圆形钢管混凝土柱的基础连接件

钢管混凝土柱促进了经济且快速的建设方式。两者的组合增大了结构钢和混凝土的强度和刚度,使用钢管作为模板和核心混凝土的约束减少了工作量。钢管混凝土柱为混凝土和钢材提供了一个共生关系来缓和其不良的失效模式,激发了各种材料的最优性能(混凝土和钢材)。综合作用下,混凝土抗压强度和刚度增大,延缓和抑制了钢管的局部屈曲,并提升其延展性和抗力。矩形钢管混凝土柱与圆形钢管混凝土柱都被应用于实际建设生产中,但由于圆形钢管混凝土柱可以提供更强的混凝土约束和综合作用而拥有更好的性能。对于圆形钢管混凝土柱来说,其缺少可靠的、有延展性的连接件。对这方面的研究调查进行介绍,包括关于圆形钢管混凝土柱柱脚或钢筋混凝土地基柱的简便经济的连接件的开发设计过程,并介绍和评价了桥梁结构中的桩帽与宽桩梁。这种连接件不需要销子和内在的加固就能将钢管与基脚或桩梁相连接。试验分析研究和评估了这种连接件的非弹性抗震性能,并确立了设计标准。将1个装配这种连接件的钢管混凝土柱的抗震性能与传统的钢筋混凝土柱相比较。结果显示,此种连接件进一步增强了组合柱的承载力。这种形式在地震荷载下能提供极佳的延展性和非弹性变形能力,甚至在大侧移情况下也能减轻损害。     

装配式钢管混凝土柱-盖梁节点抗震性能试验研究

装配式钢管混凝土柱-盖梁节点施工简单、工期短,逐渐在桥梁建设中广泛运用。提出一种带抗剪环的新型钢管混凝土柱-盖梁节点,介绍装配式节点在桥梁施工中的施工工序。设计7个钢管直径超过508mm 的大规模节点试件,通过低周反复荷载试验对6个抗剪环节点和1个钢筋笼节点进行了地震响应分析。对比分析节点的破坏形态、有效刚度、延性、滞回性能和极限承载能力等力学特性,得到如下结论：钢管混凝土柱出现初始撕裂时的位移随着构件的有效刚度增大而增大,盖梁的开裂情况则随着钢管混凝土柱埋深的增加而减少。埋深相近的情况下,抗剪环节点的极限荷载承载力大于钢筋笼节点;抗剪环节点的整体延性随着径厚比D/t的增大而减小。     

基于位移的圆钢管混凝土柱抗震设计方法研究

对基于位移的圆钢管混凝土柱抗震设计方法进行研究:首先对基于性能抗震设计方法的基本概念和原理进行介绍;并给出钢管混凝土柱基于位移抗震设计的一般过程;以解决等效刚度、等效阻尼等设计中的关键问题;最后对圆钢管混凝土柱性能设计进行具体分析,并研究相关参数的影响。结果表明:在通常范围内,第二阶段刚度系数对滞回阻尼的影响不大;随着轴压比的增加,钢管壁厚度增加,柱延性系数增加;随着截面尺寸增加,钢管壁厚度减小,屈服弯矩也减小。     

配筋圆钢管自密实混凝土柱抗震性能试验研究

通过7根配筋圆钢管自密实混凝土柱和1根圆钢管自密实混凝土对比柱的低周反复荷载试验,研究了纵筋配筋率、轴压比和钢管壁厚对配筋圆钢管自密实混凝土柱的承载力、延性、耗能能力和性能退化规律的影响。试验结果表明:配筋圆钢管自密实混凝土试件的滞回曲线饱满,表现出良好的抗震性能,在加载中后期,配筋试件的纵筋屈服,强度得到发挥,配筋圆钢管自密实混凝土试件的承载力和延性较普通圆钢管自密实混凝土试件均有不同程度提高,同时,耗能性能提高,且纵筋配筋率越大,配筋圆钢管自密实混凝土试件的承载力和延性也越大。轴压比和钢管壁厚对配筋圆钢管自密实混凝土柱抗震性能的影响规律与普通圆钢管混凝土柱相同。     

