钢筋混凝土梁-板子结构抗连续性倒塌性能研究

该文通过试验与有限元模拟研究边柱失效工况下钢筋混凝土（RC）梁-板子结构抗连续倒塌性能。在实验室通过对RC梁-板子结构缩尺模型开展pushdown试验研究梁-板子结构的破坏模态，并进一步讨论了梁-板子结构在倒塌过程中的荷载传递机理和抗力机制。试验结果表明:RC梁-板子结构在倒数第二个边柱失效下可以形成有效的梁机制、压拱机制、悬链线机制以及拉膜机制抵抗倒塌。在小变形阶段，楼板在负弯矩区作为梁翼缘可以显著提升RC梁抗弯承载力（T型梁作用）；在大变形阶段，楼板发展拉膜作用早于梁发展悬链线机制。此外，根据有限元软件LSDYNA开展的数值分析结果表明:楼板提升RC框架屈服承载力与极限承载力分别高达65%和61%。

BEHAVIOR OF RC BEAM-SLAB SUBSTRUCTURES TO RESIST PROGRESSIVE COLLAPSE

The progressive collapse resistance of RC beam-slab substructure under the loss of a penultimate side column is studied through the experimental and numerical analysis. A scaled RC beam-slab substructure is carried out in the laboratory by considering the effect of service loading during collapse. The failure modes, load redistribution mechanism, and load resisting mechanism are investigated and discussed. The experimental results showed that the beam action, compression arch action, catenary action, and tensile membrane action can be mobilized to resist the collapse of RC beam-slab structures under a penultimate column failure scenario. In the initial deformation stage, the flange effects of the slab could enhance the flexural resistance of RC beams. However, the mobilization of tensile membrane action in RC slabs is earlier than that of catenary action in RC beams. In addition, the numerical analysis based on the commercial finite element software LSDYNA showed that the floor slabs increase the yield strength and ultimate bearing capacity of a RC frame up by 65% and 61%, respectively.