钢筋砼框架倒塌过程中框架梁剪切破坏机理研究
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摘要
如果建筑物的框架柱遭破坏,就可能发生竖向连续倒塌,造成严重的人员伤亡和经济损失,因此如何防止建筑竖向连续倒塌已经成为结构工程研究的重要课题之一。延性是防止建筑竖向倒塌的主要因素之一,所以建筑应避免在弯曲破坏之前发生剪切破坏。
对两端固定的钢筋混凝土梁在1/4跨、1/2跨、3/4跨通过施加荷载的方式来模拟次梁和现浇板传来的荷载,在梁跨中通过自制的自动脱钩器等效为柱的移去来模拟钢筋混凝土框架结构在失去边跨中柱时其上方的钢筋混凝土框架梁在跨度成倍时的情形,研究钢筋混凝土框架柱下支撑移去后框架梁的动力响应和剪切破坏机理,研究结果表明:梁KJL01、KJL02的破坏形态为弯曲破坏,梁KJL-2、KJL-3、KJL-4的破坏形态为剪切破坏。通过计算得到弯曲DCR值在1.7～1.9之间,剪切DCR值不大于1.2。当梁发生剪切破坏时,拱效应不能充分发挥,使得梁的极限承载力降低,所以在建筑结构抗倒塌设计时必须按照“强剪弱弯”的原则进行抗剪设计。
对无阻尼单自由度弹塑性系统动力响应进行分析,分析结果表明:弹塑性结构体系的弯曲DCR的取值与延性系数β有关,当β= 2时,DCR取值为0.75。对突加荷载作用下单自由度有阻尼系统在弹性阶段的动力响应进行分析,得到系统达到最大位移的时间与升载时间无关,只取决于结构的自振周期T,并且系统进入塑性阶段而不破坏的最短时间为T/4。
If the frame column is destroyed, progressive collapse may happen in the building, causing serious casualties and economic losses, so how to prevent the progressive collapse has become one of important issues for structure Engineering. Ductility is one of the main factors to prevent the vertical progressive collapse of the building, so the building should avoid shear failure prior to bending failure.
The load coming from the secondary beam and cast-in-place plate in 1/4 span, 1/2 span, 3/4 span by the imposition of weight on the reinforced concrete beams fixed at both ends has been simulated, and the case that reinforced concrete frame beams doubled has been simulated when reinforced concrete frame beam loses mid column in the side at the midspan by automatic detacher. It studies dynamic response and shear failure mechanism when reinforced concrete frame column damaged suddenly, and experimental results indicate that: damage patterns of beams KJL01, KJL02 are bending failure, and damage patterns of beams KJL-2, KJL-3, KJL-4 are shear failure. The values of bending DCR are between 1.7 and 1.9, and shear DCR are not more than 1.2. When the beam occurs shear failure, the arch effect can’t bring into full play, and consequently makes the ultimate capacity of beam lowering, so the building must configurate reinforced in the building design to resist progressive collapse in accordance with "strong shear weak bending".
Dynamic response of single degree of freedom without damping elastic-plastic system has been analysed, the results show that: the value of bending DCR of elastic-plastic system has something to do with the ductility factorβ, whenβ=2 and the value of DCR is 0.75. Dynamic response of single degree of freedom elastic damping system has been analysised to find that the time to the maximum displacement has nothing with loading time only depending on the natural cycle T of the building, the shortest time when the system goes into Plastic stage and without undermining is T/4.