Analysis on axial compressive performance of embedded circular steel tube totally-recycle concrete composite columns

为研究全再生混凝土柱内配钢管后的轴压力学性能,设计5个内置钢管全再生混凝土组合柱试件和3个对比试件进行试验,分析体积配箍率和钢管面积比对试件承载力、延性和损伤性能的影响规律以及内配钢管后的组合效应。研究表明：钢管混凝土柱达到峰值荷载时刻滞后于中空钢筋混凝土柱,即在管外混凝土达到极限状态后,核心钢管混凝土逐渐发挥作用;随着体积配箍率的增加,组合柱的承载力和延性整体呈增长趋势,累积损伤增长变慢;提高钢管面积比,组合柱承载力降低,延性增强,提前进入损伤状态,但后期损伤发展缓慢;CECS 188:2005的计算结果与试验结果吻合良好,该规程可用于内置钢管全再生混凝土组合柱轴压承载力设计。     

传统风格建筑方形SRC-圆形RC变截面组合柱抗震性能试验研究

为研究传统风格建筑方形型钢混凝土(SRC)-圆形钢筋混凝土(RC)变截面组合柱的抗震性能,对2个足 尺传统风格建筑变截面组合柱进行了低周反复加载试验,得到了试件的破坏形态、滞回特性、刚度和强度退 化、延性及耗能性能。研究表明：传统风格建筑方形SRC-圆形RC变截面组合柱的破坏主要是由变截面处上柱 型钢和钢筋屈服及混凝土压碎剥落造成的;试件滞回曲线饱满,刚度和强度退化小;破坏时,试件的位移延 性系数介于3.18～3.76之间,等效黏滞阻尼系数介于0.289～0.338之间,具有良好的变形和耗能性能。在试 验基础上,利用ABAQUS建立试件三维模型,进行了混凝土强度、轴压比、型钢屈服强度、上下柱线刚度等参 数对其抗震性能影响的参数分析。试验及分析结果表明：随混凝土强度、型钢屈服强度增大,试件的水平承 载力增大,但其延性降低;增大轴压比,试件的水平承载力降低,延性系数减小;而随上、下柱线刚度比增 大,试件的水平承载力和延性增大。     

钢管混凝土柱螺栓连接钢梁节点的抗震性能分析

为了改进施工过程,同时确保房屋的抗震性能,提出了一种新型的连接类型,用于钢管混凝土柱和钢梁的连接处设计。该连接具有外伸端板的特性,出厂前与钢梁焊接在一起,然后在现场用高强钢将其与钢管混凝土柱螺栓连接。对这种螺栓连接端板节点的抗震性能进行试验研究,并通过对3个足尺节点模型进行试验,评估了混凝土楼板和削弱型梁截面对其的影响。试验结果表明:楼板对节点强度的作用显著,削弱型梁截面能有效地将屈曲区域转移到远离焊接点的位置。同时,螺栓连接端板节点的分析模型也采用OPENSEES1.7.3模拟了试验结果。     

Flexural strength analysis of non-post-tensioned and post-tensioned concrete-filled circular steel tubes

Concrete-filled circular steel tubes (CFT) have recently gained significant attention for their enhanced strength and ductility over the conventional steel and reinforced concrete construction. The concrete compressive strength is significantly increased by the lateral confinement provided by the steel tube and local buckling of the steel tube is restrained by the concrete infill. This paper investigates the further enhancement of these composite actions due to post-tensioning the concrete cores inside circular steel tubes. The flexural behavior of a post-tensioned CFT as well as a non-post-tensioned CFT was studied experimentally and analytically. A numerical algorithm for predicting the moment capacities of circular CFT, with or without the post-tensioning effects, has been validated against the test results by the authors as well as those published in the literature.     

