双向地震作用下我国“强柱弱梁”措施的有效性评估
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摘要
以往研究柱端弯矩增大系数时一般基于平面分析模型,双向水平地震作用对框架"强柱弱梁"屈服机制的影响未引起重视。严格按中国规范设计出5个不同地震烈度分区的规则空间框架,在OpenSees平台上,采用基于柔度法的纤维模型从而更加真实地模拟柱在双向弯曲和变化轴力作用下的非线性反应,对五个框架进行了罕遇地震下的非线性反应分析。结果表明,7度0.1g区三级抗震空间框架形成了柱铰为主的混合耗能机制,7度0.15g区三级抗震空间框架少量楼层发生了层侧移反应,8度0.2g区、0.3g区二级抗震空间框架均是部分楼层出现明显层侧移反应的典型柱铰机制,9度0.4g区一级抗震空间框架则形成了梁铰、柱铰均较严重的梁柱铰混合机制。五个空间框架在双向地震下的塑性铰分布特征均比相应平面框架更不利。我国不同烈度区、不同抗震等级的空间框架结构在罕遇地震下形成了不同的的塑性铰耗能机制。
Plane analysis model is commonly applied in the study of the moment amplification factor of columns, and the effect of bi-directional horizontal seismic actions on strong column-weak beam yielding mechanism has not been considered seriously. Five regular reinforced concrete 3-D spatial frames were designed strictly according to the Chinese code for different seismic fortification intensities. Based on the OpenSees framework, flexibility method based fiber model was adopted to simulate the nonlinear responses of the columns under biaxial bending and varying axial forces. Nonlinear dynamic response analyses of the five frames under rare earthquake excitations were carried out. The results showed that the spatial frame of the 3rd seismic grade at 7-earthquake intensity 0.1g-region formed a column hinge dominated mechanism, the spatial frame of the 3rd seismic grade at 7-earthquake intensity 0.15g-region tended to develop story side-sway mechanism at a few floors, and the spatial frame of the 2nd seismic grade at 8-earthquake intensity 0.2g-region and 0.3g-region all formed typical column hinge mechanism with story side-sway mechanism occurred at some floors, while the spatial frame of the1st seismic grade at 9-earthquake intensity 0.4g-region developed a column-beam mixed hinge mechanism with severe column hinges and beam hinges. The plastic hinge distributions of the five spatial frames under bi-directional horizontal seismic actions were worse than that of the corresponding plane frames. The plastic hinge energy-dissipating mechanism of the spatial frames in different earthquake intensity regions and different seismic grades were different under rare earthquake excitations.
Plane analysis model is commonly applied in the study of the moment amplification factor of columns, and the effect of bi-directional horizontal seismic actions on strong column-weak beam yielding mechanism has not been considered seriously. Five regular reinforced concrete 3-D spatial frames were designed strictly according to the Chinese code for different seismic fortification intensities. Based on the OpenSees framework, flexibility method based fiber model was adopted to simulate the nonlinear responses of the columns under biaxial bending and varying axial forces. Nonlinear dynamic response analyses of the five frames under rare earthquake excitations were carried out. The results showed that the spatial frame of the 3rd seismic grade at 7-earthquake intensity 0.1g-region formed a column hinge dominated mechanism, the spatial frame of the 3rd seismic grade at 7-earthquake intensity 0.15g-region tended to develop story side-sway mechanism at a few floors, and the spatial frame of the 2nd seismic grade at 8-earthquake intensity 0.2g-region and 0.3g-region all formed typical column hinge mechanism with story side-sway mechanism occurred at some floors, while the spatial frame of the1st seismic grade at 9-earthquake intensity 0.4g-region developed a column-beam mixed hinge mechanism with severe column hinges and beam hinges. The plastic hinge distributions of the five spatial frames under bi-directional horizontal seismic actions were worse than that of the corresponding plane frames. The plastic hinge energy-dissipating mechanism of the spatial frames in different earthquake intensity regions and different seismic grades were different under rare earthquake excitations.
