结构后浇整体式梁柱组合件存在明显的差异。对于实际工程应用，应采取必要措施增加全装配式节点的耗能能力。     

新型全螺栓分层装配式节点抗震性能分析

在装配式结构中,梁柱节点连接方式不仅影响装配效率,抗震性能在结构抵抗地震作用中更起到决定性的作用。通过改变节点构造将塑性铰从核心区向梁上发展,提出了一种新型全螺栓分层装配式连接节点,以提高节点抗震性能。采用有限元分析软件建立新型全螺栓分层装配式节点模型,通过与试验结果对比确定方法的有效性。分析了方钢管柱壁厚、节点域翼缘厚度、内套筒壁厚和内套筒凸起高度等参数对节点抗震性能的影响规律。获得节点破坏过程和破坏模式,并得到滞回性能、刚度和强度退化等抗震特性,为新型全螺栓分层装配式节点的设计提供了可靠依据。     

新型装配式混凝土框架连接节点抗震性能试验

为推广装配式混凝土框架结构的应用,提出3种不同的新型装配式钢筋混凝土框架中节点连接形式,进行低周往复荷载试验。对比各试件的破坏形态、滞回性能、刚度退化、累积耗能和节点剪切变形等抗震指标。研究结果表明:采用方钢管连接的装配式混凝土节点呈现梁端弯曲破坏,采用工字钢连接或对拉螺栓连接的节点呈现节点核心区剪切破坏。采用方钢管的连接形式既能改善节点核心区的破坏形态,又能提高其承载能力、变形能力、耗能能力和梁端转动能力,同时显著改善节点的滞回特性,减小核心区的剪切变形。在弹塑性和塑性变形阶段,采用方钢管连接形式的装配式混凝土节点的抗震性能优于工字钢连接和对拉螺栓连接的节点。此外,采用工字钢连接形式比对拉螺栓连接形式的节点具有更高的承载能力、耗能能力和较小的核心区剪切变形。     

预制装配框架结构灌浆套筒式节点试验研究

预制装配混凝土结构竖向钢筋连接方法有很多,而近年来比较推崇的是钢筋套筒灌浆连接。这种钢筋连接方法在做法上较为简单方便,只需将钢筋插入预制好的钢套管内,并浇筑微膨胀灌浆料,待灌浆料凝结硬化便将两根钢筋连接到了一起。通过进行装配式混凝土框架边节点和相应的普通现浇边节点的低周反复荷载试验,来评价装配式混凝土框架边节点的力学和抗震性能。结果表明:装配式混凝土框架节点具有与现浇节点相近的抗震性能,实际工程中可参照现浇混凝土框架结构,按照等同设计原则进行装配式混凝土框架结构设计。     

基于OpenSEES的FRP加固装配式梁柱节点抗震性能研究

为研究FRP加固对装配式梁柱节点及整体框架结构抗震性能的影响,本文基于OpenSEES有限元程序,建立了某装配式梁柱节点的有限元计算模型,以相关试验为基础,比较验证了所建有限元模型的可靠性。同时选用合适的FRP约束混凝土本构关系来表征FRP对混凝土性能的提升作用,设计3种装配式梁柱节点FRP加固方案,并通过有限元数值模拟,分析比较了节点承载力、滞回曲线和位移延性的差异,考察了FRP包裹层数等因素对节点承载力的影响。随后对装配式框架结构设计了3种FRP加固方式,并选取3条地震波进行结构动力时程分析以考察结构抗震性能。结果表明：FRP环向包裹加固及纵向加固能分别有效提高节点的延性能力和承载能力;FRP加固的装配式框架结构具有更好的延性及耗能能力,能有效增强结构的整体抗震性能,为装配式结构FRP加固设计提供参考。     

某新型梁柱节点的装配式钢筋混凝土框架结构基于性能的抗震设计研究

在一种新型无黏结预应力装配式混凝土梁柱框架节点抗震性能试验基础之上，使用基于位移的抗震设计方法对新型框架节点的无黏结预应力装配式钢筋混凝土框架结构进行整体抗震设计研究。首先使用有限元软件sap2000进行预应力三维结构设计并建立相应的有限元模型，同时建立该梁柱节点的梁恢复力模型，进而实现自定义塑性铰本构关系研究该装配式框架结构。使用pushover分析去表征结构的抗震性能，对比研究不同目标位移下的相应性能水平要求。通过施加Y方向均匀分布荷载对结构进行弹塑性推覆分析，对结构的层间位移角、破坏机制进行分析讨论。结果表明：按照"功能良好""生命安全""防止倒塌"三水平的设计均达到预期结果，各层层间位移角和薄弱层的性能均能满足规范的相应要求。并选用三条地震波对结构进行弹塑性动力时程分析，表明基于该新型梁柱节点的装配式结构在基于位移的抗震设计中可以较好满足相关抗震性能水平要求。     