约束钢管混凝土柱的开发研究(英文)

本文提出了一种更适合抗震设计的新型钢管混凝土体系———约束钢管混凝土柱体系。它建立在清楚的力学概念基础上,其设计着眼于在可能出现塑性铰的部位附加横向约束以控制钢管的局部屈曲和更有效地约束混凝土。这一新型钢管混凝土柱体系兼具了钢管混凝土及套管混凝土柱两者的优点,克服了传统钢管混凝土柱的抗震缺陷,为抗震地区的高层结构和桥梁设计提供了理想的选择。在本研究的第一阶段,作者们对FRP约束的圆钢管柱和钢板约束的方钢管柱进行了模拟地震力的加载试验。其结果验证了约束钢管混凝土柱的良好抗震性能。     

矩形钢管混凝土柱-混凝土梁搭接式节点抗震性能研究

在现有钢管混凝土柱与混凝土梁连接形式基础上,提出一种新型搭接式钢管混凝土柱-混凝土梁节点,通过低周反复荷载试验和数值模拟分析,研究了节点的破坏形态、承载能力、刚度退化、延性及耗能能力等,分析了梁端纵筋和搭接牛腿翼缘的应变发展规律。结果表明:钢管混凝土柱-混凝土梁搭接式节点表现出典型的混凝土梁端塑性铰破坏模式,符合“强节点、弱构件”的抗震设防理念; 节点的滞回曲线饱满,捏缩现象较轻,刚度退化明显,强度退化较小,具有较好的延性及耗能能力; 梁纵筋及牛腿各测点中搭接牛腿端部截面应变最大,通过搭接连接方式可实现梁端弯矩和剪力的有效传递,但搭接牛腿长度不足会使节点发生锚固破坏; 在节点设计时,应保证足够的搭接长度,以实现钢筋混凝土梁纵筋在弯剪复合受力状态下锚固性能的可靠性,充分发挥节点的抗震耗能能力; 有限元计算结果与试验结果吻合良好,该模型能够准确反映节点在实际受力情况下的力学特性,所得结论可为此类新型搭接式节点工程应用提供技术支撑。     

Mechanical behavior of stirrup-confined circular concrete-filled steel tubular stub columns under axial loading

通过井字形拉筋、米字形拉筋和圆环箍筋等3组拉筋约束形式带拉筋圆钢管混凝土短柱轴压性能对比试验,研究不同拉筋约束形式、拉筋体积配箍率对圆钢管混凝土轴压短柱的承载力和延性等的影响;采用合理的混凝土三轴受力本构模型和钢材本构模型,应用ABAQUS非线性有限元分析软件对带拉筋圆钢管混凝土轴压短柱进行三维有限元分析,有限元计算结果与试验结果吻合较好;在此基础上,分析了带拉筋圆钢管混凝土轴压短柱中钢管、拉筋或箍筋、核心混凝土之间的组合作用。结果表明：井字形拉筋圆钢管混凝土轴压短柱的承载力最高,延性最好,钢管、拉筋和核心混凝土之间的组合作用最强;提高体积配箍率可以有效提高圆钢管混凝土短柱的轴压承载力和延性。     

Full‐scale experimental assessment of new connection for columns in vertically mixed structures

More stiffness of concrete frames on one hand and fewer weight of steel frames on the other hand motivates using a composite system so called vertically mixed structures. The reinforced concrete and steel frames are connected together at a story called transition story. A major challenge for the designers is the connection columns in the transition story for proper transferring of efforts and preventing stress concentration phenomenon. There are some suggestions, in the literature, to build a transition composite column instead of constructing a local connection. Four full‐scale specimens of three connection types are constructed and tested experimentally under cyclic load to investigate hysteresis characteristics, failure mechanism, deformability, and energy dissipation capacity of the model. A novel through bolt lap connection adapted from concrete‐filled tube (CFT) column is proposed. Finally, backbone curves of proposed column for more accurate seismic studies are presented. No evident sign of local failure is observed in the proposed connection. Placing the steel around the reinforced concrete column section prepares the maximum possible geometrical dimensions for the steel column section and the connection. The experimental results show no strength loss for the new proposed connection under two different axial loads in lateral cyclic loading up to 4% drift.     