对两端固定的钢筋混凝土梁在1/4跨、1/2跨、3/4跨通过施加荷载的方式来模拟次梁和现浇板传来的荷载,在梁跨中通过自制的自动脱钩器等效为柱的移去来模拟钢筋混凝土框架结构在失去边跨中柱时其上方的钢筋混凝土框架梁在跨度成倍时的情形,研究钢筋混凝土框架柱下支撑移去后框架梁的动力响应和剪切破坏机理,研究结果表明:梁KJL01、KJL02的破坏形态为弯曲破坏,梁KJL-2、KJL-3、KJL-4的破坏形态为剪切破坏。通过计算得到弯曲DCR值在1.7～1.9之间,剪切DCR值不大于1.2。当梁发生剪切破坏时,拱效应不能充分发挥,使得梁的极限承载力降低,所以在建筑结构抗倒塌设计时必须按照“强剪弱弯”的原则进行抗剪设计。
对无阻尼单自由度弹塑性系统动力响应进行分析,分析结果表明:弹塑性结构体系的弯曲DCR的取值与延性系数β有关,当β= 2时,DCR取值为0.75。对突加荷载作用下单自由度有阻尼系统在弹性阶段的动力响应进行分析,得到系统达到最大位移的时间与升载时间无关,只取决于结构的自振周期T,并且系统进入塑性阶段而不破坏的最短时间为T/4。
If the frame column is destroyed, progressive collapse may happen in the building, causing serious casualties and economic losses, so how to prevent the progressive collapse has become one of important issues for structure Engineering. Ductility is one of the main factors to prevent the vertical progressive collapse of the building, so the building should avoid shear failure prior to bending failure.
The load coming from the secondary beam and cast-in-place plate in 1/4 span, 1/2 span, 3/4 span by the imposition of weight on the reinforced concrete beams fixed at both ends has been simulated, and the case that reinforced concrete frame beams doubled has been simulated when reinforced concrete frame beam loses mid column in the side at the midspan by automatic detacher. It studies dynamic response and shear failure mechanism when reinforced concrete frame column damaged suddenly, and experimental results indicate that: damage patterns of beams KJL01, KJL02 are bending failure, and damage patterns of beams KJL-2, KJL-3, KJL-4 are shear failure. The values of bending DCR are between 1.7 and 1.9, and shear DCR are not more than 1.2. When the beam occurs shear failure, the arch effect can’t bring into full play, and consequently makes the ultimate capacity of beam lowering, so the building must configurate reinforced in the building design to resist progressive collapse in accordance with "strong shear weak bending".
Dynamic response of single degree of freedom without damping elastic-plastic system has been analysed, the results show that: the value of bending DCR of elastic-plastic system has something to do with the ductility factorβ, whenβ=2 and the value of DCR is 0.75. Dynamic response of single degree of freedom elastic damping system has been analysised to find that the time to the maximum displacement has nothing with loading time only depending on the natural cycle T of the building, the shortest time when the system goes into Plastic stage and without undermining is T/4.
引文
[1] ELLINGWOOD BRUCE R. Mitigating Risk from Abnormal Loads and Progressive Collapse. Journal of Performance of Constructed Facilities[J]. 2006,20(4): 315-323.
[2]胡联合.“当代世界反恐怖斗争的基本措施”当代世界恐怖主义与对策[C].东方出版社,2001:1-5.
[3]双子大厦坍塌给建筑防火带来的反思[EB/OL]. http://www.sc119.gov.cn/Get/Mavin/Architecture/0553017584292911.htm,2002-3-6.
[4]王雷鸣,翟伟.河北省石家庄“3·16”特大爆炸案侦破纪实[EB/OL]. http://www.people.com.cn/GB/shehui/47/20010324/424858.html,2001-3-24.
[5] BURNETT. The Avoidance of Progressive Collapse: Regulatory Approaches to the Problem, National Bureau of Standards[J]. Washington,D.C. E.F.P., 1975.
[6] YOKEL F.Y. Wright, R.N. Stone, U.S. Office Building in Moscow Journal of Performance of Constructed Facilities, American Society of Civil Engineers[J]. W.C. Progressive Collapse February, 1989,3(1).
[7] Progressive Collapse Analysis and Design Guidelines for New Federal Office Buildings and Major Modernization Project[M]. U.S. General Services Administration, 2000.
[8] STEVEN M. Baldrige, Francis K. Humay. Preventing Progressive Collapse in Concrete Buildings, Concrete international[J]. 2003.
[9] Guo Wenjun, RAMON GILSANZ P. E. Nonlinear Static Analysis Procedure-Progressive Collapse Evaluation, Design Engineers of Gilsanz Murray Steficek[J]. 2003.
