Behaviour of composite floor plates during the cooling phase of a fire

总结了解建筑物在火灾期间的结构行为对于充分利用最近推出的基于性能的设计规范是必不可少的。然而，目前人们对建筑物在火灾冷却阶段的行为知之甚少。来自全尺寸测试和真实火灾的证据表明，建筑物可能在火灾冷却阶段发生倒塌，这可能危及消防员和建筑物附近公众的安全。曼彻斯特大学和爱丁堡大学的这个联合项目将调查冷却钢-混凝土组合结构的行为，以了解它们的行为和潜在的机理。该项目包括测试组合板，在不同的轴向约束条件和自然火灾情况下，以获得对火灾冷却阶段结构内产生的力的独特了解。与该项目的试验阶段并行进行的是，现有的数值模型将扩展到模拟冷却阶段的结构行为。一旦得到验证，数值模型将允许了解整个火灾持续时间内完整结构的行为，大大提高当前的建模能力，这些能力集中在火灾估计的最高温度之前的行为。复杂模型的结果，加上实验结果，将允许制定简单的设计规则，以确保建筑物在火灾冷却阶段不会倒塌，从而确保消防员和公众所需的安全水平。

SUMMARYUnderstanding structural behaviour of buildings during a fire is accepted as being essential to make full use of the recently introduced performance-based design codes. However, currently the behaviour of buildings during the cooling phase of a fire is poorly understood. Evidence from full-scale tests and real fires has shown that collapse of buildings can occur during the cooling stage of the fire, which can compromise the safety of firefighters and the public in the proximity of the building. This joint project between Manchester and Edinburgh University, will investigate the behaviour of cooling steel-concrete composite structures to gain an understanding of their behaviour and the underlying mechanics. The project includes testing of composite slabs, subject to different axial restraint conditions and natural fire scenarios, to obtain a unique understanding of forces generated within the structure during the cooling stage of a fire. Working in parallel to the experimental phase of the project, existing numerical models will be extended to simulate structural behaviour during the cooling phase. Once validated, the numerical models will allow an understanding of the behaviour of complete structures during the full duration of the fire, significantly advancing the current modelling capabilities which concentrate on the behaviour up to the fire's estimated maximum temperature. The results from the complex models, together with the experimental results, will allow simple design rules to be developed to ensure that buildings do not collapse during the cooling stage of the fire, thus ensuring the required level of safety for both firefighters and the public.