SGER/Payload Project to NSF Award CMMI-0324522: Earthquake Hazard Reduction for Critical Facilities

这项探索性研究（SGER）项目的小额赠款将利用美国国家科学基金会资助的项目CMMI-0324522的实验测试装置，该项目名为“预制楼板隔膜抗震设计方法的开发”，该项目于2007年在加州大学圣地亚哥分校（UCSD）的NEES室外振动台进行。UCSD NEES振动台通过NSF授予NEES Consortium，公司CMMI-0402490，作为共享使用设施运行。知识优势：该项目解决了与关键子系统（即医院、数据和通信中心的设备隔离系统（EIS））的地震保护相关的三个问题：(1)在近断层地震动和远断层地震动情况下，滚摆式隔震系统对易碎设备的最大抗震保护等级是多少？(2)滚动EIS对近断层地震动大位移需求的敏感性如何？(3)弹性体或摩擦阻尼能否有效衰减有效载荷加速度和隔离器漂移？非结构系统，特别是电信设备，对地震的影响特别脆弱。为了减轻地震给冲击和振动敏感设备带来的风险，数百个数据中心、医院和应急响应中心都安装了隔离系统。典型地，这些EIS是摩擦摆或滚摆式的，由一组包含硬钢球的浅钢盘组成。滚动EIS在低水平地震事件中表现非常好。然而，目前此类设备保护系统的地震鉴定标准不要求长周期激励，因此这些系统在这种载荷下的地震风险是未知的。NEES UCSD长周期、高速振动台和大型、多层、预制混凝土试验结构将由项目0324522建造，为调查这种地震风险提供了经济有效的机会和技术能力。预制混凝土结构将成为测试高速脉冲运动下各种设备滚动隔离系统的主体结构。通过将环境影响系统放置在预制混凝土结构的附近或顶层，环境影响系统将在真实的地板运动下进行测试，包括长时间和高速下的线性和非线性动态放大效应。输入运动将包括选定的历史和/或合成时间历史，具有适当的时间和缩放幅度因子。更广泛的影响：该项目将为杜克大学的工程课程和北卡罗来纳中央大学的新科学计算项目开发课程材料。PI将与几个组织合作，将研究成果纳入实践。根据在http://www.nees.org上发布的数据存档和共享政策，本项目获得的实验数据将存档到NEES中央数据存储库中。该奖项是国家减少地震灾害计划的一部分。

This Small Grant for Exploratory Research (SGER) project will utilize the experimental test set-up of the NSF-funded project CMMI-0324522 entitled "Development of a Seismic Design Methodology for Precast Floor Diaphragm" at the NEES outdoor shake table at the University of California, San Diego (UCSD) during 2007. The UCSD NEES shake table is operated as a shared use facility through NSF award CMMI-0402490 to NEES Consortium, Inc.Intellectual Merit: This project addresses three questions related to the seismic protection of critical subsystems, i.e., equipment isolated systems (EIS) found in hospitals, data, and communication centers: (1) What is the maximum level of seismic protection that rolling-pendulum type isolated systems can provide to fragile equipment for near-fault ground motions and far-fault motions? (2) What is the sensitivity of rolling EIS to the large displacement demands of near-fault ground motions? (3) Can elastomeric or frictional damping effectively attenuate payload accelerations and isolator drift? Nonstructural systems, telecommunications equipment in particular, can be particularly fragile to seismic effects. To mitigate the seismic risk posed to shock and vibration-sensitive equipment, isolation systems have been installed within hundreds of data centers, hospitals, and emergency response centers. Typically these EIS are of a friction pendulum, or rolling-pendulum type, and consist of sets of shallow steel dishes containing a hard steel ball. Rolling EIS perform extremely well during low-level seismic events. Current seismic qualification standards for such equipment protection systems, however, do not require long-period excitation and hence the seismic risk of these systems under this loading is unknown. The NEES UCSD long-period, high-velocity shake table and the large-scale, multi-story, precast concrete test structure to be built by project 0324522 provide a cost-effective opportunity and the technical capability to investigate this seismic risk. The precast concrete structure will be the host structure for testing various equipment rolling isolation systems subjected to high-velocity pulse motions. By placing the EIS near or on the top level of the precast concrete structure, the EIS will be tested under realistic floor motions, including linear and nonlinear dynamic amplification effects at long periods and high velocities. Input motion will include selected historic and/or synthetic time histories, with appropriate time and scaling amplitude factors.Broader Impacts: This project will develop curricular materials for an engineering course at Duke University and for the new Scientific Computation program at North Carolina Central University. The PI will work with several organizations for incorporation of the research results into practice. The experimental data derived from this project will be archived in the NEES central data repository in accordance with data archiving and sharing policies posted at http://www.nees.org. This award is part of the National Earthquake Hazards Reduction Program.