引文
[1]王亚勇.汶川地震建筑震害启示——抗震概念设计[J].建筑结构学报,2008,29(4):20-25(Wang Yayong.Lessons learnt from building damages in the Wenchuan earthquake—seismic concept design of buildings[J].Journal of Building Structures,2008,29(4):20-25(in Chinese))
[2]叶列平,曲哲,马千里,等.从汶川地震中框架结构震害谈“强柱弱梁”屈服机制的实现[J].建筑结构,2008,38(11):52-59(Ye Lieping,Qu Zhe,Ma Qianli,et al.Study on ensuring the strong column-weak beam mechanism for RC frames based on the damage analysis in the Wenchuan earthquake[J].Building Structure,2008,38(11):52-59(in Chinese))
[3]邱法维,李文峰,潘鹏,等.钢筋混凝土柱的双向拟动力静力试验研究[J].建筑结构学报,2001,22(5):26-31(Qiu Fawei,Li Wenfeng,Pan Peng,et al.Quasi-static test research of reinforced concrete column under biaxial loading[J].Journal of Building Structures,2001,22(5):26-31(in Chinese))
[4]杨红,王建辉,白绍良.双向地震作用对框架柱端弯矩增大系数的影响分析[J].土木工程学报,2008,41(9):40-47(Yang Hong,Wang Jianhui,Bai Shaoliang.Effect of bi-directional horizontal seismic excitation on the moment amplification factor of columns[J].China Civil Engineering Journal,2008,41(9):40-47(in Chinese))
[5]杨红,高文生,王志军.空间框架简化为平面模型的抗震分析[J].重庆大学学报:自然科学版,2008,31(11):1267-1272(Yang Hong,Gao Wensheng,Wang Zhijun.The rationality of plane model simplifying three-dimension frame in seismic responses analysis[J].Journal ofChongqing University:Natural Science Edition,2008,31(11):1267-1272(in Chinese))
[6]杨红,韦锋,白绍良,等.柱增强系数取值对钢筋混凝土抗震框架塑性铰机构的控制效果[J].工程力学,2005,22(2):155-161(Yang Hong,Wei Feng,Bai Shaoliang,et al.Effect of moment amplification factors of columns on controlling plastic hinge mechanism of RC frames[J].Engineering Mechanics,2005,22(2):155-161(in Chinese))
[7]韦锋,杨红,白绍良.对我国不同烈度区钢筋混凝土框架现行抗震规定的初步验证[J].重庆建筑大学学报,2001,23(6):1-9(Wei Feng,Yang Hong,Bai Shaoliang.Calibration of seismic provisions for RC frames in different earthquake-intensity regions in China[J].Journal of Chongqing Jianzhu University,2001,23(6):1-9(in Chinese))
[8]刘光明,杨红,邹胜斌,等.基于新规范的钢筋混凝土框架抗震性能评价[J].重庆建筑大学学报,2004,26(1):40-49(Liu Guangming,Yang Hong,Zou Shengbin,et al.Seismic assessment of RC frame structure based on new design codes[J].Journal of Chongqing Jianzhu University,2004,26(1):40-49(in Chinese))
[9]Comite Euro-international du Beton(CEB)task groupⅢ/2.Seismic design of reinforced concrete structures for controlled inelastic response(design concepts)[R].London,UK:Thomas Telford Ltd.,1998
[10]Kelley T E.Some seismic design aspects of multistorey concrete frames[D].Christchurch,New Zealand:University of Canterbury,1974
[11]吴勇,雷汲川,杨红,等.板筋参与梁端负弯矩承载力问题的探讨[J].重庆建筑大学学报,2002,24(3):33-37(Wu Yong,Lei Jichuan,Yang Hong,et al.Discussion on negative flexural strength of beams including slabs[J].Journal of Chongqing Jianzhu University,2002,24(3):33-37(in Chinese))
