带锚板的梁—墙平面外连接节点受力性能和破坏机理研究
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摘要
本课题属于《混凝土结构设计规范》修订组和重庆市科委联合资助的“梁-墙直交节点”系列研究项目的一部分,主要针对梁纵筋端部带锚固板的钢筋混凝土框架梁-剪力墙平面外连接节点的受力性能和破坏机理进行试验和理论研究。
已有梁-墙平面外连接节点试验表明,不论纵筋锚固长度是否达到规范要求,都可能发生墙体撕裂的局部拉脱式脆性破坏,造成梁-墙直交节点承载力和延性明显下降;现有理论对“拉脱式”破坏的受力模型和破坏机理都没有明确阐述,基于“等效框架”理论的平面外受弯计算方法必须保证节点不发生拉脱破坏的情况下才能适用。
本文完成了4个梁纵筋末端带不同钢板锚固措施的试件和1个仅加强暗柱和暗梁配筋试件的低周反复荷载试验,详细观察了试件的破坏过程,比较了不同锚固方案对梁-墙直交节点受力和变形性能的影响,分析了产生拉脱破坏的原因,提出了梁纵筋带钢板锚固措施的梁-墙直交节点的受力模型,并推导了此锚固措施下节点平面外抗拉脱承载力公式。论文主要结论如下:
①梁纵筋端部设置锚板,能有效地提高梁-墙直交节点抵抗平面外弯矩的能力,延迟“拉脱破坏”的发生;墙较薄时,需设置双锚板才能避免“推脱”破坏的发生;仅考虑节点的“宏观受力”不能保证节点的有效受力。
②梁-墙直交节点的“拉脱式破坏”是一种有别于传统意义的墙肢平面外受弯破坏的全新破坏形态。梁-墙直交节点由宏观受力和局部受力共同作用,当临界截面上宏观受力产生的剪应力和局部受力产生的剪应力叠加大于混凝土的有效抗拉强度时,节点就将发生拉脱式破坏,而合理的钢板锚固措施可以增大拉脱临界截面面积,从而减小临界截面剪应力,控制拉脱式破坏的发生。
③本文根据临界截面应力叠加方法推导出的梁纵筋在带锚板锚固措施下节点平面外抗拉脱承载力公式,与试验结果吻合较好。
This dissertation is a part of the research project named‘Beam-wall Out-of-plane Joint’which is jointly sponsored by the organization for revising‘Design Code for Concrete Structure’and Science Committee of ChongQing City. The mechanical behavior and the failure mechanism of reinforced concrete beam-wall out-of-plane joint with anchor plate at the end of longitudinal reinforcement of beam were studied experimentally and theoretically.
The partially brittle peel-off failure occurred in the past experiments of out-of-plane beam-wall joint no matter the development length of bar met the required of RC Structure Code or not, would decrease the load capacity and ductility significantly. The force model and failure mechanism according to existing theory were still not well understood. Moreover, the calculating method of the bending capacity of out-of-plane, based on the“Equivalent Frame”theory, is not suitable unless it can be ensured that the peel-off failure wouldn't occur.
The low cycle reversed loading experiments including four specimens with different anchor plates at the end of longitudinal reinforcement of beam and one with strengthened concealed column and concealed beam without anchor plate were completed. The failure process had been observed , the influences of different anchoring methods on mechanical behavior and deformation behaviour had been compared, and the reason of peel-off failure had been analysed. Also, the paper had put forward the force model of beam-wall orthogonal joint with anchor plate at the end of bar in the beam, and deduced the calcution formular of the bearing capacity of resisting peel-off failure of out-of-plane joint with anchor plate.
Main results are as follows:
①.Setting anchor plate at the end of longitudinal reinforcement of beam, can increase the bending capacity of out-of-plane beam-wall orthogonal joint effectively. The double-plate should be fixed at the end of bar to ensure the joint with thin wall against the peel-off failure. And the mechanism behavior can’t be guaranteed ,considering the macro forces only.
②.The peel-off failure of beam-wall orthogonal joint , which caused by the out-of-plane bending of wall, was a new kind of failure, which was different form the traditional out-of-palne bending failure. The beam-wall orthogonal joint was subjected to macro force and partial force at the same time. The peel-off failure would occur when the shear stress, which was superposed by macro force and partial force, was higher than the effective tensile strength. And the reasonable plate anchoring method can enlarge the area of critical section, and reduce the shear stress so as to make the peel-off failure in control.
