NEESR-GC: Mitigation of Collapse Risk in Vulnerable Concrete Buildings

这个多机构奖是NSF 06-504计划征求“乔治E。小布朗地震工程模拟研究网络（NEESR）竞赛。 在美国，最大的整体地震风险之一是旧混凝土建筑物在大城市地震中倒塌的风险，但没有解决方案如何以具有成本效益的方式解决这个问题。 政策制定者和建筑业主对改造现有建筑的大量库存的成本感到沮丧。工程师需要工具来准确评估单个建筑物的风险，并区分适当的建筑物和潜在的危险建筑物，以便建筑业主可以优先考虑缓解费用。监管机构需要更好地了解风险的区域范围，以便制定有效的政策措施，实现区域缓解努力。该项目将研究普遍存在和高风险的旧非韧性混凝土建筑物的倒塌可能性，以改进和传播有效的工程评估和改造工具，并确定适当的激励措施或政策措施，以减轻风险。 研究将探讨四个方面：1）暴露-选择一个单一的城市区域作为其他区域的模型，并开发适用于研究旧型混凝土建筑物区域倒塌风险的库存模型; 2）组件和系统性能-将对组件、传感器和系统进行实验室和现场实验，和土壤-基础-结构系统，以更好地了解导致倒塌的条件; 3）建筑和区域模拟-模型将在对地震工程师有用的非线性动态分析软件中开发和实施，并透过区域动态模拟，将结果加以推广，以协助了解大地震中建筑物倒塌的区域分布;缓解战略-有效的缓解战略和包括工程师、规划人员、政策专家在内的联盟，和利益相关者将被开发，以促进减少风险的行动。该计划的特点是一个重要的教育组成部分，旨在增加地震工程的多样性，国际合作，并推广到广泛的社区传播成果。智力价值在于理解三维荷载下倒塌的条件和力学的多学科挑战，在软件中实现可用于单个建筑物分析的理解，并将理解扩展到区域层面，工程科学、经济学和公共政策之间的交叉将为推荐最佳缓解策略提供合理的基础。该研究计划解决了一个重要而具有挑战性的问题，这将促进对地震工程的发现和理解。该教育计划将使多样化的本科生群体参与该计划，并促进顶尖候选人进入研究生研究。 研究结果将通过多种方式传播，包括：通过使用NEES资源共享结果，通过让地震专业人员和城市规划人员参与，以及通过传播教育材料。研究结果将有助于确定适当的工程和公共政策解决方案，以解决现有的危险建筑施工问题，从而造福社会。更好地了解地震期间建筑物的倒塌情况也将有助于了解基础设施的脆弱性和加固能力，以抵御爆炸和撞击危险的影响。本项目中制定的减灾战略也可以为飓风等其他自然灾害的减灾战略提供信息。 该项目使用位于伯克利的加州大学、洛杉矶的加州大学、圣巴巴拉的加州大学和明尼苏达大学的NEES设备站点。

This multi-institution award is an outcome of the NSF 06-504 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation Research (NEESR)" competition. One of the greatest overall seismic risks in the United States is the risk of collapse of older concrete buildings in a major urban earthquake, yet there are no solutions to how to address this in a cost-effective manner. Policy makers and building owners are frustrated by the costs of retrofitting large inventories of existing buildings. Engineers need tools to accurately assess the risk of individual buildings and to differentiate between adequate buildings and potentially hazardous ones, so building owners can prioritize mitigation expenses. Regulatory agencies need better information on the regional extent of the risk so that effective policy measures can be put in place to effect regional mitigation efforts. This project will study the collapse potential of older nonductile concrete buildings, which are pervasive and high risk, to improve and disseminate effective engineering assessment and retrofit tools and to define appropriate incentive or policy measures to mitigate the risk. The research will investigate four areas: 1) Exposure - a single urban region will be selected to serve as a model for other regions, and an inventory model suitable to study the regional collapse risk of older type concrete buildings will be developed; 2) Component and System Performance - laboratory and field experiments will be conducted on components, subassemblies, and soil-foundation-structure systems to better understand conditions that lead to collapse; 3) Building and Regional Simulation - models will be developed and implemented in nonlinear dynamic analysis software useful to earthquake engineers, and results will be extended through regional dynamic simulations to help understand the regional distribution of building collapses in a major earthquake; and 4) Mitigation Strategies - effective mitigation strategies and coalitions involving engineers, planners, policy experts, and stakeholders will be developed to promote action for risk reduction. The program features a significant education component aimed at increasing diversity in earthquake engineering, international collaborations, and outreach to disseminate results to a broad community.The intellectual merit lies in the multi-disciplinary challenge of understanding the conditions and mechanics of collapse under three-dimensional loading, implementing that understanding in software usable for individual building analysis, and extending the understanding to the regional level where the intersection among engineering science, economics, and public policy will provide a rational basis for recommending the best mitigation strategies.The broader impacts of the project are extensive. The research program tackles an important and challenging problem that will advance discovery and understanding of earthquake engineering. The education program will expose a diverse population of undergraduates to the program and promote top candidates into graduate research. The results of the research will be disseminated in several ways, including: by sharing results using the NEES resources, by involving earthquake professionals and urban planners, and by disseminating educational materials. The results will benefit society by helping define appropriate engineering and public policy solutions to address the problem of existing hazardous building construction. Better understanding collapse of buildings during earthquake will also contribute to knowledge on vulnerability and toughening of infrastructure against effects of explosive and impact hazards. Mitigation strategies developed in this project also can inform strategies to mitigate for other natural hazards such as hurricanes. This project uses the NEES equipment sites at the University of California, Berkeley, the University of California, Los Angeles, the University of California, Santa Barbara, and the University of Minnesota.