Seismic performance improvement of buildings with self-centering bracings

自定心支撑提高建筑物抗震性能

• 批准号: 570821-2021
• 负责人: Alam, Shahria
• 金额: $ 5.25万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=722939
• 关键词: Seismic; performance; improvement; buildings; self

Bracings are diagonal structural elements in a building for resisting lateral loads. Traditional bracings essentially carry axial loads. They perform well under axial tension. However, under compression, braces tend to buckle and lose their load carrying capacity. Researchers have proposed buckling restrained bracing, yielding bracing, etc to overcome this buckling problem. However, their disadvantages including: a) heavy weight, b) fabrication difficulty, and c) potential permanent damages after an earthquake. Here, novel bracing systems are proposed to overcome these shortcomings. These systems will be light-weight, and will remain operational with no permanent damages even during a large earthquake. The proposed system will utilize superelastic shape memory alloy (SMA) bars installed inside a cylinder piston, or SMA plates in confined rubberized concrete assembly. A properly designed self-centering braced frame structure is expected to remain operational even after a large seismic event due to its self-centering capability, increasing safety and survivability. It will also provide large savings in reduced repair/replacement work necessary in a post-disaster scenario, and potential for remediation in place rather than demolition. The significance of this research is paramount as this novel technology will help Canada improve the level of safety of building infrastructure during earthquakes. The first stage will involve evaluating the mechanical properties of SMA bars/plates and performance of couplers that connect SMA to steel parts. A series of large-scale quasi-static cyclic and dynamics tests will be performed on bracing elements and braced frames. The generated experimental data will be employed to determine the important parameters that affect the seismic response and limit states, which will help develop performance-based design guidelines for braced frames. The proposed design guidelines will be validated with hybrid simulation tests. The research team will work closely with the partners and design code committee to formulate the appropriate framework with which the proposed design recommendations can be incorporated in the design codes.

支撑是用于抵抗横向载荷的建筑物中的对角线结构元素。传统的支撑本质上是轴向负荷。它们在轴向张力下表现良好。但是，在压缩下，牙套倾向于扣紧并失去承载能力。研究人员提出了屈曲的束缚支撑，产生支撑等，以克服这个屈曲问题。但是，它们的缺点包括：a）重量，b）制造难度和c）地震后潜在的永久损害。在这里，提出了新的支撑系统来克服这些缺点。这些系统将是轻量级的，即使在大地震期间，即使在大地震期间也将保持不变。所提出的系统将利用安装在圆柱活塞中的超弹性形状合金（SMA）条，或在密闭的橡胶混凝土组件中使用的SMA板。即使在发生大型地震事件之后，由于其自​​我居中能力，提高安全性和生存能力，预计适当设计的自中心支撑框架结构也将保持运行。它还将为减少修复/替换工作提供大量节省，在灾后场景中必需的修复/更换工作，以及进行补救的潜力而不是拆除。这项研究的重要性至关重要，因为这项新技术将有助于加拿大在地震期间提高建筑基础设施的安全水平。第一阶段将涉及评估SMA条/板的机械性能以及将SMA连接到钢零件的耦合器的性能。一系列大规模的准静态循环和动力学测试将对支撑元素和支撑框架进行。将使用生成的实验数据来确定影响地震响应并限制状态的重要参数，这将有助于制定基于绩效的设计指南。提出的设计指南将通过混合模拟测试验证。研究团队将与合作伙伴和设计代码委员会紧密合作，以制定适当的框架，可以将建议的设计建议纳入设计代码。