装配式圆钢管柱-钢梁节点抗震性能试验研究

为验证新型装配式圆钢管柱-钢梁节点的破坏模式及抗震性能,进行了3个十字形节点的低周反复循环加载试验。研究了不同试件节点的破坏模式、滞回性能、延性及耗能性能等。试验结果表明:试件的位移延性系数为3.38~3.44,能量耗散系数为1.72~2.25,节点具有良好的滞回性能、延性及耗能能力,满足现行规范设计要求。建议在采用新型装配式节点时,梁柱连接处可同时采用加强型连接或骨式连接,以获得良好的抗震性能。     

预制装配式剪力墙结构墙板节点抗震性能研究

为掌握预制装配式剪力墙结构墙板节点的抗震性能,对2个现浇试件和2个预制装配式试件进行了拟静力试验.结合非线性分析手段,从承载能力、变形能力、受力机理以及破坏模式等方面综合分析了其抗震性能,并初步探讨了墙板连接钢筋的合理直径.分析结果表明:与现浇试件相比,预制装配式试件承载能力较高,位移延性系数相同,滞同环均较饱满,具有...     

不同加固方式对混凝土梁柱节点抗震性能的影响

在简要分析了汶川地震中钢筋混凝土框架结构的震害后,通过芳纶布(AFRP)加固钢筋混凝土框架节点的抗震性能试验,研究了不同加固方式对混凝土梁柱节点抗震性能的影响。研究结果表明:采用AFRP加固后的梁柱节点,极限承载力和抗震性能得到了显著改善,破坏形式由脆性破坏变为延性破坏。     

梁端楔形翼缘连接钢框架抗震性能和抗震设计研究

根据两跨两层梁端楔形翼缘连接钢框架试件的低周反复加载试验,研究了梁端楔形翼缘连接钢框架结构在地震作用下的滞回性能、耗能机制、耗能能力和破坏形态。结果显示,试件破坏模式为延性,塑性铰出现在梁翼缘变化处,远离梁柱交界,梁端楔形翼缘连接钢框架具有良好的抗震性能。针对梁端楔形翼缘连接钢框架的特点,提出了强柱弱梁、强节点弱杆件和节点域抗震设计要求。     

预制钢筋混凝土剪力墙结构抗震性能研究进展（Ⅱ）：结构性能研究

阐述了预制钢筋混凝土剪力墙结构抗震性能研究的重要性和预制钢筋混凝土剪力墙结构抗震性能研究的最新进展。综述了国内外预制钢筋混凝土剪力墙结构设计规范以及设计方法的研究进展。指出常规预制装配式钢筋混凝土剪力墙结构的抗震性能较差,在地震作用下,主要靠结构构件连接处的损伤和结构构件损坏来消耗能量;无粘结后张拉预应力预制混凝土剪力墙结构,在地震作用下具有自恢复中心能力和良好的抗震能力,但该结构体系的耗能能力不足。认为在预制钢筋混凝土剪力墙结构中设置耗能减震元件,或将预制钢筋混凝土剪力墙结构设计成隔震结构,将有效提高预制钢筋混凝土剪力墙结构的抗震性能。该类预制装配式剪力墙结构的抗震性能有待于进一步研究。     

Seismic performance of interior precast concrete beam-column connections with T-section steel inserts under cyclic loading

An experimental investigation was conducted to study the performance of precast beam-column concrete connections using T-section steel inserts into the concrete beam and joint core, under reversed cyclic loading. Six 2/3-scale interior beam-column subassemblies, one monolithic concrete specimen and five precast concrete specimens were tested. One precast specimen was a simple connection for a gravity load resistant design. Other precast specimens were developed with different attributes to improve their seismic performance. The test results showed that the performance of the monolithic specimen M1 represented ductile seismic behavior. Failure of columns and joints could be prevented, and the failure of the frame occurred at the flexural plastic hinge formation at the beam ends, close to the column faces. For the precast specimens, the splitting crack along the longitudinal lapped splice was a major failure. The precast P5 specimen with double steel T-section inserts showed better seismic performance compared to the other precast models. However, the dowel bars connected to the steel inserts were too short to develop a bond. The design of the precast concrete beams with lap splice is needed for longer lap lengths and should be done at the beam mid span or at the low flexural stress region.     

