建筑结构学报2024，Vol.45Issue(7)：153-165,13.DOI:10.14006/j.jzjgxb.2022.0942
高温下及高温冷却后中柱失效足尺RC梁-柱子结构抗连续倒塌性能
Progressive collapse-resistant performance of during and after elevated-temperature full-scale RC beam-column assemblies under a middle column removal scenario
摘要
Abstract
To study the failure mechanism and collapse-resistant mechanism of fire-exposed reinforced concrete(RC)frame structures,full-scaled three-dimensional finite element models were developed based on thermal-mechanical techniques in this study.After verifying the accuracy of the FE models,the collapse-resistant performance of full-scale RC beam-column assemblies under a middle column removal scenario during/after elevated temperature were analyzed.Based on the FE analyses,the effects of fire duration,the side column subjected to fire and seismic detailing were discussed.Furthermore,the previous research based on 1/2 scale assemblies was used to conduct comparative study.The FE results indicate that the first peak load of the assemblies significantly decreases during elevated temperature due to the degradation of properties of rebar and concrete.At a fire duration of 30 min,the failure mode of fire-exposed assemblies is similar to that of assemblies in ambient temperature,the failure of assemblies is dominated by the fracture of beam rebar at the beam ends connected to the middle column.When the fire duration exceeds 60 min,the failure of assemblies is controlled by the fracture of beam top rebar at the location of rebar curtailment.The assemblies after high temperature can develop compressive arch action and catenary action in sequence to resist collapse,and the ultimate deformation capacity and load resistance capacity are similar to those of assemblies in ambient temperature.In addition,when the side columns are exposed to fire for more than 60 min and then cooled down,they suffer compression failure under the pseudo static load.For a fire duration of 30-120 min,adopting seismic detailing can increase the ultimate load and deformation capacities of the assemblies after elevated temperature by 51％and 39％at least,respectively.关键词
钢筋混凝土结构/梁-柱子结构/有限元分析/高温/连续倒塌/抗力机制Key words
reinforced concrete structure/beam-column assembly/finite element analysis/elevated temperature/progressive collapse/load-resistant mechanism分类
建筑与水利引用本文复制引用
金浏,兰冬璆,张仁波,钱凯,李健,杜修力..高温下及高温冷却后中柱失效足尺RC梁-柱子结构抗连续倒塌性能[J].建筑结构学报,2024,45(7):153-165,13.基金项目
国家自然科学基金项目(51978022),北京市自然科学基金项目(JQ22025). （51978022）
