楼板对RC空间框架结构抗连续倒塌性能影响试验研究
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摘要
为研究楼板对RC空间框架结构抗连续倒塌性能的影响作用,文章以汶川地震中完全倒塌的漩口中学教学楼为原型结构,设计3个单层2×2跨1/3缩尺模型,包括2个带楼板子结构和1个纯框架子结构,通过拟静力加载试验研究RC框架结构在拆除中柱状态下的连续倒塌破坏过程。试验结果表明:纯框架子结构首先进入梁机制阶段,框架梁内产生轴向压力,产生"压拱效应",在梁端部截面抗弯承载力丧失后,进入悬链线机制阶段,依靠梁内部钢筋拉结力抵抗上部荷载。对比分析带楼板子结构与纯框架子结构试验结果,由于楼板的"薄膜效应"使梁机制峰值承载力提高了145%,悬链线机制峰值承载力提高了75%,楼板显著提高了梁机制和悬链线机制的抗连续倒塌能力。增加板厚增加梁板的"压拱效应",极大提高梁机制承载力,然而大变形下梁板开始不协同作用,板发生冲切破坏,降低了悬链线阶段承载力和延性。
To study the effect of floor slab on the progressive collapse of reinforced concrete(RC) spatial frame,three one-story two-by-two bays 1/3 scaled models with the Xuankou middle school building collapsed in Wenchuan earthquake taken as the prototype structure were constructed. Among them, two models incorporate floor slab sub-structures and one is a pure framed sub-structure. The progressive collapse procedure of RC frame after removing the middle columns under the quasi-static loading can be experimentally studied. The experimental results show that the pure framed sub-structure may first exhibit the beam mechanism, with the occurrence of the "compressive arch" due to the axial compressive forces in the frame beams. Once the flexural capacity in the beam ends is lost, and the pure framed sub-structure goes into the stage of catenary mechanism with the tensile force of steel in beams to resist the loads from upper structure. Based on the comparison of experimental results between floor slab sub-structure and pure framed sub-structure, it is found that the peak capacities of beam mechanism and catenary mechanism are increased by 145% and 75%, respectively, due to the"membrane effect", indicating that the slabs can significantly enhance the progressive collapse capacity of beam mechanism and catenary mechanism. Increasing the slab thickness increases the "compressive arch'' of beams and slabs, and hence significantly enhances the capacity of beam mechanism. However, beams and slabs fail to work together under large deformation, leading to the punch failure of slabs and the decrease of the capacity and ductility of catenary mechanism.
To study the effect of floor slab on the progressive collapse of reinforced concrete(RC) spatial frame,three one-story two-by-two bays 1/3 scaled models with the Xuankou middle school building collapsed in Wenchuan earthquake taken as the prototype structure were constructed. Among them, two models incorporate floor slab sub-structures and one is a pure framed sub-structure. The progressive collapse procedure of RC frame after removing the middle columns under the quasi-static loading can be experimentally studied. The experimental results show that the pure framed sub-structure may first exhibit the beam mechanism, with the occurrence of the "compressive arch" due to the axial compressive forces in the frame beams. Once the flexural capacity in the beam ends is lost, and the pure framed sub-structure goes into the stage of catenary mechanism with the tensile force of steel in beams to resist the loads from upper structure. Based on the comparison of experimental results between floor slab sub-structure and pure framed sub-structure, it is found that the peak capacities of beam mechanism and catenary mechanism are increased by 145% and 75%, respectively, due to the"membrane effect", indicating that the slabs can significantly enhance the progressive collapse capacity of beam mechanism and catenary mechanism. Increasing the slab thickness increases the "compressive arch'' of beams and slabs, and hence significantly enhances the capacity of beam mechanism. However, beams and slabs fail to work together under large deformation, leading to the punch failure of slabs and the decrease of the capacity and ductility of catenary mechanism.
