钢筋混凝土桥墩开裂刚度理论与试验研究
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摘要
我国是世界上地震活动最强烈的国家之一,地震灾害历来是我国最大的自然灾害之一。2008年5月12日14点28分在我国四川省发生举世瞩目的汶川大地震,据我国强震观测台站记录资料显示,当时最大峰值加速度达到957.7gal,大部分房屋和其他建筑物倒塌,震区桥梁遭到了不同程度的破坏,交通被迫中断,给抗震救援工作带来了极大的困难。桥梁在抗震救灾生命线中起着重要作用,因此桥梁抗震设计十分重要;而桥墩作为桥梁结构的重要部分,是抗震设计的主要计算内容之一。
在进行公路桥梁延性抗震设计分析时,延性构件(桥墩)的抗弯刚度应按其有效截面抗弯刚度计算。目前国内外对于钢筋混凝土桥墩开裂后的抗弯刚度计算,多使用回归试验数据、提出经验公式以及使用有限元软件或弯矩-曲率分析软件计算数值解等方法。而相关的理论研究工作较为薄弱,使用基本的力学理论对钢筋混凝土桥墩开裂刚度进行分析的方法和文献相对较少。在弹性受力范围内,本文以双筋矩形混凝土墩柱构件为对象,从基本的力学概念出发,进一步讨论了构件受弯开裂时各截面受压区高度与刚度的分布特性;并通过相关分析软件和试验的方式加以比较和分析。本文完成的主要工作如下:
(1)运用“三段式”线性刚度形式简化划分了墩柱各截面抗弯刚度沿墩身方向的分布,并利用该方法提出了墩柱三个刚度段各自的截面抗弯刚度计算公式;
(2)通过对钢筋混凝土桥墩开裂截面形心轴位置的计算,探讨和分析了轴压力因形心轴偏移而产生的附加弯矩作用,并就墩柱所受外力弯矩进行总结;
(3)采用基本的力学方法,借助相关编程软件,以实际算例计算了桥墩弯曲位移和整体刚度,并与相关分析软件进行了比较分析;
(4)通过墩柱开裂抗弯刚度的试验研究与本文理论计算结果进行对比分析,归纳总结了钢筋混凝土桥墩开裂刚度的变化趋势,为墩柱整体开裂刚度计算公式的提出提供了参考。
As one of the most violented earthquake countrys, earthquake disaster is one of serious natural disasters in China. At 2:28 pm, May 12th, 2008, the WenChuan earthquake happended in SiChuan province which took a big challenge to the seismic engineering. Accoring to the earthquake observing station, the biggest acceleration was 957.7gal at that time, a large of houses and other building were collapse, bridges in disaster area was broken, and transportation was cut off, which made the seismic rescuing much more difficult. As we all know, bridge takes big effect in the lifeline of relief work, so the seismic design of bridgeis very important; as one major load bearing part of bridge, the pier seismic design should be pay more attention to.
In the ductile seismic design analysis of highway bridge, flexural stiffness of ductile structure(pier) should consider as the effective cross-section stiffness. At present, it often compute the cracked stiffness according to test data, empirical formula and finite element software. The research on cracking stiffness of pier is hardly found especially in the theoretical way.
In the elastic range, based on the concepts of the mechanics, this paper, researched on the bi-reinforced rectangular concrete column, discussd the depth of compression zone and properties of the stiffness distribution, compared and analysed the results with the help of software and test. The work of this paper are listed as follow:
1. Using "three-phase" linear stiffness, a simplly division of the cross-section stiffness distribution has been presented; meanwhile, a flexural stiffness formula for three stiffness phase has been suggested;
2. By way of neutral axis counting of cracking cross-section for reinforce concrete column, the paper researched additional moment due to neutral axis deviation, and summarized the moment of physical force acting on column.
3. Using the basic mechanics method, with the help of programme software, this paper counted and summarized flexural displacement and stiffness of column base on a example, and compared with the analytic software.
4. Compared and analyzed with the cracking stiffness test of column. the paper summarized the variation trend of cracked stiffness of reinforce concrete column to make a cross-reference for the whole stiffness formula of column.