③.The calculation formula of the bearing capacity of resisting peel-off failure of out-of-plane joint with anchor plate was deduced, according to the stress superposition method in the critical section, which coincides with the results of experiments well.
已有梁-墙平面外连接节点试验表明,不论纵筋锚固长度是否达到规范要求,都可能发生墙体撕裂的局部拉脱式脆性破坏,造成梁-墙直交节点承载力和延性明显下降;现有理论对“拉脱式”破坏的受力模型和破坏机理都没有明确阐述,基于“等效框架”理论的平面外受弯计算方法必须保证节点不发生拉脱破坏的情况下才能适用。
本文完成了4个梁纵筋末端带不同钢板锚固措施的试件和1个仅加强暗柱和暗梁配筋试件的低周反复荷载试验,详细观察了试件的破坏过程,比较了不同锚固方案对梁-墙直交节点受力和变形性能的影响,分析了产生拉脱破坏的原因,提出了梁纵筋带钢板锚固措施的梁-墙直交节点的受力模型,并推导了此锚固措施下节点平面外抗拉脱承载力公式。论文主要结论如下:
①梁纵筋端部设置锚板,能有效地提高梁-墙直交节点抵抗平面外弯矩的能力,延迟“拉脱破坏”的发生;墙较薄时,需设置双锚板才能避免“推脱”破坏的发生;仅考虑节点的“宏观受力”不能保证节点的有效受力。
②梁-墙直交节点的“拉脱式破坏”是一种有别于传统意义的墙肢平面外受弯破坏的全新破坏形态。梁-墙直交节点由宏观受力和局部受力共同作用,当临界截面上宏观受力产生的剪应力和局部受力产生的剪应力叠加大于混凝土的有效抗拉强度时,节点就将发生拉脱式破坏,而合理的钢板锚固措施可以增大拉脱临界截面面积,从而减小临界截面剪应力,控制拉脱式破坏的发生。
③本文根据临界截面应力叠加方法推导出的梁纵筋在带锚板锚固措施下节点平面外抗拉脱承载力公式,与试验结果吻合较好。
This dissertation is a part of the research project named‘Beam-wall Out-of-plane Joint’which is jointly sponsored by the organization for revising‘Design Code for Concrete Structure’and Science Committee of ChongQing City. The mechanical behavior and the failure mechanism of reinforced concrete beam-wall out-of-plane joint with anchor plate at the end of longitudinal reinforcement of beam were studied experimentally and theoretically.
The partially brittle peel-off failure occurred in the past experiments of out-of-plane beam-wall joint no matter the development length of bar met the required of RC Structure Code or not, would decrease the load capacity and ductility significantly. The force model and failure mechanism according to existing theory were still not well understood. Moreover, the calculating method of the bending capacity of out-of-plane, based on the“Equivalent Frame”theory, is not suitable unless it can be ensured that the peel-off failure wouldn't occur.
The low cycle reversed loading experiments including four specimens with different anchor plates at the end of longitudinal reinforcement of beam and one with strengthened concealed column and concealed beam without anchor plate were completed. The failure process had been observed , the influences of different anchoring methods on mechanical behavior and deformation behaviour had been compared, and the reason of peel-off failure had been analysed. Also, the paper had put forward the force model of beam-wall orthogonal joint with anchor plate at the end of bar in the beam, and deduced the calcution formular of the bearing capacity of resisting peel-off failure of out-of-plane joint with anchor plate.
Main results are as follows:
①.Setting anchor plate at the end of longitudinal reinforcement of beam, can increase the bending capacity of out-of-plane beam-wall orthogonal joint effectively. The double-plate should be fixed at the end of bar to ensure the joint with thin wall against the peel-off failure. And the mechanism behavior can’t be guaranteed ,considering the macro forces only.
②.The peel-off failure of beam-wall orthogonal joint , which caused by the out-of-plane bending of wall, was a new kind of failure, which was different form the traditional out-of-palne bending failure. The beam-wall orthogonal joint was subjected to macro force and partial force at the same time. The peel-off failure would occur when the shear stress, which was superposed by macro force and partial force, was higher than the effective tensile strength. And the reasonable plate anchoring method can enlarge the area of critical section, and reduce the shear stress so as to make the peel-off failure in control.