引文
[1]苏幼坡,王兴国,宋晓胜,等.钢筋混凝土框架梁拱效应的试验研究[J].西安建筑科技大学学报:自然科学版,2009,41(4):477-484(Su Youpo,Wang Xingguo,Song Xiaosheng,et al.Experimental investigation on the arching action in reinforced concrete frame-beams[J].Journal of Xi'an University of Architecture&Technology,2009,41(4):477-484(in Chinese))
[2]何庆锋,易伟建.考虑悬索作用钢筋混凝土梁柱子结构抗倒塌性能试验研究[J].土木工程学报,2011,44(4):52-59(He Qingfeng,Yi Weijian.Experimental study of the collapse-resistant behavior of RCbeam-column sub-structures considering catenary action[J].China Civil Engineering Journal,2011,44(4):52-59(in Chinese))
[3]Sasani M,Werner A,Kazemi A.Bar fracture modeling in progressive collapse analysis of reinforced concrete structures[J].Engineering Structures,2011,33(2):401-409
[4]Orton S L.Development of a CFRP system to provide continuity in existing reinforced concrete buildings vulnerable to progressive collapse[D].Austin:University of Texas at Austin,2007
[5]Choi H,Kim J.Progressive collapse-resisting capacity of RC beam-column sub-assemblage[J].Magazine of Concrete Research,2011,63(4):297-310
[6]易伟建,何庆锋,肖岩.钢筋混凝土框架结构抗倒塌性能的试验研究[J].建筑结构学报,2007,28(5):104-109(Yi Weijian,He Qingfeng,Xiao Yan.Collapse performance of RC frame structure[J].Journal of Building Structures,2007,28(5):104-109,117(in Chinese))
[7]Yu J,Tan K H.Experimental and numerical investigation on progressive collapse resistance of reinforced concrete beam column sub-assemblages[J].Engineering Structures,2013,55:90-106
[8]王浩,李易,陆新征,等.单层钢筋混凝土框架结构水平向连续倒塌试验研究[J].建筑结构学报,2016,37(10):65-72(Wang Hao,Li Yi,Lu Xinzheng,et al.Experimental investigation on horizontal progressive collapse of one-story reinforced concrete frame[J].Journal of Building Structures,2016,37(10):65-72(in Chinese))
[9]单思镝.RC填充墙框架连续倒塌机制研究[D].哈尔滨:哈尔滨工业大学,2016(Shan Sidi.Research on progressive collapse mechanisms of RC frames with infill walls[D].Harbin:Harbin Institute of Technology,2016(in Chinese))
[10]戎贤,仉庆文,赵玉婷.RC异形柱框架抗连续倒塌试验研究[J].建筑科学,2015,31(11):74-78(Rong Xian,Zhang Qingwen,Zhao Yuting.Experimental research on RC special-shaped columns frame's progressive collapse resistance[J].Building Science,2015,31(11):74-78(in Chinese))
[11]易伟建,张凡榛.钢筋混凝土板柱结构抗倒塌性能试验研究[J].建筑结构学报,2012,33(6):35-41(Yi Weijian,Zhang Fanzhen.Experimental study on collapse performance of a RC flat plate frame structure[J].Journal of Building Structures,2012,33(6):35-41(in Chinese))
[12]杨涛,蓝文武,钱凯.不同板中配筋形式下板柱结构的连续倒塌性能[J].华南理工大学学报:自然科学版,2014,42(10):110-116(Yang Tao,Lan Wenwu,Qian Kai.Progressive collapse performance of flat slab structures with different slab reinforcement details[J].Journal of South China University of Technology:Natural Science Edition,2014,42(10):110-116(in Chinese))
[13]任沛琪.钢筋混凝土梁板子结构在边柱失效下的连续倒塌试验研究[D].北京:清华大学,2015(Ren Peiqi.Experimental study on the progressive collapse resistance of reinforced concrete beam-slab substructures under a middle-column-removal scenario[D].Beijing:Tsinghua University,2015(in Chinese))
[14]Ren P,Li Y,Lu X,et al.Experimental investigation of progressive collapse resistance of one-way reinforced concrete beam-slab substructures under a middlecolumn-removal scenario[J].Engineering Structures,2016,118:28-40
[15]Qian K,Li B.Slab effects on response of reinforced concrete substructures after loss of corner column[J].ACI Structural Journal,2012,109(6):845-869
[16]Qian K,Li B,Ma J X.Load-carrying mechanism to resist progressive collapse of RC buildings[J].Journal of Structural Engineering,2014,141(2):4014107-4014101
[17]黄思凝,郭迅,孙得璋,等.外廊式RC框架破坏机理的振动台试验研究[J].工程力学,2016,33(12):63-71,85(Huang Sining,Guo Xun,Sun Dezhang,et al.Shaking table test on failure mechanism of RC frame with exterior corridor[J].Engineering Mechanics,2016,33(12):63-71,85(in Chinese))
