设计参数对RC框架结构抗倒塌性能的影响分析
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摘要
结构地震响应输出的强随机性除了主要受地震动非平稳随机激励影响以外,结构自身材料强度、构件尺寸及组合方式等不确定因素的影响同样不容忽视。因此,本文基于课题组完成的RC平面框架低周反复加载试验,以轴压比、梁柱线刚度比、混凝土强度及钢筋强度为变量,对拟建的16榀有限元数值模型进行了抗震性能分析和动力弹塑性时程分析,给出了不同性能水平下结构最大层间位移角的变化范围,研究了轴压比、梁柱线刚度比变化对RC框架结构抗倒塌能力的影响,得到主要结论如下:轴压比增大有利于提高结构的承载力及耗能能力,但延性变形能力会明显下降;降低梁柱线刚度比有利于提高结构的抗震性能;RC框架结构最大层间位移角达到1/620、1/340、1/120、1/30时,可分别作为"基本完好(OP)"、"立即使用(IO)"、"生命安全(LS)"、"防止倒塌(CP)"四个性能水平点的限值;轴压比和梁柱线刚度比的增大会降低RC框架结构的抗倒塌能力、增加结构发生倒塌失效破坏的概率。
The strong randomness of the seismic response output of structures is not only affected by the non-stationary random excitation of ground motion, but also affected by uncertainties such as structural strength, component size and combination. Therefore, the seismic performance analysis and dynamic elastoplastic time history analysis of proposed nineteen finite element models are carried out based on the low-cycle repeated loading test of the RC plane frame, and the axial compression ratio, beam-to-column stiffness ratio, concrete strength and steel strength are variables. The variation range of the maximum interlayer displacement angle of structures under different performance levels is given. The effects of axial compression ratio and beam-to-column stiffness ratio on the collapse resistance of RC frame structures are studied. The main conclusions are as follows: The increase of axial compression ratio is beneficial to improve the bearing capacity and energy dissipation capacity of structures, but the ductility deformation capacity will be significantly reduced. Reducing the beam-to-column stiffness ratio is beneficial to improving the seismic performance of the structure. The points that the maximum interlayer displacement angle of the RC frame structure reaches 1/620, 1/340, 1/120, and 1/30 can be used as the limit of four performance level of "Operational(OP)", "Immediate Occupancy(IO)", "Life Safety(LS)" and "Collapse Prevention(CP)". The increase of axial compression ratio and beam-to-column stiffness ratio will reduce the collapse resistance performance of RC frame structures and increase the collapse failure probability.
The strong randomness of the seismic response output of structures is not only affected by the non-stationary random excitation of ground motion, but also affected by uncertainties such as structural strength, component size and combination. Therefore, the seismic performance analysis and dynamic elastoplastic time history analysis of proposed nineteen finite element models are carried out based on the low-cycle repeated loading test of the RC plane frame, and the axial compression ratio, beam-to-column stiffness ratio, concrete strength and steel strength are variables. The variation range of the maximum interlayer displacement angle of structures under different performance levels is given. The effects of axial compression ratio and beam-to-column stiffness ratio on the collapse resistance of RC frame structures are studied. The main conclusions are as follows: The increase of axial compression ratio is beneficial to improve the bearing capacity and energy dissipation capacity of structures, but the ductility deformation capacity will be significantly reduced. Reducing the beam-to-column stiffness ratio is beneficial to improving the seismic performance of the structure. The points that the maximum interlayer displacement angle of the RC frame structure reaches 1/620, 1/340, 1/120, and 1/30 can be used as the limit of four performance level of "Operational(OP)", "Immediate Occupancy(IO)", "Life Safety(LS)" and "Collapse Prevention(CP)". The increase of axial compression ratio and beam-to-column stiffness ratio will reduce the collapse resistance performance of RC frame structures and increase the collapse failure probability.
