Low-Damage Seismic Solutions for Structural Systems with Wood

木材结构系统的低损伤抗震解决方案

• 批准号: RGPIN-2017-06561
• 负责人: Iqbal, Asif
• 金额: $ 1.46万
• 依托单位: University of Northern British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=764697
• 关键词: Low; Damage; Seismic; Solutions; Structural

In typical seismic design approach, damages during a major earthquake are considered acceptable as long as life safety is achieved. But significant financial losses in recent earthquakes have raised questions about performance of structures in terms of post-earthquake recovery cost and time. One alternative approach termed “Low-damage Solution”, which avoids damage to the main structural members by allowing damages in sacrificial elements within the system, has attracted significant interest from designers, planners and the community. Provisions are also made to replace the damaged elements after a major earthquake and bring the structure back to a fully functional level within a short period of time at a reasonable cost. One of the most well-known mechanisms that applies the low-damage philosophy involves the combination of unbonded post-tensioning and mild steel-yielding elements. The post-tensioning tendons are essentially elastic metal strands that run through the structural members holding them together, thereby ensuring integrity and full self-centering of the assembly following an earthquake. The mild steel elements located at connections absorb energy through significant inelastic deformations, in turn protecting the main structural members from damage.Over the last decade, the concept has been successfully implemented with structural members made of engineered wood products through extensive research and a number of applications, mostly in New Zealand. The technology has recently been imported to North America, (known as post-tensioned' wood structures) where it is financially competitive only for high-rise (up to 14 stories) wood buildings. But very limited information is currently available on structural systems for wood buildings beyond six stories in general. The two regions of both Canada and the United States most likely to have tall wood buildings also have significant seismic risks. This underlines the need for comprehensive research on structural systems, i.e. assemblies of members, for tall wood buildings. This research program will explore building structural systems that are most likely to be suitable for the 8 to 14 storied height range. The proposed systems are: frames with cross-bracings, frames in combination with individual or multiple walls, and Hybrid structures, i.e. combination of wood with concrete and/or steel. Attempts will be made to develop practical guidelines and details for all the systems to promote widespread applications.The benefits to my field and Canada will be two-fold: first, the new understandings and expectations for better seismic performance of structures will eventually help improved standards of design practice ensuring better life safety; and secondly, the new knowledge will advance the country's standing in terms of wood construction, leading to potential growth in the forestry sector and ensuing economic benefits.

在典型的抗震设计方法中，只要能保证生命安全，大地震造成的破坏是可以接受的。 但是，在最近的地震中，重大的经济损失引起了人们对地震后恢复成本和时间方面的结构性能的质疑。一种称为“低损伤解决方案”的替代方法，通过允许系统内牺牲元件的损伤来避免对主要结构构件的损伤，引起了设计者、规划者和社区的极大兴趣。还规定在发生大地震后更换损坏的构件，并以合理的费用在短时间内使结构恢复完全功能。应用低损伤原理的最著名的机制之一涉及无粘结后张拉和软钢屈服元件的组合。后张预应力筋基本上是弹性金属股，其贯穿将它们保持在一起的结构构件，从而确保地震后组件的完整性和完全自定心。位于连接处的低碳钢构件通过显著的非弹性变形吸收能量，从而保护主要结构构件免受损坏。在过去的十年中，通过广泛的研究和大量的应用，该概念已成功地应用于由工程木制品制成的结构构件，主要在新西兰。该技术最近被引进到北美（称为后张“木结构”），在那里它只在高层（最高14层）木建筑中具有经济竞争力。但是，目前关于一般六层以上木结构建筑的结构系统的信息非常有限。加拿大和美国的两个地区最有可能拥有高大的木结构建筑，也有很大的地震风险。这就强调了对高层木结构建筑的结构系统，即构件组件进行全面研究的必要性。该研究计划将探索最有可能适用于8至14层高度范围的建筑结构系统。拟议的系统是：带交叉支撑的框架、与单个或多个墙壁组合的框架以及混合结构，即木材与混凝土和/或钢的组合。将努力为所有系统制定实用的指导方针和细节，以促进广泛的应用。对我所在的领域和加拿大的好处将是双重的：首先，对结构更好的抗震性能的新理解和期望最终将有助于提高设计实践的标准，确保更好的生命安全;其次，新知识将提高该国在木结构方面的地位，从而促进林业部门的潜在增长，并带来经济效益。