[18]杨伟松,郭迅,许卫晓,等.翼墙-框架结构振动台试验研究及有限元分析[J].建筑结构学报,2015,36(2):96-103(Yang Weisong,Guo Xun,Xu Weixiao,et al.Shaking table test and finite element analysis of wing wall-frame structure[J].Journal of Building Structures,2015,36(2):96-103(in Chinese))
[2]何庆锋,易伟建.考虑悬索作用钢筋混凝土梁柱子结构抗倒塌性能试验研究[J].土木工程学报,2011,44(4):52-59(He Qingfeng,Yi Weijian.Experimental study of the collapse-resistant behavior of RCbeam-column sub-structures considering catenary action[J].China Civil Engineering Journal,2011,44(4):52-59(in Chinese))
[3]Sasani M,Werner A,Kazemi A.Bar fracture modeling in progressive collapse analysis of reinforced concrete structures[J].Engineering Structures,2011,33(2):401-409
[4]Orton S L.Development of a CFRP system to provide continuity in existing reinforced concrete buildings vulnerable to progressive collapse[D].Austin:University of Texas at Austin,2007
[5]Choi H,Kim J.Progressive collapse-resisting capacity of RC beam-column sub-assemblage[J].Magazine of Concrete Research,2011,63(4):297-310
[6]易伟建,何庆锋,肖岩.钢筋混凝土框架结构抗倒塌性能的试验研究[J].建筑结构学报,2007,28(5):104-109(Yi Weijian,He Qingfeng,Xiao Yan.Collapse performance of RC frame structure[J].Journal of Building Structures,2007,28(5):104-109,117(in Chinese))
[7]Yu J,Tan K H.Experimental and numerical investigation on progressive collapse resistance of reinforced concrete beam column sub-assemblages[J].Engineering Structures,2013,55:90-106
[8]王浩,李易,陆新征,等.单层钢筋混凝土框架结构水平向连续倒塌试验研究[J].建筑结构学报,2016,37(10):65-72(Wang Hao,Li Yi,Lu Xinzheng,et al.Experimental investigation on horizontal progressive collapse of one-story reinforced concrete frame[J].Journal of Building Structures,2016,37(10):65-72(in Chinese))
[9]单思镝.RC填充墙框架连续倒塌机制研究[D].哈尔滨:哈尔滨工业大学,2016(Shan Sidi.Research on progressive collapse mechanisms of RC frames with infill walls[D].Harbin:Harbin Institute of Technology,2016(in Chinese))
[10]戎贤,仉庆文,赵玉婷.RC异形柱框架抗连续倒塌试验研究[J].建筑科学,2015,31(11):74-78(Rong Xian,Zhang Qingwen,Zhao Yuting.Experimental research on RC special-shaped columns frame's progressive collapse resistance[J].Building Science,2015,31(11):74-78(in Chinese))
[11]易伟建,张凡榛.钢筋混凝土板柱结构抗倒塌性能试验研究[J].建筑结构学报,2012,33(6):35-41(Yi Weijian,Zhang Fanzhen.Experimental study on collapse performance of a RC flat plate frame structure[J].Journal of Building Structures,2012,33(6):35-41(in Chinese))
[12]杨涛,蓝文武,钱凯.不同板中配筋形式下板柱结构的连续倒塌性能[J].华南理工大学学报:自然科学版,2014,42(10):110-116(Yang Tao,Lan Wenwu,Qian Kai.Progressive collapse performance of flat slab structures with different slab reinforcement details[J].Journal of South China University of Technology:Natural Science Edition,2014,42(10):110-116(in Chinese))
[13]任沛琪.钢筋混凝土梁板子结构在边柱失效下的连续倒塌试验研究[D].北京:清华大学,2015(Ren Peiqi.Experimental study on the progressive collapse resistance of reinforced concrete beam-slab substructures under a middle-column-removal scenario[D].Beijing:Tsinghua University,2015(in Chinese))
[14]Ren P,Li Y,Lu X,et al.Experimental investigation of progressive collapse resistance of one-way reinforced concrete beam-slab substructures under a middlecolumn-removal scenario[J].Engineering Structures,2016,118:28-40
[15]Qian K,Li B.Slab effects on response of reinforced concrete substructures after loss of corner column[J].ACI Structural Journal,2012,109(6):845-869
[16]Qian K,Li B,Ma J X.Load-carrying mechanism to resist progressive collapse of RC buildings[J].Journal of Structural Engineering,2014,141(2):4014107-4014101
[17]黄思凝,郭迅,孙得璋,等.外廊式RC框架破坏机理的振动台试验研究[J].工程力学,2016,33(12):63-71,85(Huang Sining,Guo Xun,Sun Dezhang,et al.Shaking table test on failure mechanism of RC frame with exterior corridor[J].Engineering Mechanics,2016,33(12):63-71,85(in Chinese))
[18]杨伟松,郭迅,许卫晓,等.翼墙-框架结构振动台试验研究及有限元分析[J].建筑结构学报,2015,36(2):96-103(Yang Weisong,Guo Xun,Xu Weixiao,et al.Shaking table test and finite element analysis of wing wall-frame structure[J].Journal of Building Structures,2015,36(2):96-103(in Chinese))