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

该探索性研究小额赠款（SGER）项目将利用NSF资助项目CMMI-0324522的实验测试装置，该项目题为“预制楼板隔板抗震设计方法的开发”，2007年在加州大学圣地亚哥分校（UCSD）的NEES室外振动台上进行。 UCSD NEES振动台通过NSF授予NEES Consortium，Inc.的CMMI-0402490作为共享使用设施运行。知识产权：该项目解决了与关键子系统的地震保护相关的三个问题，即，医院、数据中心和通信中心的设备隔震系统（EIS）：（1）对于近断层地震运动和远断层地震运动，滚摆型隔震系统能为脆弱设备提供的最大地震保护水平是多少？ (2)滚动EIS对近断层地震动的大位移需求的灵敏度是多少？ (3)弹性或摩擦阻尼能有效地衰减有效载荷加速度和隔振器漂移吗？ 非结构系统，特别是电信设备，在地震作用下特别脆弱。为了减轻对冲击和振动敏感的设备造成的地震风险，已在数百个数据中心、医院和应急响应中心安装了隔离系统。 典型地，这些EIS是摩擦摆或滚动摆类型的，并且由包含硬钢球的浅钢盘组组成。滚动EIS在低级别地震事件中表现得非常好。 然而，这种设备保护系统的现行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。 项目0324522将建造的NEES UCSD长周期高速振动台和大型多层预制混凝土试验结构为调查这种地震风险提供了具有成本效益的机会和技术能力。 预制混凝土结构将是测试各种设备滚动隔震系统承受高速脉冲运动的主体结构。 通过将EIS放置在预制混凝土结构的顶层附近或顶层上，将在真实的楼板运动下测试EIS，包括长周期和高速度下的线性和非线性动力放大效应。 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：本项目将为杜克大学的工程课程和北卡罗来纳州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http://www.nees.org上发布的数据存档和共享政策，该项目产生的实验数据将存档在NEES中央数据库中。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.