Natural Hazards Engineering Research Infrastructure: Upgrade of the Large High Performance Outdoor Shake Table to Six Degrees of Freedom

自然灾害工程研究基础设施：大型高性能户外振动台升级至六自由度

• 批准号: 1840870
• 负责人: Joel Conte
• 金额: $ 1630万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Cooperative Agreement
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-10-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1840870&HistoricalAwards=false
• 关键词: Natural; Hazards; Engineering; Research; Infrastructure

The large, high-performance, outdoor shake table (LHPOST) experimental facility at the University of California, San Diego, is the largest facility of its kind in the United States for conducting earthquake engineering research on civil infrastructure, and has the world's largest payload capacity (20 MN). Because there are no overhead height restrictions, this facility can accommodate the tallest structures ever tested on any shake table. The LHPOST, originally designed to accommodate six degrees of freedom (6DOF), was supported for construction during 2002-2004 as a single degree of freedom (SDOF) system, by the National Science Foundation (NSF), Network for Earthquake Engineering Simulation (NEES), Major Research Equipment and Facilities Construction account, due to budgetary constraints. As an SDOF system and a multi-user national research facility, the LHPOST has been supported by NSF for operations and maintenance under the NEES (FY 2005-FY 2014) and the Natural Hazards Engineering Research Infrastructure (NHERI) (FY 2015 to date) programs. This award will upgrade the LHPOST from its current SDOF configuration to a full 6DOF capability. In its upgraded configuration, the LHPOST will be able to reproduce all six components of motion (two horizontal and vertical translational components, as well as pitch, roll, and yaw rotational components) experienced by the ground during earthquakes. It will provide a one-of-a-kind facility to test large to full size civil infrastructure, such as structural, nonstructural, geo-structural and soil-foundation-structural systems, under strong earthquake excitation. The ability to test infrastructure under the full range of combined horizontal, vertical, and rotational seismic input motion is critical for research that can lead to effective, economical,and practical new infrastructure designs, as well as seismic rehabilitation and retrofit strategies for existing infrastructure, to improve the seismic performance for post-earthquake resilience, public safety, and national welfare. The 6DOF LHPOST will provide critical landmark datasets to support the development, calibration, and validation of high-fidelity, physics-based computational models of civil infrastructure systems that will progressively shift the current reliance on physical testing to model-based simulation for the seismic design and performance assessment of such systems. The experimental capabilities provided by the 6DOF LHPOST will support U.S. leadership in earthquake engineering research. The upgraded shake table will also provide a unique tool to educate graduate, undergraduate, and K-12 students, as well as the news media, policy makers, infrastructure owners, insurance providers, and the public, about natural disasters and the national need to develop effective technologies and policies to prevent earthquakes from becoming societal disasters. This award supports the National Earthquake Hazards Reduction Program (NEHRP). The upgrade of the LHPOST to 6DOF will be achieved by adding two horizontal actuators and reconfiguring all four horizontal actuators into a V-shape at both longitudinal ends of the shake table's 12.2 meter long by 7.6 meter wide platen to provide bi-axial horizontal motions, as well as the yaw motion capabilities. Each of the existing six pressure balanced vertical actuators/bearings will be equipped with a high-flow servovalve to enable vertical, pitch, and roll motion capabilities. To operate the 6DOF table, the number of hydraulic power units will be increased from two to four and the total size of the accumulator banks will be increased from 9,500 to 37,800 liters. A new piping system will be installed between the accumulator banks, the horizontal and vertical actuators, and the surge tank. A third nitrogen-filled hold-down strut will be installed between the bottom of the platen and the bottom of the reaction block to increase the overturning moment capacity of the table. The existing SDOF shake table controller (both hardware and software) will be replaced by a controller with 6DOF capabilities. A new hydraulic distribution system controller will also be provided to handle the safety interlocks, control of the hydraulic power units, and control of the accumulator charging and blowdown. Additionally, the height of the existing four safety towers will be doubled to protect the hydraulic power building from potential specimen collapse. During the upgrade, operations of the shake table under NHERI will cease for a period of 14 months between mid-2020 and mid-2021. Before reopening the facility for operations and research, commissioning of the facility, including acceptance and characterization tests, will be performed.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.

