摘要
连续倒塌是结构系统的非线性动力行为,准确评估动力效应是建立简化工程设计方法的核心工作。为了研究钢筋混凝土梁柱子结构动力连续倒塌机理和动力效应,对4个尺寸和材料完全相同的试件分别开展了1次静力和4次动力试验。试验结果表明:动力连续倒塌的应力集中和非对称受力现象更加明显,且受材料应变率效应的影响,梁端受拉裂缝集中开展,受压区混凝土压碎剥落区域较小;考虑到动力损伤和材料应变率对结构自身抗力特征的影响,广义动力抗力能够更加准确地描述实际动力连续倒塌过程中的抗力需求;动力损伤和材料应变率效应使得结构的动力放大效应增强,实际动力放大系数均大于传统理论预测值。
Progressive collapse is a nonlinear dynamic behavior of structure systems. The key issue in establishing the simplified method for the practical engineering design is to evaluate the dynamic effect accurately. To investigate the dynamic progressive collapse mechanism and the dynamic effect of reinforced concrete substructures, one static and four dynamic experiments were conducted on four specimens, which had the identical dimensions and material properties. The results indicated that the stress concentration and asymmetric deformation in the dynamic tests were severer than those in the static test due to the high strain rate effect. Thus, the cracks developed intensively at the beam ends and the concrete spalling area caused by compression was relatively small in dynamic tests. The general dynamic resistance, in which the effects of dynamic damage and high strain rate to the structural resistance were inherently considered, was able to accurately predict the resistance demand in the real progressive collapse process. In addition, the dynamic amplification effect was enhanced by the effect of dynamic damage and high strain rate, thus the practical dynamic amplification factors were larger than the predicted values of the conventional theory.
引文
[1]ASCE/SEI 7-10,Minimum design loads for buildings and other structures[S].Reston,Virginia:American Society of Civil Engineers,2010.
[2]郭义庆,喻军.单柱失效下结构连续倒塌的动力响应分析[J].工程力学,2017,34(4):72―77.Guo Yiqing,Yu Jun.Dynamic structural response of progressive collapse under a single-column-removal scenario[J].Engineering Mechanics,2017,34(4):72―77.(in Chinese)
[3]喻莹,谭长波,金林,等.基于有限质点法的单层球面网壳强震作用下连续倒塌破坏研究[J].工程力学,2016,33(5):134―141.Yu Ying,Tan Changbo,Jin Lin,et al.Research on seismic progressive collapse of single-layer reticulated dome using the finite particle method[J].Engineering Mechanics,2016,33(5):134―141.(in Chinese)
[4]孟宝,钟炜辉,郝际平.不同跨度比下栓焊刚性连接梁柱子结构抗倒塌性能试验研究[J].工程力学,2018,35(1):79―87.Meng bao,Zhong Weihui,Hao Jiping.Experimental study on anti-collapse performance for beam-column assemblies with bolt and weld rigid connection based on different span ratio[J].Engineering Mechanics,2018,35(1):79―87.(in Chinese)
[5]潘毅,陈侠辉,姚蕴艺,等.基于抽柱法的无粘结预应力装配式框架结构连续倒塌分析[J].工程力学,2017,34(12):162―170.Pan Yi,Chen Xiahui,Yao Yunyi,et al.Progressive collapse analysis of unbonded post-tensioned precast RCframe structures using column removal method[J].Engineering Mechanics,2017,34(12):162―170.(in Chinese)
[6]Peng Z,Orton L S,Liu J,et al.Experimental study of dynamic progressive collapse in flat-plate buildings subjected to an interior column removal[J].Journal of Structural Engineering,ASCE,2018,144(8):04018094.
[7]Gao S,Xu M,Zhang S.Dynamic analysis of concrete-filled steel tube composite frame against progressive collapse based on benchmark model[J].Advances in Structural Engineering,2018,21(7):1021―1035.
[8]Ma K,Xu Y,Li W.Dynamic response analysis of steel frame with a sudden removal first floor column[J].Journal of Intelligent and Fuzzy Systems,2018,34(2):1133―1140.