橡胶集料风积沙混凝土柱抗震性能试验研究

为研究橡胶集料风积沙混凝土柱的抗震性能,制作了4根相同尺寸的混凝土柱试件,其中包括普通混凝土柱、风积沙混凝土柱、橡胶集料混凝土柱和橡胶集料风积沙混凝土柱。通过低周反复荷载试验,分析各试件的破坏现象、滞回曲线、骨架曲线、刚度退化和延性等抗震性能指标。在试验的基础上,根据能量耗散原理建立累积损伤评价模型,并对结构进行了累积损伤分析。研究结果表明:10%橡胶集料的掺入能够改善混凝土柱的变形能力,但混凝土柱的承载力有所降低;30%风积沙的掺入可以改善混凝土柱的抗震性能;橡胶集料风积沙混凝土柱具有较好的滞回性能,且耗能能力和延性性能明显高于其余试件,柱的抗震性能得到提高;通过累积损伤分析表明:适量掺入橡胶集料和风积沙的可以有效减缓试件的损伤,且该累积损伤模型能够较好的反映出各试件的损伤程度。     

夹层橡胶垫耗能低剪力墙承载力分析

本文针对低剪力墙结构延性差、耗能能力差、结构抗震性能较差等问题，提出夹层橡胶垫耗能低剪力墙结构，并对其承载力情况进行分析，结果表明，耗能墙的减震效果随夹层橡胶垫初始刚度值的增大而减小。当夹层橡胶垫的初始刚度选取范围为同截面整体墙初始刚度的0．5％—70％，其对应的周期范围为0．3—3．1s，层间剪力降低26％—98％。     

Probabilistic seismic assessment of multistory precast concrete frames exposed to corrosion

Seismic design of concrete structures is currently based on time-invariant capacity design criteria which do not account for environmental hazards. The significant progressive decay of strength and ductility of concrete structures exposed to damage, in particular due to reinforcing steel corrosion, shows that this approach should be revised to consider the deterioration over time of the seismic performance. This is important also for precast systems, for which most of structural members are often directly exposed to the atmosphere and environmental aggressiveness. This paper presents a probabilistic approach for the lifetime assessment of seismic performance of concrete structures considering the interaction of seismic and environmental hazards. The effectiveness of the proposed approach is shown by its application to multistory precast buildings exposed to corrosion. The results show that structures designed for the same seismic action could have different lifetime seismic performance depending on the environmental exposure. These results emphasize the importance of a life-cycle approach to both seismic assessment of existing buildings and seismic design of new structures, and indicate that capacity design criteria need to be properly revised to consider the severity of the environmental exposure.     

Horizontal cladding panels: in-plane seismic performance in precast concrete buildings

The paper investigates the in-plane performance of horizontal precast reinforced concrete cladding panels, typically adopted in one-storey precast industrial and commercial buildings. Starting from in-field observations of cladding panels failures in recent earthquakes, the seismic performance of typical connections is evaluated by means of experimental tests on full-scale panels under quasi-static cyclic loading. The failure mechanisms highlight the vulnerability of such connections to relative displacements and, therefore, the need to accurately evaluate the connections displacement demand and capacity. An analytical model is developed to describe the force–displacement relationship of the considered connections and compared to the experimental results. In order to determine the seismic vulnerability of such connections and provide design recommendations, linear and nonlinear analyses are conducted taking as reference a precast concrete structure resembling an industrial precast building. The results of the analyses show the importance of a correct estimation of the column’s lateral stiffness in the design process and how an improper erection procedure leads to a premature failure of such connections.     

Shake-table testing of a self-centering precast reinforced concrete frame with shear walls

The seismic performance of a self-centering precast reinforced concrete (RC) frame with shear walls was investigated in this paper. The lateral force resistance was provided by self-centering precast RC shear walls (SPCW), which utilize a combination of unbonded prestressed post-tensioned (PT) tendons and mild steel reinforcing bars for flexural resistance across base joints. The structures concentrated deformations at the bottom joints and the unbonded PT tendons provided the self-centering restoring force. A 1/3-scale model of a five-story self-centering RC frame with shear walls was designed and tested on a shake-table under a series of bi-directional earthquake excitations with increasing intensity. The acceleration response, roof displacement, inter-story drifts, residual drifts, shear force ratios, hysteresis curves, and local behaviour of the test specimen were analysed and evaluated. The results demonstrated that seismic performance of the test specimen was satisfactory in the plane of the shear wall; however, the structure sustained inter-story drift levels up to 2.45%. Negligible residual drifts were recorded after all applied earthquake excitations. Based on the shake-table test results, it is feasible to apply and popularize a self-centering precast RC frame with shear walls as a structural system in seismic regions.     

基于钢筋拉压力传递的预制空心板残余抗震性能研究

为提升建筑质量,分析在循环往复荷载作用下预制空心板整体抗震性能,研究基于钢筋拉、压应力传递的预制空心板残余抗震性能.制备不含钢筋预制空心板结构试件:不含钢筋试件、未使用钢筋拉压力传递间接搭接试件、使用钢筋拉、压应力传递灌孔构造边缘构建试件,对各试件循环施加地震荷载,记录各试件性能变化情况.试验结果表明,相比于压剪破坏的...