引文
[1] 清华大学土木结构组,西南交通大学土木结构组,北京交通大学土木结构组.汶川地震建筑震害分析[J].建筑结构学报,2008,29(4):1-9.Civil and Structural Group of Tsinghua University,Xinan Jiaotong University,Beijing Jiaotong University.Analysis on seismic damage of building in the Wenchuan earthquake[J].Journal of Building Structures,2008,29(4):1-9.(in Chinese)
[2] 吕大刚,宋鹏彦,于晓辉,等.土木工程结构抗震可靠度理论的研究与发展[C]//第二届结构工程新进展国际论坛,大连:2008:775-787.LV Dagang,SO Pengyan,YU Xiaohui,et al.Research and developments of seismic reliability theory of civil engineering structures[C]//Second International Forum on New Progress of Structural Engineering,Dalian:2008:775-787.(in Chinese)
[3] 王亚勇,高孟潭,叶列平,等.基于大震和特大震下倒塌率目标的建筑抗震设计方法研究[J].土木建筑与环境工程,2010,32(S2):291-297.WANG Yayong,GAO Mengtan,YE Lieping,et al.Study on seismic design method of buildings based on collapse rate target under large and extra-large earthquakes[J].Journal of Civil,Architectural and Environmental,2010,32(S2):291-297.(in Chinese)
[4] Liel A B,Haselton C B,Deierlein G G.Seismic collapse safety of reinforced concrete buildings.II:Comparative assessment of nonductile and ductile moment frames[J].Journal of Structural Engineering,2010,137(4):492-502.
[5] Haselton C B,Deierlein G G.Assessing Seismic Collapse Safety of Modern Reinforced Concrete Moment-Frame Buildings [M].Pacific Earthquake Engineering Research Center,2007/08.
[6] GB50010-2010,混凝土结构设计规范[S].北京:中国建筑工业出版社,2010.GB50010-2010,Code for Design of Concrete Structures[S].Beijing:China Architecture & Building Press,2010.(in Chinese)
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[8] 曲哲,叶列平.基于有效累积滞回耗能的钢筋混凝土构件承载力退化模型[J].工程力学 ,2011,28(06):45-51.QU Zhe,YE Lieping.Strength deteriorarion model based on effective hysteretic energy dissipation for RC members under cyclic loading[J].Engineering Mechanics,2011,28(06):45-51.(in Chinese)
[9] Kent D C,Park R.Flexural members with confined concrete[J].ASCE,1971,97(7):1969-1990.
[10] ScottB D,Park R,Priestley M J N.Stress-strain behavior of concrete confined by overlapping hoops at low and high strain rates[J].ACI Journal,1982,79:1327.
[11] 刘伯权,白绍良,徐云中,等.钢筋混凝土柱低周疲劳性能的试验研究[J].地震工程与工程振动,1998,18(4):82-89.LIU Boquan,BAI Shaoliang,XU Yunzhong,et al.Experimental study of low-cyclic behavior of concrete conlumns[J].Earthquake Engineering and Engineering Dynamics.1998,18(4):82-89.(in Chinese)
[12] 刘钦.基于优化原理的框架梁柱合理线刚度比研究[J].河南城建学院学报,2009,18(5):21-22,38.LIU Qin.Study on reasonable line stiffness ratio of framework beam and column based on optimization theory[J].Henan University of Urban Construction,2009,18(5):21-22,38.(in Chinese)
[13] 杨溥,李英民,赖明.结构时程分析法输入地震波的选择控制指标[J].土木工程学报,2000,33(6):33-37.YANG Pu,LI Yingmin,LAI Ming.A new method for selecting inputting waves for time-history analysis[J].China Civil Engineering Journal,2000,33(6):33-37.(in Chinese)
[14] FEMA.Recommended seismic evaluation and upgrade criteria for existing welded steel moment—frame buildings[R].Report No.FEMA-35 1,SAC Joint Venture,Federal Emergency Management Agency,Washington,DC,2000.
[15] FEMA.NEHRP guidelines for seismic rehabilitation of buildings[R].Report No.FEMA-273,SAC Joint Venture,Federal Emergency Management Agency,Washington,DC,1997.
[16] Ghobarah A,Abou-Elfath H,Biddah A.Response-based damage assessment of structures[J].Earthquake Engineering & Structural Dynamics,1999,28(1),79-104.