[9]高佳明,刘伯权,黄华,等.带板钢筋混凝土框架连续倒塌理论分析[J].工程力学,2018,35(7):117―126.Gao Jiaming,Liu Boquan,Huang Hua,et al.Theoretical analysis on the progressive collapse of RC frame structures with slabs[J].Engineering Mechanics,2018,35(7):117―126.(in Chinese)
[10]周云,陈太平,胡翔,等.考虑周边结构约束影响的RC框架结构防连续倒塌性能研究[J].工程力学,2018,36(1):216―226.Zhou Yun,Chen Taiping,Hu Xiang,et al.Progressive collapse resistance of RC frame structures considering surrounding structural constraints[J].Engineering Mechanics,2018,36(1):216―226.(in Chinese)
[11]DOD2013,Design of buildings to resist progressive collapse[S].Washington D.C.:Department of Defense,2013.
[12]GSA2013,Alternate path analysis and design guidelines for progressive collapse resistance[S].Washington D.C.:the U.S.General Services Administration,2013.
[13]Marchand K,Mc Kay A,Stevens D.Development and application of linear and non-linear static approaches in UFC 4-023-03[C]//Lawrence G,Todd H,Mark W,Marc H.Proceedings of the 2009 Structures Congress.Texus:American Society of Civil Engineers,2009:1729―1738.
[14]李易,叶列平,陆新征.基于能量方法的RC框架结构连续倒塌抗力需求分析I:梁机制[J].建筑结构学报,2011,32(11):1―8.Li Yi,Ye Lieping,Lu Xinzheng.Progressive collapse resistance demand of RC frame structures based on energy method I:Beam mechanism[J].Journal of Building Structures,2011,32(11):1―8.(in Chinese)
[15]李易,陆新征,叶列平.框架结构连续倒塌抗力需求分析II:悬链线机制[J].建筑结构学报,2011,32(11):9―16.Li Yi,Lu Xinzheng,Ye Lieping.Progressive collapse resistance demand of RC frame structures based on energy method II:Catenary mechanism[J].Journal of Building Structures,2011,32(11):9―16.(in Chinese)
[16]Tian Y,Su Y.Dynamic response of reinforced concrete beams following instantaneous removal of a bearing column[J].International Journal of Concrete Structures and Materials,2011,5(1):19―28.
[17]Qian K,Li B.Performance of three-dimensional reinforced concrete beam-column substructures under loss of a corner column scenario[J].Journal of Structural Engineering,ASCE,2013,139(4):584―594.
[18]Qian K,Li B.Dynamic performance of RCbeam-column substructures under the scenario of the loss of a corner column-Experimental results[J].Engineering Structures,2012,42:154―167.
[19]Pham A T,Tan K H.Experimental study on dynamic responses of reinforced concrete frames under sudden column removal applying concentrated loading[J].Engineering Structures,2017,139:31―45.
[20]初明进,周育泷,陆新征,等.钢筋混凝土单向梁板子结构抗连续倒塌试验研究[J].土木工程学报,2016,49(2):31―40.Chu Mingjin,Zhou Yulong,Lu Xinzheng,et al.An experimental study on one-way reinforced concrete beam-slab substructures for resisting progressive collapse[J].China Civil Engineering Journal,2016,49(2):31―40.(in Chinese)
[21]Bischoff P H,Perry S H.Compressive behavior of concrete at high-strain rates[J].Materials and Structures,1991,24(144):425―450.
[22]Majzoobi G H,Mahmoudi A H,Moradi S.Ductile to brittle failure transition of HSLA-100 Steel at high strain rates and subzero temperatures[J].Engineering Fracture Mechanics,2016,158:179―193.
[23]Peng Z,Orton L S,Liu J,et al.Experimental study of dynamic progressive collapse in flat-plate buildings subjected to exterior column removal[J].Journal of Structural Engineering,ASCE,2017,143(9):04017125.