RC框架结构抗连续倒塌研究

Study on RC frames to resist progressive collapse

为研究钢筋混凝土结构在中柱失效工况下的抗连续倒塌性能,对移除中柱后的钢筋混凝土双跨梁结构进行pushdown加载,并对试件的破坏模式及承载能力进行观测。试验结果表明:中柱失效的钢筋混凝土双跨梁结构的压拱效应和悬链线效应可以抵抗连续倒塌的发生。采用有限元软件DIANA建模对试验结果进行了数值模拟分析,证明了数值模型的合理性。基于可靠的有限元模拟进行拓展参数分析,结果表明混凝土强度增加及跨高比减小有利于提高压拱效应的影响,配筋率的增大则降低压拱效应的影响。采用现有经典公式对第一峰值荷载进行分析,理论分析结果表明:Park模型的计算结果与有限元模拟结果较为接近,进一步证明了有限元模拟的可靠性。

In order to study the anti-progressive collapse behavior of reinforced concrete structures under the scenario of missing one middle column,pushdown tests are carried out to evaluate the failure mode,load bearing capacity,and deformation capacity of two-span RC beams after the removal of a middle column. The experimental results indicate that the compressive arch effect and catenary effect could be developed to prevent progressive collapse. A numerical model is built up by commercial finite element software DIANA. It is found that the model could simulate the global behavior of the specimens well. An extended parameter analysis is carried out based on the validated finite element simulation. The results show that the increase of concrete strength and the decrease of span depth ratio are beneficial to the effect of compression arch,and the increase of reinforcement ratio reduces the effect of compression arch. The existing classical formula is used to analyze the firstpeak load. The theoretical analysis results show that the results of Park model are close to those of the finite element simulation,and the reliability of the finite element simulation is proved.