To prevent disproportionate collapse under an extreme loading event, a sudden column loss scenario is often used to ensure the structure has suitable robustness. This study aims to investigate experimentally the dynamic response of reinforced concrete flat slabs after a sudden column loss. Seven 1/3 scale reinforced concrete flat slabs were tested under static load increases or dynamic column removal cases with different supports removed. Reaction forces and deflections were recorded throughout, along with reinforcement strains and concrete cracking patterns. During dynamic tests, a high speed camera was used to capture the dynamic motion.ududThe experiments demonstrated that flat slabs, in general, are able to redistribute their loading effectively after a column loss. Although large levels of damage were observed, collapse due to flexural failure did not occur. However, punching shear was shown to be an issue due to the additional vertical loading on the adjacent supports. The inclusion of continuous bottom reinforcement through a column did not significantly improve the capacity, as the new load path is not primarily through the removed column location. The results also indicate that the dynamic effects due to a sudden column loss can be significant as deflections of up to 1.5 times the static case were measured within the elastic range. It is also shown that the Dynamic Amplification Factor (DAF) reduces when nonlinear damaging effects are included, which implies conventional code-based design methods for flat slab structures may be over conservative. Additionally, the increase in material strength due the strain rates is not viewed to be significant.
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机译：为了防止在极端载荷事件下不成比例的坍塌，经常使用突然的立柱损失情况以确保结构具有适当的坚固性。这项研究旨在通过实验研究钢筋混凝土平板在突然的立柱损失后的动力响应。在静载荷增加或动柱拆除情况下，去除了不同的支撑物的情况下，测试了七个1/3比例的钢筋混凝土平板。整个过程都记录了反作用力和挠度，以及钢筋应变和混凝土开裂模式。在动态测试过程中，使用了高速摄像头来捕获动态运动。 ud ud实验表明，通常，平板在失去色谱柱后能够有效地重新分配载荷。尽管观察到很大程度的损坏，但未发生因弯曲破坏而导致的塌陷。但是，由于在相邻的支架上施加了额外的垂直载荷，因此显示出冲剪是一个问题。由于新的荷载路径并非主要通过拆除的立柱位置，因此通过立柱包含连续的底部钢筋并不能显着提高承载能力。结果还表明，由于在弹性范围内测得的挠度最高达静态情况的1.5倍，因此列突然丢失会产生动态影响。还表明，当包括非线性破坏效应时，动态放大系数（DAF）会降低，这意味着用于平板结构的常规基于代码的设计方法可能过于保守。另外，由于应变速率引起的材料强度的增加被认为是不明显的。
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