Rolling Isolation Systems to Protect Building Contents from Earthquakes

滚动隔离系统可保护建筑物免受地震影响

• 批准号: 1436015
• 负责人: Henri Gavin
• 金额: $ 24.01万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1436015&HistoricalAwards=false
• 关键词: Rolling; Isolation; Systems; Protect; Building

Fragile objects and mission-critical building contents such as hospital equipment may be placed on rolling isolation systems in order to protect them from damage during earthquake event. Rolling isolation systems consist of a matched pair of horizontal rectangular frames with rigid shallow dishes fixed to their corners. The dishes in the lower frame are concave up, and those in the upper frame are concave down. A large steel ball located between these dishes allows the upper frame to roll over the lower frame. The intensity of shaking that rolling isolation systems can protect against is determined largely by the diameter of the steel dishes. Currently one of the limiting factors for rolling systems is that they can protect objects only from horizontal shaking. Further, the best bowl shape and the proper amount of energy-damping for a particular application remain open questions. This award supports research to develop rolling isolation systems that can protect fragile building contents from severe horizontal and vertical motions. The resulting systems will incorporate specialized components for vertical isolation and multiple isolation layers. In developing these systems and assessing their promise for earthquake hazard mitigation, this research will lead to a better understanding of the true three-dimensional aspect of earthquake ground motions and their impact on fragile objects and structures. Ultimately, the proper design and implementation of rolling isolation will ensure that irreplaceable objects, critical hospital and telecommunications equipment, and digital infrastructure will remain operational during and after severe earthquakes, thereby mitigating the costs of these potentially disastrous events. Research opportunities for undergraduate and high school students will broaden the participation in this research. An industrial-outreach program will enhance the practical dissemination of the results. The non-holonomic constraints inherent to rolling isolation systems result in nonlinear coupling between lateral and rotational dynamics. Uniaxial and linearized models are therefore not sufficient to predict the response of these systems. The objective of this project is therefore to advance the performance and implementation of high-capacity isolation systems for equipment and components subjected to three-dimensional ground-motions. New mathematical models for the nonlinear dynamics of three-dimensional isolation systems will be derived and validated with experiments on a six degree of freedom shake table. These validated models will accelerate the design of new bowl topologies in order to maximize the effective displacement capacities of these systems. New methods of seismic hazard analysis will be developed that recognize the three-dimensional nature of ground motions and the threshold-sensitive behavior of buildings and contents.

易碎物体和关键任务建筑物内容，如医院设备，可以放置在滚动隔离系统，以保护它们在地震事件中免受损坏。 滚动隔震系统由一对匹配的水平矩形框架组成，框架的角上固定有刚性浅盘。 下框内的碗碟向上凹，上框内的碗碟向下凹。 一个位于这些盘子之间的大钢球允许上框架在下框架上滚动。滚动隔震系统可以防止的震动强度主要取决于钢盘的直径。 目前，滚动系统的限制因素之一是它们只能保护物体免受水平震动。 此外，对于特定的应用，最佳的碗形状和适当的能量阻尼量仍然是悬而未决的问题。 该奖项支持研究开发滚动隔离系统，可以保护脆弱的建筑物免受严重的水平和垂直运动。 由此产生的系统将包括用于垂直隔离和多个隔离层的专用组件。 在开发这些系统和评估其对减轻地震灾害的承诺，这项研究将导致更好地了解地震地面运动的真实三维方面及其对脆弱物体和结构的影响。 最终，滚动隔离的正确设计和实施将确保不可替代的物体，关键的医院和电信设备以及数字基础设施在严重地震期间和之后保持运行，从而减轻这些潜在灾难性事件的成本。 本科生和高中生的研究机会将扩大参与这项研究。 一个工业推广方案将加强成果的实际传播。 滚动隔振系统固有的非完整约束导致了横向动力学和旋转动力学之间的非线性耦合。因此，单轴和线性化模型不足以预测这些系统的响应。 因此，本项目的目标是提高性能和实施的高容量的隔离系统的设备和组件受到三维地面运动。本文将推导三维隔震系统非线性动力学的新数学模型，并在六自由度振动台上进行试验验证。 这些经过验证的模型将加速新碗拓扑结构的设计，以最大限度地提高这些系统的有效排量。 将开发新的地震危险性分析方法，认识到地面运动的三维性质以及建筑物和内容的阈值敏感行为。