在进行公路桥梁延性抗震设计分析时,延性构件(桥墩)的抗弯刚度应按其有效截面抗弯刚度计算。目前国内外对于钢筋混凝土桥墩开裂后的抗弯刚度计算,多使用回归试验数据、提出经验公式以及使用有限元软件或弯矩-曲率分析软件计算数值解等方法。而相关的理论研究工作较为薄弱,使用基本的力学理论对钢筋混凝土桥墩开裂刚度进行分析的方法和文献相对较少。在弹性受力范围内,本文以双筋矩形混凝土墩柱构件为对象,从基本的力学概念出发,进一步讨论了构件受弯开裂时各截面受压区高度与刚度的分布特性;并通过相关分析软件和试验的方式加以比较和分析。本文完成的主要工作如下:
(1)运用“三段式”线性刚度形式简化划分了墩柱各截面抗弯刚度沿墩身方向的分布,并利用该方法提出了墩柱三个刚度段各自的截面抗弯刚度计算公式;
(2)通过对钢筋混凝土桥墩开裂截面形心轴位置的计算,探讨和分析了轴压力因形心轴偏移而产生的附加弯矩作用,并就墩柱所受外力弯矩进行总结;
(3)采用基本的力学方法,借助相关编程软件,以实际算例计算了桥墩弯曲位移和整体刚度,并与相关分析软件进行了比较分析;
(4)通过墩柱开裂抗弯刚度的试验研究与本文理论计算结果进行对比分析,归纳总结了钢筋混凝土桥墩开裂刚度的变化趋势,为墩柱整体开裂刚度计算公式的提出提供了参考。
As one of the most violented earthquake countrys, earthquake disaster is one of serious natural disasters in China. At 2:28 pm, May 12th, 2008, the WenChuan earthquake happended in SiChuan province which took a big challenge to the seismic engineering. Accoring to the earthquake observing station, the biggest acceleration was 957.7gal at that time, a large of houses and other building were collapse, bridges in disaster area was broken, and transportation was cut off, which made the seismic rescuing much more difficult. As we all know, bridge takes big effect in the lifeline of relief work, so the seismic design of bridgeis very important; as one major load bearing part of bridge, the pier seismic design should be pay more attention to.
In the ductile seismic design analysis of highway bridge, flexural stiffness of ductile structure(pier) should consider as the effective cross-section stiffness. At present, it often compute the cracked stiffness according to test data, empirical formula and finite element software. The research on cracking stiffness of pier is hardly found especially in the theoretical way.
In the elastic range, based on the concepts of the mechanics, this paper, researched on the bi-reinforced rectangular concrete column, discussd the depth of compression zone and properties of the stiffness distribution, compared and analysed the results with the help of software and test. The work of this paper are listed as follow:
1. Using "three-phase" linear stiffness, a simplly division of the cross-section stiffness distribution has been presented; meanwhile, a flexural stiffness formula for three stiffness phase has been suggested;
2. By way of neutral axis counting of cracking cross-section for reinforce concrete column, the paper researched additional moment due to neutral axis deviation, and summarized the moment of physical force acting on column.
3. Using the basic mechanics method, with the help of programme software, this paper counted and summarized flexural displacement and stiffness of column base on a example, and compared with the analytic software.
4. Compared and analyzed with the cracking stiffness test of column. the paper summarized the variation trend of cracked stiffness of reinforce concrete column to make a cross-reference for the whole stiffness formula of column.