③.The calculation formula of the bearing capacity of resisting peel-off failure of out-of-plane joint with anchor plate was deduced, according to the stress superposition method in the critical section, which coincides with the results of experiments well.
引文
[1]中华人民共和国国家标准.GB50010-2002.混凝土结构设计规范[M].北京.中国建筑工业出版社.2002.
[2]中华人民共和国行业标准.JGJ3-2002,J186-2002.高层建筑混凝土结构技术规程[M].北京.中国建筑工业出版社.2002.
[3] KWAN A K H, CHAN W T. Out-of-plane beam wall joints in tall building structures [J]. Proceedings of the Institution of Civil Engineering, Structures & Buildings, 2 000,140(2):73-83.
[4] Building Code Requirements for Structural Concrete (ACI 318-08) and Commentary. American Concrete Institute, Farmington Hills, MI 2008.
[5]王志军,柏洁,高巧玲,白绍良.钢筋混凝土梁-墙直交弯矩传递比例分析[J].建筑结构学报.(在录).
[6]杨华,钱稼茹,赵作周.钢筋混凝土梁-墙平面外连接节点试验[J].建筑结构学报.2005.8.
[7]杨华.钢筋混凝土梁-墙平面外连接节点抗震性能研究[D].清华大学硕士论文. 2004.6.
[8]艾侠.高层建筑的平面外墙梁节点研究[D].同济大学硕士学位论文.2004.4.
[9]朱祖敬.钢筋混凝土梁-薄墙正交节点试验研究[D].重庆大学硕士学位论文.2006.12.
[10]陈颖芳.带明梁的钢筋混凝土墙-梁直交节点试验研究[D].重庆大学硕士学位论文.2007.10.
[11]王志浩,黄才广,钱稼茹.强墙弱梁型钢筋混凝土梁-墙平面外连接节点试验[J].建筑结构学报.2008.12.
[12] LARRY A J, JAMES O J. The Influence of Short Embedment and Close Spacing on ,the Strength of Hooked Bar Anchorages[R]. PMFSEL Report No.81-2. 1981.
[13]中国建筑科学研究院建筑结构研究所.《钢筋机械锚固技术与性能研究》课题验收资料.2007.2.
[14]汪洪,徐有邻,史志华.钢筋机械锚固性能的试验研究[J].工业建筑.1991.11.
[15]徐有邻.各类钢筋粘结锚固性能的分析比较[J].福州大学学报自然科学版.1996. 9.
[16]徐有邻,沈文都,汪洪.钢筋砼粘结锚固性能的试验研究[J].建筑结构学报.1994.6
[17]吴广彬,李智斌,刘永颐.带锚固板钢筋的机械锚固性能试验及其最新研究成果[J],建筑科学.2007.11.
[18]李智斌,吴广彬,王依群.带锚固板钢筋机械锚固性能研究进展及趋势[J],建筑科学.2008.5.
[19] Lee,Hung-Jen;National Yunlin U of Sci-Tech,Construction Engineering, and Yu, Si-Ying ;Wei-Sheng Structure Engineering Office Cyclic response of eccentric beam-column connections with mechanical anchorage[J].ACI Structural and Materials Journals.2007.9.
[20] Thompson, M.K., Jirsa, J.O., Breen, J.E., and Klingner, R.E., Anchorage Behavior of Headed Reinforcement: Literature Review, Center for Transportation Research Report 1855-1, Austin, Texas, May 2002.
[21] Thompson, M.K., Young, M.J., Jirsa, J.O., Breen, J.E., and Klingner, R.E., Anchorage Reinforcement in CCT Nodes, Center for Transportation Research Report 1855-2, Austin, Texas, May 2002.
[22] Thompson, M.K., Ledesma, A.L, Jirsa, J.O., Breen, J.E., and Klingner, R.E., Anchorage Behavior of Head Reinforcement Part A: Lap Splices Part B: Design Provisions and Summary, Center for Transportation Research Report 1855-3, Austin, Texas, May 2002 .
[23] AASHTO LRFD Bridge Design Specifications,2nd ed.,American Association of State Highway and Transportation Officials,DC,1998.