[12]《汶川地震建筑震害调查与灾后重建分析报告》编委会.汶川地震建筑震害调查与灾后重建分析报吿[M].北京:中国建筑工业出版社,2008
[2]叶列平,曲哲,马千里,等.从汶川地震中框架结构震害谈“强柱弱梁”屈服机制的实现[J].建筑结构,2008,38(11):52-59(Ye Lieping,Qu Zhe,Ma Qianli,et al.Study on ensuring the strong column-weak beam mechanism for RC frames based on the damage analysis in the Wenchuan earthquake[J].Building Structure,2008,38(11):52-59(in Chinese))
[3]邱法维,李文峰,潘鹏,等.钢筋混凝土柱的双向拟动力静力试验研究[J].建筑结构学报,2001,22(5):26-31(Qiu Fawei,Li Wenfeng,Pan Peng,et al.Quasi-static test research of reinforced concrete column under biaxial loading[J].Journal of Building Structures,2001,22(5):26-31(in Chinese))
[4]杨红,王建辉,白绍良.双向地震作用对框架柱端弯矩增大系数的影响分析[J].土木工程学报,2008,41(9):40-47(Yang Hong,Wang Jianhui,Bai Shaoliang.Effect of bi-directional horizontal seismic excitation on the moment amplification factor of columns[J].China Civil Engineering Journal,2008,41(9):40-47(in Chinese))
[5]杨红,高文生,王志军.空间框架简化为平面模型的抗震分析[J].重庆大学学报:自然科学版,2008,31(11):1267-1272(Yang Hong,Gao Wensheng,Wang Zhijun.The rationality of plane model simplifying three-dimension frame in seismic responses analysis[J].Journal ofChongqing University:Natural Science Edition,2008,31(11):1267-1272(in Chinese))
[6]杨红,韦锋,白绍良,等.柱增强系数取值对钢筋混凝土抗震框架塑性铰机构的控制效果[J].工程力学,2005,22(2):155-161(Yang Hong,Wei Feng,Bai Shaoliang,et al.Effect of moment amplification factors of columns on controlling plastic hinge mechanism of RC frames[J].Engineering Mechanics,2005,22(2):155-161(in Chinese))
[7]韦锋,杨红,白绍良.对我国不同烈度区钢筋混凝土框架现行抗震规定的初步验证[J].重庆建筑大学学报,2001,23(6):1-9(Wei Feng,Yang Hong,Bai Shaoliang.Calibration of seismic provisions for RC frames in different earthquake-intensity regions in China[J].Journal of Chongqing Jianzhu University,2001,23(6):1-9(in Chinese))
[8]刘光明,杨红,邹胜斌,等.基于新规范的钢筋混凝土框架抗震性能评价[J].重庆建筑大学学报,2004,26(1):40-49(Liu Guangming,Yang Hong,Zou Shengbin,et al.Seismic assessment of RC frame structure based on new design codes[J].Journal of Chongqing Jianzhu University,2004,26(1):40-49(in Chinese))
[9]Comite Euro-international du Beton(CEB)task groupⅢ/2.Seismic design of reinforced concrete structures for controlled inelastic response(design concepts)[R].London,UK:Thomas Telford Ltd.,1998
[10]Kelley T E.Some seismic design aspects of multistorey concrete frames[D].Christchurch,New Zealand:University of Canterbury,1974
[11]吴勇,雷汲川,杨红,等.板筋参与梁端负弯矩承载力问题的探讨[J].重庆建筑大学学报,2002,24(3):33-37(Wu Yong,Lei Jichuan,Yang Hong,et al.Discussion on negative flexural strength of beams including slabs[J].Journal of Chongqing Jianzhu University,2002,24(3):33-37(in Chinese))
[12]《汶川地震建筑震害调查与灾后重建分析报告》编委会.汶川地震建筑震害调查与灾后重建分析报吿[M].北京:中国建筑工业出版社,2008
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