加州大学圣地亚哥分校的大型高性能户外振动台（LHPOST）实验设施是美国最大的民用基础设施地震工程研究设施，拥有世界上最大的有效载荷容量（20 MN）。 由于没有架空高度限制，该设施可以容纳在任何振动台上测试过的最高结构。 LHPOST 最初设计用于容纳六自由度 (6DOF)，并在 2002 年至 2004 年期间作为单自由度 (SDOF) 系统得到了美国国家科学基金会 (NSF)、地震工程模拟网络 (NEES) 的支持），主要研究设备设施建设账户，由于预算限制。作为一个 SDOF 系统和一个多用户国家研究设施，LHPOST 得到了 NSF 的支持，用于 NEES（2005 财年至 2014 财年）和自然灾害工程研究基础设施（NHERI）（2015 财年至今）下的运营和维护程序。 该合同将 LHPOST 从当前的 SDOF 配置升级为完整的 6DOF 功能。在升级后的配置中，LHPOST 将能够再现地震期间地面所经历的所有六个运动分量（两个水平和垂直平移分量，以及俯仰、滚动和偏航旋转分量）。它将提供一种独一无二的设施，用于在强地震激励下测试大型至全尺寸的民用基础设施，例如结构、非结构、地质结构和土壤基础结构系统。在全方位组合的水平、垂直和旋转地震输入运动下测试基础设施的能力对于研究至关重要，可以导致有效、经济和实用的新基础设施设计，以及现有基础设施的地震修复和改造策略，提高抗震性能，促进震后恢复、公共安全和国家福利。 6DOF LHPOST 将提供关键的地标数据集，以支持民用基础设施系统的高保真、基于物理的计算模型的开发、校准和验证，这将逐步将当前对物理测试的依赖转变为基于模型的抗震设计模拟以及此类系统的性能评估。 6DOF LHPOST 提供的实验能力将支持美国在地震工程研究方面的领导地位。升级后的摇表还将提供一个独特的工具，向研究生、本科生和 K-12 学生以及新闻媒体、政策制定者、基础设施所有者、保险提供商和公众提供关于自然灾害和国家需要的教育。制定有效的技术和政策，防止地震成为社会灾难。该奖项支持国家地震减灾计划（NEHRP）。 LHPOST 升级至 6DOF 将通过添加两个水平执行器并将所有四个水平执行器重新配置为振动台 12.2 米长、7.6 米宽压板纵向两端的 V 形来实现，以提供双轴水平运动，以及偏航运动功能。现有的六个压力平衡垂直执行器/轴承中的每一个都将配备一个高流量伺服阀，以实现垂直、俯仰和滚动运动功能。为了操作 6DOF 工作台，液压动力装置的数量将从两个增加到四个，蓄能器组的总容量将从 9,500 升增加到 37,800 升。新的管道系统将安装在蓄能器组、水平和垂直执行器以及缓冲罐之间。第三个充氮压紧支柱将安装在压板底部和反应块底部之间，以增加工作台的倾覆力矩能力。现有的 SDOF 振动台控制器（硬件和软件）将被具有 6DOF 功能的控制器取代。还将提供一个新的液压分配系统控制器来处理安全联锁、液压动力装置的控制以及蓄能器充电和排污的控制。此外，现有四个安全塔的高度将增加一倍，以保护水力发电建筑免受潜在的样本倒塌的影响。升级期间，NHERI 下的摇床运行将在 2020 年中期至 2021 年中期停止 14 个月。在重新开放该设施进行运营和研究之前，将对该设施进行调试，包括验收和特性测试。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

NHERI@UC San Diego 6-DOF Large High-Performance Outdoor Shake Table Facility

NHERI@加州大学圣地亚哥分校 6 自由度大型高性能户外振动台设施

• DOI: 10.3389/fbuil.2020.580333
• 发表时间: 2021
• 期刊: Frontiers in Built Environment
• 影响因子: 3
• 作者: Van Den Einde, Lelli;Conte, Joel P.;Restrepo, José I.;Bustamante, Ricardo;Halvorson, Marty;Hutchinson, Tara C.;Lai, Chin-Ta;Lotfizadeh, Koorosh;Luco, J. Enrique;Morrison, Machel L.
• 通讯作者: Morrison, Machel L.