引文
[1]卢寿德,李小军.汶川8.0级地震未校正加速度记录:中国强震记录汇报.地震出版社.2008
[2]中国地震局.GB 18306-2001.中国地震动参数区划图.2001
[3]范立础,卓卫东.桥梁延性抗震设计.人民交通出版社.2001
[4]中华人民共和国交通部.JTJ 004-89.公路工程抗震设计规范.1989
[5] American Association of state Highway and transportation officials.AASHTO LRFD Bridge Design Specificitions.SI Unite Second Edition.1998
[6] CEN.Eurcode8-Design Provisions for Earthquake Resistance of Structures, Part2: Bridges. Committee European De Normalization(CEN) .1998
[7]范立础.桥梁抗震.同济大学出版社.1996
[8] California Department of Transportation (CALTRANS). Seismic Design Criteria,Version1.4. California.2006
[9]日本道路协会.道路桥示方书?同解说,V耐震设计篇.东京.平成14年3月
[10]重庆交通科研设计院. JTG/T B02-01-2008.公路桥梁抗震设计细则.北京.人民交通出版社.2008
[11]钢筋混凝土小偏心受压构件的曲率、刚度和杆端转角.同济大学科学技术情报组编印.1973-4
[12]南京工学院工民建专业刚度裂缝科研小组.钢筋混凝土构件刚度和裂缝的计算.南京工学院学报土木工程专集. 1979
[13]南京工学院第五系.钢筋混凝土偏心受力构件刚度计算初探.1977
[14]丁大钧等.钢筋混凝土矩形截面偏心受压构件刚度裂缝的试验研究.南京工学院.1979-9
[15]四川省建筑科学研究所.钢筋混凝土屋架考虑非弹性的试验分析及刚度计算.1979-12
[16]郭磊、李建中、范立础.桥梁结构抗震设计中截面刚度的取值分析.同济大学学报.2004
[17]李永哲、阎贵平等.钢筋混凝土桥墩刚度和强度折减系数确定.世界地震工程.2005
[18] Mehanny,S.S.F.Modeling and Assessment of Seismic Performance of Composite Frames with Reinforced Concrete Columns and Steel Beams. Dissertation. Department of Civil and Environmental Engineering, Stanford University.1999
[19] Panagiotakos, T. B. and Fardis, M. N.Deformations of Reinforced Concrete at Yielding and Ultimate.ACI Structural Journal.2001.Vol. 98, No. 2.135-147
[20] K.J. Elwood,M.O. Eberhard. Effective Stiffness of Reinforced Concrete Columns.PEER Research Digest 2006-1.2006
[21] M.J.N.Priestley,G.M.Calvi. Displacement-Based Seismic Design of_Structures.IUSS.2007
[22] Curt B. Haselton, Abbie B. Liel, Sarah Taylor Lange, and Gregory g.Beam-Column Element Model Calibrated for Predicting Flexural Response Leading to Global Collapse of RC Frame Buildings.PEER Research Report.University of California-Berkeley.May 2008
[23] Micheal P.Berry, Dawn E.Lehman, Laura N.Lowes.Lumped-Plasticity Models for Performance Simulation of bridge columns.ACI Structure Journal.2008.V.105,No.3.270-279
[24] American Society of Civil Engineers.FEMA 356: Prestandard and Commentary for the Seismic Rehabilitation of Buildings.Federal Emergency Management Agency.Washington.- 2000
[25]何万钟,何秀杰.中国土木建筑百科辞典.中国建筑工业出版社.1999
[26]邢富冲.一元三次方程求解新探.中央民族大学学报(自然科学版).2003.7
[27]苗宇.钢筋混凝土矩形桥墩开裂刚度理论初探.重庆交通大学硕士论文.2009.6
[28]樊友景等.压弯构件的附加弯矩分析.郑州大学学报(理学版).2007.9
[29]孙哗青等.对压弯构件附加弯矩的研究.力学与实践.2004年第26卷第4期
[30]铁摩辛柯.弹性稳定理论.科学出版社.1965
[31]高剑飞.OpenSees:一个专用于土木工程的分析软件.四川水利.2007
[32]李睿,董明.考虑P-Δ效应的高墩抗震计算.云南工业大学学报.1999
[33] Mark Aschheim. The representation of P-Δeffects using yield point spectra.Engineering Structures.2003
[34] Asadollah Esmaeily-Gh, Yan Xiao. Seismic Behavior of Bridge Columns Subjected to Various Loading Patterns.PEER report.2002
[35] Dawn E.Lehman. Seismic Performance of Well-Confined Concrete Bridge Columns. PEER report.1998
[36] Wayne A. Brown. Bar Buckling in Reinforced Concrete Bridge Columns.PEER report 2007
[37] Anthony J. Calderone. Behavior of Reinforced Concrete Bridge Columns Having Varying Aspect Ratios and Varying Lengths of Confinement. PEER report.2000.8
[38]中华人民共和国建设部.GB/T 50080-2002,普通混凝土拌合物性能试验方法标准.2003
[39]中华人民共和国国家质量监督检验检疫总局,GB/T 228-2002,金属材料室温拉伸试验方法,2002