复式钢管混凝土柱与H形钢梁连接节点抗震性能试验研究

借鉴方钢管混凝土柱-钢梁外肋环板节点形式,将非梁柱连接面的柱两侧外肋环板改为竖贴于柱侧的竖向肋板并伸出与梁翼缘焊接,同时设置锚固腹板,形成复式钢管混凝土柱与H形钢梁连接节点。通过7个梁柱组合体试件的低周反复荷载试验,分析各试件的破坏过程及特征,并对试件的滞回性能、承载力、延性、耗能能力和承载力及刚度退化等抗震性能进行研究。研究结果表明：节点的破坏形态基本相同,梁端先屈曲,形成塑性铰;锚固腹板可有效提高节点的承载力和变形能力;竖向肋板外伸长度可提高试件的初始刚度,使梁端塑性铰外移,有效保护节点核心区;试件的滞回曲线呈明显的梭形,具有良好的承载力、延性及耗能能力;试件在整个加载过程中刚度退化现象明显,承载力退化很小,可应用于抗震设防地区。     

配置600MPa钢筋预制混凝土柱连接区抗震性能试验研究

设计了2个钢连接件连接和3个半灌浆套筒连接预制钢筋混凝土柱试件,对试件进行了低周反复加载试验,研究了预制柱的破坏形态、滞回曲线、骨架曲线、位移延性、钢筋应变、刚度退化以及耗能能力,分析了连接形式、轴压比等因素对其抗震性能的影响。试验结果表明:采用钢连接件连接的预制柱Z-1的抗震性能比预制柱Z-2要好;3个采用半灌浆套筒连接的预制柱均能有效传递荷载,结合面处未出现滑移错动。采用钢连接件连接的预制柱Z-1与半灌浆套筒连接预制柱的滞回曲线、耗能能力相当,但后者变形能力更强。轴压比较高的预制柱,骨架曲线下降段更陡,变形能力更弱,但耗能能力更强。采用大直径纵筋半灌浆套筒连接的预制柱承载力略有降低,骨架曲线下降段较陡,后期刚度衰减更快,变形能力更弱。     

Fiber element modeling for seismic performance of bridge columns made of concrete-filled FRP tubes

Concrete-filled fiber reinforced polymer (FRP) tubes (CFFT) are an alternative to reinforced concrete, providing for rapid construction with comparable strengths and higher ductility. Despite encouraging test data, it is not clear as to whether traditional analytical tools may be used for prediction of structural performance of CFFT, especially in seismic applications. This paper reports on modeling of CFFT either as cast-in-place reinforced or precast post-tensioned column in conjunction with a reinforced concrete (RC) footing. The model is verified against two earlier experimental programs at the member-level and subassembly-level. The model was then used to conduct a parametric study of different column configurations under a constant axial load and a reversed cyclic lateral load. Moreover, seismic performance of a typical CFFT column is compared with its RC counterpart under three different ground acceleration records. The study shows that seismic analysis of CFFT columns is possible using available analytical tools for conventional RC columns. Also, CFFT columns demonstrate superior performance over their RC counterparts in response to wide-ranging ground acceleration records. Fiber architecture of the FRP tube could be optimized for strength and ductility. Internal steel reinforcement and a minimum thickness of FRP tube are deemed necessary to provide adequate ductility and system integrity in seismic applications.     

