Collaborative Research: Assessment of Building Resiliency in Tornadoes Considering Transient Internal Pressure Effects

在自然灾害（包括龙卷风）发生后，作为社区基本设施的建筑物必须保持运转，以提供重要服务并缩短恢复时间。建筑物在龙卷风中倒塌的一个常见原因是建筑物外壳突然出现大开口，例如当头顶的车门因碎片撞击而破裂时。这些突然的裂缝造成建筑物内部压力的突然变化，进而产生额外的结构效应。但迄今为止，对这类压力变化的研究还不多。这个灾害恢复研究拨款（DRRG）项目将量化短暂的内部压力和变化的影响，以改进对龙卷风中可能的建筑性能的评估。研究结果将对包括关键基础设施和其他类型建筑物在内的抗龙卷风建筑设计规范和标准的制定做出重大贡献。此外，来自研究的数据将在自然灾害工程研究基础设施（NHERI）的数据仓库中进行管理，供开放访问，以告知其他关于建筑物龙卷风荷载的研究。透过与学者和专业人士就结构工程的抗灾能力举行专题研究研讨会，该计划将加强学术界与业界的伙伴关系。一项指导计划将支持被认为是结构工程中代表性不足群体成员的本科生，教育推广活动将提高社区对龙卷风危害的认识。这项研究的目的是提高对建筑物内部压力的理解，因为建筑物围护结构突然出现大开口，以便准确评估龙卷风中的建筑物性能。我们的中心假设是，由建筑围护结构中突然出现的大开口引起的瞬态内部压力是显著的，并且对建筑系统的影响与建筑物封闭或预先存在的大开口不同。将开发一个经过龙卷风模拟器测试验证的强大计算模型，该模型的输出将有助于设计对龙卷风事件更具弹性的建筑物。这项研究将通过实现三个具体目标来进行。首先，将基于龙卷风模拟器的实验，对建筑围护结构突然破坏引起的瞬态内压进行量化，并将结果用于验证计算模型。其次，利用验证后的计算模型，在考虑系统固有不确定性的情况下，研究主要开口尺寸和破坏模式对系统强度和弹性的影响。第三，这项工作将产生脆弱性函数和建议，指导工程师如何优化资源以实现龙卷风弹性设计。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Buildings that serve as essential facilities to communities must remain operational after natural disasters, including tornadoes, to provide vital services and reduce recovery time. A frequent cause for building failures in tornadoes has been the sudden occurrence of large openings in the building envelope, such as when overhead vehicular doors are breached due to debris impact. These sudden breaches create sudden changes in the internal pressure of the building which, in turn, yield additional structural effects. But there has not been much research on these sorts of pressure changes to date. This Disaster Resilience Research Grants (DRRG) project will quantify transient internal pressures and the effects of changes in order to improve assessment of likely building performance in tornadoes. Findings will contribute significantly to the development of codes and standards for tornado-resistant building design, including critical infrastructures and other types of buildings. In addition, the data from the research will be curated in the Data Depot repository of the Natural Hazards Engineering Research Infrastructure (NHERI) for open access to inform other research on tornadic loading of buildings. Through dedicated special research symposia on disaster resilience in structural engineering with academics and professionals, the project will enhance partnerships between academia and industry. A mentoring program will support undergraduate students who identify as members of underrepresented groups in structural engineering, and educational outreach activities will improve community tornado hazard awareness.The goal of the study is to improve the understanding of internal pressure of buildings due to sudden occurrences of large openings in the building envelope to enable the accurate assessment of building performance in tornadoes. Our central hypothesis is that transient internal pressure caused by sudden occurrences of large openings in the building envelope is significant and affects the building system differently than when the building is enclosed or has preexisting large openings. A robust computational model validated with testing in a tornado simulator will be developed and output from this model will help enable the design of buildings that are more resilient to tornado events. The research will be carried out by achieving three specific aims. Firstly, transient internal pressure resulting from a sudden failure in the building envelope will be quantified based on experiments in a tornado simulator, and the results will be used to validate computational models. Secondly, the validated computational model will be utilized to study the effects of dominant opening sizes and failure modes on the system strength and resiliency, incorporating inherent system uncertainties. Thirdly, this work will produce fragility functions and recommendations to guide engineers on how to optimize resources to achieve tornado resilient designs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.