[2]中国地震局.GB 18306-2001.中国地震动参数区划图.2001
[3]范立础,卓卫东.桥梁延性抗震设计.人民交通出版社.2001
[4]中华人民共和国交通部.JTJ 004-89.公路工程抗震设计规范.1989
[5] American Association of state Highway and transportation officials.AASHTO LRFD Bridge Design Specificitions.SI Unite Second Edition.1998
[6] CEN.Eurcode8-Design Provisions for Earthquake Resistance of Structures, Part2: Bridges. Committee European De Normalization(CEN) .1998
[7]范立础.桥梁抗震.同济大学出版社.1996
[8] California Department of Transportation (CALTRANS). Seismic Design Criteria,Version1.4. California.2006
[9]日本道路协会.道路桥示方书?同解说,V耐震设计篇.东京.平成14年3月
[10]重庆交通科研设计院. JTG/T B02-01-2008.公路桥梁抗震设计细则.北京.人民交通出版社.2008
[11]钢筋混凝土小偏心受压构件的曲率、刚度和杆端转角.同济大学科学技术情报组编印.1973-4
[12]南京工学院工民建专业刚度裂缝科研小组.钢筋混凝土构件刚度和裂缝的计算.南京工学院学报土木工程专集. 1979
[13]南京工学院第五系.钢筋混凝土偏心受力构件刚度计算初探.1977
[14]丁大钧等.钢筋混凝土矩形截面偏心受压构件刚度裂缝的试验研究.南京工学院.1979-9
[15]四川省建筑科学研究所.钢筋混凝土屋架考虑非弹性的试验分析及刚度计算.1979-12
[16]郭磊、李建中、范立础.桥梁结构抗震设计中截面刚度的取值分析.同济大学学报.2004
[17]李永哲、阎贵平等.钢筋混凝土桥墩刚度和强度折减系数确定.世界地震工程.2005
[18] Mehanny,S.S.F.Modeling and Assessment of Seismic Performance of Composite Frames with Reinforced Concrete Columns and Steel Beams. Dissertation. Department of Civil and Environmental Engineering, Stanford University.1999
[19] Panagiotakos, T. B. and Fardis, M. N.Deformations of Reinforced Concrete at Yielding and Ultimate.ACI Structural Journal.2001.Vol. 98, No. 2.135-147
[20] K.J. Elwood,M.O. Eberhard. Effective Stiffness of Reinforced Concrete Columns.PEER Research Digest 2006-1.2006
[21] M.J.N.Priestley,G.M.Calvi. Displacement-Based Seismic Design of_Structures.IUSS.2007
[22] Curt B. Haselton, Abbie B. Liel, Sarah Taylor Lange, and Gregory g.Beam-Column Element Model Calibrated for Predicting Flexural Response Leading to Global Collapse of RC Frame Buildings.PEER Research Report.University of California-Berkeley.May 2008
[23] Micheal P.Berry, Dawn E.Lehman, Laura N.Lowes.Lumped-Plasticity Models for Performance Simulation of bridge columns.ACI Structure Journal.2008.V.105,No.3.270-279
[24] American Society of Civil Engineers.FEMA 356: Prestandard and Commentary for the Seismic Rehabilitation of Buildings.Federal Emergency Management Agency.Washington.- 2000
[25]何万钟,何秀杰.中国土木建筑百科辞典.中国建筑工业出版社.1999
[26]邢富冲.一元三次方程求解新探.中央民族大学学报(自然科学版).2003.7
[27]苗宇.钢筋混凝土矩形桥墩开裂刚度理论初探.重庆交通大学硕士论文.2009.6
[28]樊友景等.压弯构件的附加弯矩分析.郑州大学学报(理学版).2007.9
[29]孙哗青等.对压弯构件附加弯矩的研究.力学与实践.2004年第26卷第4期
[30]铁摩辛柯.弹性稳定理论.科学出版社.1965
[31]高剑飞.OpenSees:一个专用于土木工程的分析软件.四川水利.2007
[32]李睿,董明.考虑P-Δ效应的高墩抗震计算.云南工业大学学报.1999
[33] Mark Aschheim. The representation of P-Δeffects using yield point spectra.Engineering Structures.2003
[34] Asadollah Esmaeily-Gh, Yan Xiao. Seismic Behavior of Bridge Columns Subjected to Various Loading Patterns.PEER report.2002
[35] Dawn E.Lehman. Seismic Performance of Well-Confined Concrete Bridge Columns. PEER report.1998
[36] Wayne A. Brown. Bar Buckling in Reinforced Concrete Bridge Columns.PEER report 2007
[37] Anthony J. Calderone. Behavior of Reinforced Concrete Bridge Columns Having Varying Aspect Ratios and Varying Lengths of Confinement. PEER report.2000.8
[38]中华人民共和国建设部.GB/T 50080-2002,普通混凝土拌合物性能试验方法标准.2003
[39]中华人民共和国国家质量监督检验检疫总局,GB/T 228-2002,金属材料室温拉伸试验方法,2002