CAREER: Multihazard Progressive Collapse Analysis of Structures

摘要：防止建筑物的渐进性倒塌是一个非常重要的社会问题，特别是在最近发生的恐怖袭击事件中。这份职业建议提出了一项分析结构逐步倒塌的综合研究和教育计划。渐进式倒塌是一种系统级现象，初始局部破坏的扩展导致整个结构或其不成比例的大部分倒塌。渐进式抗坍塌工程需要系统级行为的知识，但实际数据很少，因为系统级测试成本高得令人望而却步。这个职业项目将利用创新和低成本的方法来收集、使用和分析预定通过内爆拆除的全尺寸结构的现场数据。具体地说，该署会在批地期间测试及监察五个将会以内爆方式拆卸的钢筋混凝土构筑物的表现。将收集大量新数据，形成减缓渐进性崩塌的框架。这样的努力将是抗倒塌工程和为社会提供安全和坚固的物理基础设施的重要一步。从全尺寸试验收集的数据将用于在系统级倒塌行为的以下领域开发新知识：1)能力：钢筋混凝土(RC)部件和系统的失效标准将被扩展以考虑极端变形、系统效应和速率相关性；2)需求：将评估、验证和改进用于预测失效后响应的分析技术和工具；3)性能：将评估当前渐进倒塌预防的实践，并将开发更可靠的程序；4)多重危险风险：将制定程序，将遭受人为危险的建筑物的潜在渐进倒塌与自然灾害的设计水平联系起来。该项目将把它的研究产品纳入一个全面的教育计划，目标是大学生、工程和建筑从业人员以及高中教师和学生。渐进式崩溃的系统级性质使得必须包括多个学科以及多个层次的理解。该计划将不仅涉及定量工程工具，还将涉及定性概念推理。为了增进这两种类型的理解，该项目将建立在用户友好的计算机程序Arade的基础上。扩展后的程序将能够对结构在倒塌前的反应进行三维分析和可视化。更好地了解和评估用于阻止建筑物逐渐倒塌、改进新建筑物的设计和确定建筑物修复优先次序的机制，可能会挽救无数生命和金钱。大学生将参加一项创新的年度竞赛，以预测小型钢筋混凝土模型的倒塌，并通过使用一种新的计算机程序学习结构的渐进倒塌。该项目还将用于培训建筑师，了解建筑决策对结构安全和倒塌行为的影响。将与一个咨询委员会合作，举办针对工程师和建筑师的讲习班。将开发一个互动网站，以报告研究成果和教育材料。在CESAME和东北RET计划的合作下，该网站和相关的教育材料将被引入高中。该项目将：1)为学生举办年度竞赛，以评估RC系统的物理模型的倒塌；2)为工程师提供结构倒塌分析所需的了解和工具；3)帮助建筑师了解影响连续倒塌的建筑特征；4)开发模块和一个小型单元课程，供大学和中学教授。

Abstract :Preventing progressive collapse in structures is a gravely important problem for society, particularly in light of recent terror attacks. This Career proposal presents an integrated research and education plan for analysis of progressive collapse of structures. Progressive collapse is a system-level phenomenon where the spread of an initial local failure results in the collapse of an entire structure, or a disproportionately large part of it. Progressive collapse resistant engineering requires knowledge of system-level behavior, but there is very little actual data because system-level tests are prohibitively expensive. This Career project will utilize innovative and low-cost methods to collect, use, and analyze field data from full-scale structures slated for demolition by implosion. Specifically, the PI will instrument and monitor the performance of five RC structures to be demolished by implosion during the grant period. A wealth of new data will be collected and form the basis of a framework for mitigating progressive collapse. Such an effort will be a major step forward for collapse resistance engineering and toward providing society with a physical infrastructure that is safe and robust.Data collected from full-scale experiments will be used to develop new knowledge in the following areas of system-level collapse behavior:1) Capacity: Failure criteria for reinforced concrete (RC) components and systems will be expanded to account for extreme deformations, system effects, and rate dependence; 2) Demand: Analytical techniques and tools for predicting post-failure response will be evaluated, verified, and improved; 3) Performance: Current practice for progressive collapse prevention will be evaluated and more reliable procedures will be developed; 4) Multihazard risk: Procedures will be developed to relate potential progressive collapse of structures subjected to man-made hazards and the design levels for natural hazards. The project will incorporate its research products into a comprehensive education plan targeting university students, practitioners of engineering and architecture, as well as high school teachers and students. The system-level nature of progressive collapse makes it imperative to include multiple disciplines, as well as multiple levels of understanding. The plan will address not only quantitative engineering tools but also qualitative conceptual reasoning. To enhance both types of understanding, the project will build on the user-friendly computer program Arcade. The extended program will be capable of three-dimensional analysis and visualization of response of structures up to collapse. A better understanding and assessment of the mechanisms used to arrest progressive collapse of structures, improving the design of new buildings and prioritizing buildings for rehabilitation may save numerous lives and money. University students will participate in an innovative annual competition for predicting collapse of small-scale RC models and learn about progressive collapse of structures by utilizing a new computer program. The program will also be used to train architects about the impact of architectural decisions on structural safety and collapse behavior. Workshops targeted to engineers and architects will be developed in collaboration with an advisory committee. An interactive website will be developed to report research outcomes and educational materials. In collaboration with CESAME and the Northeastern RET program, the website and related educational material will be introduced to high schools. This project will: 1) Conduct annual competitions for students to evaluate collapse of physical models of RC systems; 2)Provide engineers with the required understanding and tools for collapse analysis of structures; 3)Help architects learn about building characteristics affecting resistance to progressive collapse; 4) Develop modules and a mini-unit course to be taught in universities and high schools..