[10] LUCCIONI B.M. and AMBROSINI R.D. and Danesi R.F. Analysis of building collapse under blast loads[J]. Engineering Structures, 2004,(24):63-71.
[11]潘岳,夏宪成.建筑物突然倒塌的模式与作用机制探讨[J].建筑安全,1999,14(5).
[12]王新建.建筑物防爆研究[J].公安大学学报,1999,2(14).
[13]秦东,范立础.钢筋混凝土结构倒塌全过程数值模拟[J].同济大学学报,2001,1(29).
[14]陆新征,江见鲸.世界贸易中心飞机撞击后倒塌过程的仿真分析[J].土木工程学报,2001,6.
[15] GHABOSSI J, WAMILLAVEC, J ISENBERG. R/C structures under impulsive loading[J]. Journal of Structural Engineering, 1984,110(3):505-522.
[16] KRAUTHAMMER T, ASSADI-LAMOUKIA, SHANNA H. M. Analysis of impulsively loaded reinforced concreete elementsⅠ[J]. Computers and Structures, 1993,48(5):851-860.
[17] TIMOSHENKO S. P. On the correction for shear of the differential equation for transverse vibraions of prismatic bars[J ]. Philosophical Magazine, 1921, 41: 744-746.
[18] ROSS T. J. Direct shear failure in reinforced concrete beams under impulsive loading[R]. Air Force Weapons Laboratory , Kirtland Air Force Base, 1983.
[19]方秦,柳锦春,张亚栋,等.爆炸荷载作用下钢筋混凝土梁破坏形态有限元分析[J].工程力学,2001,18(2):1-9.
[20]吴平安.化爆条件下钢筋混凝土梁的剪切破坏分析[J].解放军理工大学工程兵学院,1999.
[21]吴平安,方秦,王年桥,郭志昆.脉冲荷载作用下钢筋砼梁破坏形态分析[J].解放军理工大学学报,2000,1(6):1-7.
[22]柳锦春,方秦,龚自明,范俊余.爆炸荷载作用下钢筋混凝土梁的动力响应及破坏形态分析[J].爆炸与加载,2003,23(1):25-30.
[23]方秦,吴平安.爆炸荷载作用下影响RC梁破坏形态的主要因素分析[J].计算力学学报,2003,20(1):39-42.
[24]陈肇元,施岚青.钢筋混凝土梁在静速和快速变形下的弯曲性能[J].科学研究报告集,第4集,钢筋混凝土结构构件在加载荷载下的性能,1986:8-12.
[25]陈肇元,罗家谦.钢筋混凝土梁在爆炸压力荷载下的动力响应[J].科学研究报告集,第4集,钢筋混凝土结构构件在加载荷载下的性能,1986:13-16.
[26] SLAW SON T. R. Dynamic Shear failure of shallow-buried flat-rooted reinforced concrete structures subjected to blast loading[R]. Report No. SL-80-7, Mississipi,U.S.A. Waterways Experiment Station of U.S.A., 1984.
[27] HAWKINS N. M. Dynamic shear resistance of reinforced concrete[R]. Letter report to U.S.Navy, 1981.
[28] Fang Qin. Response characteristics of buried structures subjected to impulsive loadings[C]. Proc. of Sixth International Symposium on the Interaction of Nonnuclear Munition swith Structures. U.S.A., 1993: 277-281.
[29]阚永魁.混凝土在快速变形下的抗拉强度[J].科学研究报告集,第4集,钢筋混凝土结构构件在加载荷载下的性能,1986:84-88.
[30]苏幼坡等.钢筋混凝土建筑抗连续倒塌设计综述[J].城市与工程安全减灾研究与进展,2006:258-263.
[31] Design of Buildings to Resist Progressive Collapse[M]. UFC 4-023-03, U.S. Department of Defense, 25 January, 2005.
[32] Building code requirements for structural concrete and commentary (ACI 318RM-02)[S]. American Concrete Institute, 2002.
[33]混凝土结构设计规范[S],GB50010-2002.中国建筑工业出版社,2002.