[24] CSA Standard CAN3-A23.3-94,Design of Concrete Structures for Buildings with Explanatory Notes,Canadian Standards Association,Rexdale,Ontario,1994.
[25]过镇海,时旭东.钢筋混凝土原理和分析[M],清华大学出版社,2006.
[2]中华人民共和国行业标准.JGJ3-2002,J186-2002.高层建筑混凝土结构技术规程[M].北京.中国建筑工业出版社.2002.
[3] KWAN A K H, CHAN W T. Out-of-plane beam wall joints in tall building structures [J]. Proceedings of the Institution of Civil Engineering, Structures & Buildings, 2 000,140(2):73-83.
[4] Building Code Requirements for Structural Concrete (ACI 318-08) and Commentary. American Concrete Institute, Farmington Hills, MI 2008.
[5]王志军,柏洁,高巧玲,白绍良.钢筋混凝土梁-墙直交弯矩传递比例分析[J].建筑结构学报.(在录).
[6]杨华,钱稼茹,赵作周.钢筋混凝土梁-墙平面外连接节点试验[J].建筑结构学报.2005.8.
[7]杨华.钢筋混凝土梁-墙平面外连接节点抗震性能研究[D].清华大学硕士论文. 2004.6.
[8]艾侠.高层建筑的平面外墙梁节点研究[D].同济大学硕士学位论文.2004.4.
[9]朱祖敬.钢筋混凝土梁-薄墙正交节点试验研究[D].重庆大学硕士学位论文.2006.12.
[10]陈颖芳.带明梁的钢筋混凝土墙-梁直交节点试验研究[D].重庆大学硕士学位论文.2007.10.
[11]王志浩,黄才广,钱稼茹.强墙弱梁型钢筋混凝土梁-墙平面外连接节点试验[J].建筑结构学报.2008.12.
[12] LARRY A J, JAMES O J. The Influence of Short Embedment and Close Spacing on ,the Strength of Hooked Bar Anchorages[R]. PMFSEL Report No.81-2. 1981.
[13]中国建筑科学研究院建筑结构研究所.《钢筋机械锚固技术与性能研究》课题验收资料.2007.2.
[14]汪洪,徐有邻,史志华.钢筋机械锚固性能的试验研究[J].工业建筑.1991.11.
[15]徐有邻.各类钢筋粘结锚固性能的分析比较[J].福州大学学报自然科学版.1996. 9.
[16]徐有邻,沈文都,汪洪.钢筋砼粘结锚固性能的试验研究[J].建筑结构学报.1994.6
[17]吴广彬,李智斌,刘永颐.带锚固板钢筋的机械锚固性能试验及其最新研究成果[J],建筑科学.2007.11.
[18]李智斌,吴广彬,王依群.带锚固板钢筋机械锚固性能研究进展及趋势[J],建筑科学.2008.5.
[19] Lee,Hung-Jen;National Yunlin U of Sci-Tech,Construction Engineering, and Yu, Si-Ying ;Wei-Sheng Structure Engineering Office Cyclic response of eccentric beam-column connections with mechanical anchorage[J].ACI Structural and Materials Journals.2007.9.
[20] Thompson, M.K., Jirsa, J.O., Breen, J.E., and Klingner, R.E., Anchorage Behavior of Headed Reinforcement: Literature Review, Center for Transportation Research Report 1855-1, Austin, Texas, May 2002.
[21] Thompson, M.K., Young, M.J., Jirsa, J.O., Breen, J.E., and Klingner, R.E., Anchorage Reinforcement in CCT Nodes, Center for Transportation Research Report 1855-2, Austin, Texas, May 2002.
[22] Thompson, M.K., Ledesma, A.L, Jirsa, J.O., Breen, J.E., and Klingner, R.E., Anchorage Behavior of Head Reinforcement Part A: Lap Splices Part B: Design Provisions and Summary, Center for Transportation Research Report 1855-3, Austin, Texas, May 2002 .
[23] AASHTO LRFD Bridge Design Specifications,2nd ed.,American Association of State Highway and Transportation Officials,DC,1998.
[24] CSA Standard CAN3-A23.3-94,Design of Concrete Structures for Buildings with Explanatory Notes,Canadian Standards Association,Rexdale,Ontario,1994.
[25]过镇海,时旭东.钢筋混凝土原理和分析[M],清华大学出版社,2006.