Collaborative Research: An Innovative Gap Damper to Control Seismic Isolator Displacements in Extreme Earthquakes

该研究项目将研究一种特殊的间隙阻尼器的使用，该阻尼器旨在限制过度变形而不引起冲击以及相关的高频运动和加速。在建筑基础隔震系统的设计中，必须允许隔震器产生较大的变形。同时，这种变形必须加以控制，以避免在罕见但可能发生的强地面运动中达到位移极限而对结构造成破坏。该项目包括高级分析和数值模拟研究，以确定所需性能的最佳间隙阻尼器特性，例如间隙单元的尺寸、间隙前后隔震系统的刚度比以及在不引起建筑物大的加速度的情况下减少位移的能量耗散需求。奥本大学结构研究实验室将对独立阻尼器进行实验研究，以表征阻尼器的耗能性能。雷诺内华达大学大型结构实验室的振动台研究将验证拟议的间隙阻尼器方案的有效性。这项研究将提供一个经过实验和分析验证的框架，从而为不同地震场景下的建筑提供可靠的基于性能的隔震设计。该研究项目预计将导致更好的基础隔震系统的设计，这些隔震系统通常用于关键或必要的设施，如医院、紧急操作中心、消防站和其他重要建筑。研究成果将通过在技术期刊上发表、在专业会议上发表演讲和为该项目创建的网站广泛传播，以便实际实施。实验数据将被存档在乔治·E·布朗地震工程模拟数据库中，以便于地震工程界的其他研究人员访问。该项目将通过参与项目研究活动为研究生和本科生提供高级培训。为了提高对地震工程的认识和重要性，将建立一个“地震工程侦察教育计划”，由几名来自代表性不足的团体的本科生参加下一次大地震后的地震侦察任务。这种参与有望为学生提供一次改变一生的经历，并激励他们长期致力于地震工程。

This research project will study the use of a special gap damper that is designed to limit the excessive deformation without causing impact and the associated high frequency motions and accelerations. In the design of a seismic base isolation system for a building, an isolator must be allowed to deform a significant amount. At the same time, this deformation must be controlled to avoid structural damage due to its reaching the displacement limit in a rare but possible strong ground motion. The project involves advanced analytical and numerical simulation studies to determine the optimal gap damper characteristics for desired performance such as the size of gap element, the ratio of pre- and post-gap isolation system stiffness, and the energy dissipation demand to reduce displacements without inducing large accelerations in the building. Experimental studies on a standalone damper will be conducted in the Structural Research Laboratory at Auburn University to characterize the energy dissipation properties of the damper. Shaking table studies at the Large Scale Structures Laboratory at the University of Nevada, Reno will validate the effectiveness of the proposed gap damper scheme. This study will provide an experimentally and analytically validated framework leading to reliable performance-based isolator design of buildings under different seismic scenarios.This research project is expected to lead to better designs of base isolation systems that are often used in critical or essential facilities such as hospitals, emergency operation centers, fire stations, and other important buildings. The research results will be broadly disseminated for practical implementation to practitioners through publication in technical journals, presentations in professional conferences and the website created for the project. The experimental data will be archived on the George E. Brown Network for Earthquake Engineering Simulation data repository for easy accessibility by other researchers in the earthquake engineering community. The project will provide advanced training to graduate and undergraduate students through their involvement in project research activities. To enhance the awareness and importance of earthquake engineering, a ?Reconnaissance Education Program" will be established with participation of several upper level undergraduate students with representation from underrepresented groups in an earthquake reconnaissance mission after the next major earthquake. This participation is expected to provide a life-changing experience for the students and to motivate them for long-term commitment to earthquake engineering.