[34]建筑抗震设计规范[S],GB50011-2001.中国建筑工业出版社,2002.
[35]建筑结构荷载规范[S],GB5009-2001.中国建筑工业出版社,2002.
[36]过镇海,时旭东编著.钢筋混凝土原理和分析[M].北京:清华大学出版社,2005.
[37]杨桂通,熊祝华编著.塑性动力学[M].北京:清华大学出版社,1984.
[38]盛宏玉编著.结构动力学[M].安徽:合肥工业大学出版社,2005.
[39]孙祥,徐流美,吴清编著. MATLAB7.0基础教程[M].北京:清华大学出版社,2005.
[40] DELORES M. ETTER, DAVID C. KUNCICKY, HOLLY MOORE著,邱李华译. MATLAB7及工程问题解决方案[M].北京:机械工业出版社,2006.3.
[41]商霖,宁建国,孙远翔.强加载载荷作用下钢筋混凝土本构关系的研究[J].固体力学学报,2005,26(2).
[42]胡时胜,王道荣.加载载荷下混凝土材料的动态本构关系[J].爆炸与加载,2002,22(3):242-247.
[43]商霖,宁建国.强加载载荷作用下混凝土本构关系[J].工程力学,2005,22(2):116-120.
[2]胡联合.“当代世界反恐怖斗争的基本措施”当代世界恐怖主义与对策[C].东方出版社,2001:1-5.
[3]双子大厦坍塌给建筑防火带来的反思[EB/OL]. http://www.sc119.gov.cn/Get/Mavin/Architecture/0553017584292911.htm,2002-3-6.
[4]王雷鸣,翟伟.河北省石家庄“3·16”特大爆炸案侦破纪实[EB/OL]. http://www.people.com.cn/GB/shehui/47/20010324/424858.html,2001-3-24.
[5] BURNETT. The Avoidance of Progressive Collapse: Regulatory Approaches to the Problem, National Bureau of Standards[J]. Washington,D.C. E.F.P., 1975.
[6] YOKEL F.Y. Wright, R.N. Stone, U.S. Office Building in Moscow Journal of Performance of Constructed Facilities, American Society of Civil Engineers[J]. W.C. Progressive Collapse February, 1989,3(1).
[7] Progressive Collapse Analysis and Design Guidelines for New Federal Office Buildings and Major Modernization Project[M]. U.S. General Services Administration, 2000.
[8] STEVEN M. Baldrige, Francis K. Humay. Preventing Progressive Collapse in Concrete Buildings, Concrete international[J]. 2003.
[9] Guo Wenjun, RAMON GILSANZ P. E. Nonlinear Static Analysis Procedure-Progressive Collapse Evaluation, Design Engineers of Gilsanz Murray Steficek[J]. 2003.
[10] LUCCIONI B.M. and AMBROSINI R.D. and Danesi R.F. Analysis of building collapse under blast loads[J]. Engineering Structures, 2004,(24):63-71.
[11]潘岳,夏宪成.建筑物突然倒塌的模式与作用机制探讨[J].建筑安全,1999,14(5).
[12]王新建.建筑物防爆研究[J].公安大学学报,1999,2(14).
[13]秦东,范立础.钢筋混凝土结构倒塌全过程数值模拟[J].同济大学学报,2001,1(29).
[14]陆新征,江见鲸.世界贸易中心飞机撞击后倒塌过程的仿真分析[J].土木工程学报,2001,6.
[15] GHABOSSI J, WAMILLAVEC, J ISENBERG. R/C structures under impulsive loading[J]. Journal of Structural Engineering, 1984,110(3):505-522.
[16] KRAUTHAMMER T, ASSADI-LAMOUKIA, SHANNA H. M. Analysis of impulsively loaded reinforced concreete elementsⅠ[J]. Computers and Structures, 1993,48(5):851-860.
[17] TIMOSHENKO S. P. On the correction for shear of the differential equation for transverse vibraions of prismatic bars[J ]. Philosophical Magazine, 1921, 41: 744-746.