不同方式连接下钢柱-一体式预制混凝土墙组合构件抗震性能试验研究

钢框架与内部混凝土墙形成的组合构件具有优越的抗震性能。为进一步分析钢柱-一体式预制混凝土墙不同方式连接（梁柱刚接与柱边焊接、梁柱刚接与柱边不焊、梁柱铰接与柱边焊接、梁柱铰接与柱边不焊）时的抗震性能,分别对4个不同连接形式的钢柱-一体式预制混凝土墙的1/2缩尺模型进行了低周往复加载试验。得到了该类构件的滞回曲线及骨架曲线,并通过分析各构件的试验现象、承载力、刚度、耗能能力、延性及应变和变形,得出了不同连接形式对该类构件抗震性能及受力机理的影响。试验结果表明：钢柱 一体式预制混凝土墙体呈现三道防线特征,其中混凝土墙板为第一道防线,内斜撑为第二道防线,边框为第三道防线。柱边焊接对构件的承载力、刚度及边框与内墙组合作用的影响最为明显;内支撑对构件的刚度贡献最为显著且对边框与内部墙板组合作用的发挥具有关键作用。节点铰接且柱边不焊的构件位移延性系数可达2.83,可按1/20作为其弹塑性最大层间位移角限值,其他连接方式的构件位移延性系数在1.22～1.53之间,建议按1/100作为其弹塑性层间位移角限值。按位移控制进行设计的结构推荐采用节点铰接且柱边不焊的构件,而按承载力控制进行设计的结构推荐采用节点刚接且柱边焊接的构件。     

后置钢管式钢筋混凝土柱轴压性能的监测与分析

后置钢管式钢筋混凝土柱是一种新型的加固方法,是在外包钢方法、套管约束混凝土方法以及钢管混凝土叠合柱的基础上提出的.采用后置钢管式钢筋混凝土柱对既有钢筋混凝土柱进行加固,是在原有钢筋混凝土柱四周凿出一部分混凝土形成空腔,外包钢板,二者之间的空腔灌浆形成钢管混凝土组合结构,且不改变原有柱的尺寸.在加固施工现场对后置式钢管混...     

Polymer concrete-filled steel tubes under axial compression

Concrete-filled steel tubular (CFT) structures are rapidly emerging as one of the inevitable structural systems for earthquake resistance, as they have been known to exploit the best attributes of both steel and concrete, resulting in higher stiffness, strength and ductility. However, the limitations imposed by certain drawbacks of cement concrete and which are not alleviated or moderated by the encasing steel tube, e.g. its high shrinkage, creep, brittleness, reactivity and low tensile strength, may be a hindrance to the rapid and diversified application of CFTs, in line with current emphasis on ductility-based seismic design. In this context, studies are presently being conducted on filled steel composite members, employing lighter, more ductile, high tensile strength and inert polymer-based fill materials for the steel tube. Findings of these studies relating to the elasto-plastic response of filled steel composite stub columns subjected to axial compression highlight the significant increase in strength and/or ductility of epoxy polymer concrete-filled steel columns.     

螺栓连接钢-混凝土组合T型节点抗震性能的试验研究

设计了三组高强、足尺的螺栓端板连接的钢梁-钢筋混凝土柱组合节点试件,完成了其在低周反复荷载作用下的受力性能试验研究。试验结果表明,该新型组合节点具有优良的抗震性能和优越的施工性,在高强螺栓端板连接设计中应适当加大螺栓承载力的安全储备。     

Punching shear strength and post-punching behavior of CFT column to RC flat plate connections

This paper summarizes full-scale test results on CFT (concrete filled tube) column to RC (reinforced concrete) flat plate connections subjected to gravity loading. CFT construction is gaining wide acceptance due to its various structural and constructional advantages. However, efficient details for CFT column to RC flat plate connections have not been proposed yet. Based on the strategies that maximize economical field construction, several connecting schemes were proposed and tested in this study. Test results showed that the proposed connections can exhibit punching shear strength and connection stiffness exceeding those of RC flat plate counterparts. A semi-analytical procedure is presented to model the behavior of CFT column to RC flat plate connections. The parameters needed to model the behavior from elastic to post-punching range are calibrated based on the test data of this study. The application of the proposed model to progressive collapse analysis is also illustrated.