[2] 吕大刚,宋鹏彦,于晓辉,等.土木工程结构抗震可靠度理论的研究与发展[C]//第二届结构工程新进展国际论坛,大连:2008:775-787.LV Dagang,SO Pengyan,YU Xiaohui,et al.Research and developments of seismic reliability theory of civil engineering structures[C]//Second International Forum on New Progress of Structural Engineering,Dalian:2008:775-787.(in Chinese)
[3] 王亚勇,高孟潭,叶列平,等.基于大震和特大震下倒塌率目标的建筑抗震设计方法研究[J].土木建筑与环境工程,2010,32(S2):291-297.WANG Yayong,GAO Mengtan,YE Lieping,et al.Study on seismic design method of buildings based on collapse rate target under large and extra-large earthquakes[J].Journal of Civil,Architectural and Environmental,2010,32(S2):291-297.(in Chinese)
[4] Liel A B,Haselton C B,Deierlein G G.Seismic collapse safety of reinforced concrete buildings.II:Comparative assessment of nonductile and ductile moment frames[J].Journal of Structural Engineering,2010,137(4):492-502.
[5] Haselton C B,Deierlein G G.Assessing Seismic Collapse Safety of Modern Reinforced Concrete Moment-Frame Buildings [M].Pacific Earthquake Engineering Research Center,2007/08.
[6] GB50010-2010,混凝土结构设计规范[S].北京:中国建筑工业出版社,2010.GB50010-2010,Code for Design of Concrete Structures[S].Beijing:China Architecture & Building Press,2010.(in Chinese)
[7] GB50011-2010,建筑抗震设计规范[S].北京:中国建筑工业出版社,2010.GB50011-2010,Code for Seismic Design of Buildings[S] Beijing:China Architecture & Building Press,2010.(in Chinese)
[8] 曲哲,叶列平.基于有效累积滞回耗能的钢筋混凝土构件承载力退化模型[J].工程力学 ,2011,28(06):45-51.QU Zhe,YE Lieping.Strength deteriorarion model based on effective hysteretic energy dissipation for RC members under cyclic loading[J].Engineering Mechanics,2011,28(06):45-51.(in Chinese)
[9] Kent D C,Park R.Flexural members with confined concrete[J].ASCE,1971,97(7):1969-1990.
[10] ScottB D,Park R,Priestley M J N.Stress-strain behavior of concrete confined by overlapping hoops at low and high strain rates[J].ACI Journal,1982,79:1327.
[11] 刘伯权,白绍良,徐云中,等.钢筋混凝土柱低周疲劳性能的试验研究[J].地震工程与工程振动,1998,18(4):82-89.LIU Boquan,BAI Shaoliang,XU Yunzhong,et al.Experimental study of low-cyclic behavior of concrete conlumns[J].Earthquake Engineering and Engineering Dynamics.1998,18(4):82-89.(in Chinese)
[12] 刘钦.基于优化原理的框架梁柱合理线刚度比研究[J].河南城建学院学报,2009,18(5):21-22,38.LIU Qin.Study on reasonable line stiffness ratio of framework beam and column based on optimization theory[J].Henan University of Urban Construction,2009,18(5):21-22,38.(in Chinese)
[13] 杨溥,李英民,赖明.结构时程分析法输入地震波的选择控制指标[J].土木工程学报,2000,33(6):33-37.YANG Pu,LI Yingmin,LAI Ming.A new method for selecting inputting waves for time-history analysis[J].China Civil Engineering Journal,2000,33(6):33-37.(in Chinese)
[14] FEMA.Recommended seismic evaluation and upgrade criteria for existing welded steel moment—frame buildings[R].Report No.FEMA-35 1,SAC Joint Venture,Federal Emergency Management Agency,Washington,DC,2000.
[15] FEMA.NEHRP guidelines for seismic rehabilitation of buildings[R].Report No.FEMA-273,SAC Joint Venture,Federal Emergency Management Agency,Washington,DC,1997.
[16] Ghobarah A,Abou-Elfath H,Biddah A.Response-based damage assessment of structures[J].Earthquake Engineering & Structural Dynamics,1999,28(1),79-104.