[18] ROSS T. J. Direct shear failure in reinforced concrete beams under impulsive loading[R]. Air Force Weapons Laboratory , Kirtland Air Force Base, 1983.
[19]方秦,柳锦春,张亚栋,等.爆炸荷载作用下钢筋混凝土梁破坏形态有限元分析[J].工程力学,2001,18(2):1-9.
[20]吴平安.化爆条件下钢筋混凝土梁的剪切破坏分析[J].解放军理工大学工程兵学院,1999.
[21]吴平安,方秦,王年桥,郭志昆.脉冲荷载作用下钢筋砼梁破坏形态分析[J].解放军理工大学学报,2000,1(6):1-7.
[22]柳锦春,方秦,龚自明,范俊余.爆炸荷载作用下钢筋混凝土梁的动力响应及破坏形态分析[J].爆炸与加载,2003,23(1):25-30.
[23]方秦,吴平安.爆炸荷载作用下影响RC梁破坏形态的主要因素分析[J].计算力学学报,2003,20(1):39-42.
[24]陈肇元,施岚青.钢筋混凝土梁在静速和快速变形下的弯曲性能[J].科学研究报告集,第4集,钢筋混凝土结构构件在加载荷载下的性能,1986:8-12.
[25]陈肇元,罗家谦.钢筋混凝土梁在爆炸压力荷载下的动力响应[J].科学研究报告集,第4集,钢筋混凝土结构构件在加载荷载下的性能,1986:13-16.
[26] SLAW SON T. R. Dynamic Shear failure of shallow-buried flat-rooted reinforced concrete structures subjected to blast loading[R]. Report No. SL-80-7, Mississipi,U.S.A. Waterways Experiment Station of U.S.A., 1984.
[27] HAWKINS N. M. Dynamic shear resistance of reinforced concrete[R]. Letter report to U.S.Navy, 1981.
[28] Fang Qin. Response characteristics of buried structures subjected to impulsive loadings[C]. Proc. of Sixth International Symposium on the Interaction of Nonnuclear Munition swith Structures. U.S.A., 1993: 277-281.
[29]阚永魁.混凝土在快速变形下的抗拉强度[J].科学研究报告集,第4集,钢筋混凝土结构构件在加载荷载下的性能,1986:84-88.
[30]苏幼坡等.钢筋混凝土建筑抗连续倒塌设计综述[J].城市与工程安全减灾研究与进展,2006:258-263.
[31] Design of Buildings to Resist Progressive Collapse[M]. UFC 4-023-03, U.S. Department of Defense, 25 January, 2005.
[32] Building code requirements for structural concrete and commentary (ACI 318RM-02)[S]. American Concrete Institute, 2002.
[33]混凝土结构设计规范[S],GB50010-2002.中国建筑工业出版社,2002.
[34]建筑抗震设计规范[S],GB50011-2001.中国建筑工业出版社,2002.
[35]建筑结构荷载规范[S],GB5009-2001.中国建筑工业出版社,2002.
[36]过镇海,时旭东编著.钢筋混凝土原理和分析[M].北京:清华大学出版社,2005.
[37]杨桂通,熊祝华编著.塑性动力学[M].北京:清华大学出版社,1984.
[38]盛宏玉编著.结构动力学[M].安徽:合肥工业大学出版社,2005.
[39]孙祥,徐流美,吴清编著. MATLAB7.0基础教程[M].北京:清华大学出版社,2005.
[40] DELORES M. ETTER, DAVID C. KUNCICKY, HOLLY MOORE著,邱李华译. MATLAB7及工程问题解决方案[M].北京:机械工业出版社,2006.3.
[41]商霖,宁建国,孙远翔.强加载载荷作用下钢筋混凝土本构关系的研究[J].固体力学学报,2005,26(2).
[42]胡时胜,王道荣.加载载荷下混凝土材料的动态本构关系[J].爆炸与加载,2002,22(3):242-247.
[43]商霖,宁建国.强加载载荷作用下混凝土本构关系[J].工程力学,2005,22(2):116-120.