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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=677203
• 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，只要达到生命安全，在大地震期间的破坏被认为是可以接受的。但在最近的地震中，巨大的经济损失引发了人们对结构在震后恢复成本和时间方面的性能的质疑。另一种被称为“低损害解决方案”的方法，通过允许系统内牺牲元素的损害来避免对主要结构构件的损害，引起了设计者、规划者和社区的极大兴趣。还规定在大地震后更换损坏的部件，并以合理的费用在短时间内将结构恢复到完全功能的水平。最广为人知的应用低损伤理念的机制之一涉及无粘结后张拉和轻钢屈服元素的组合。后张拉筋本质上是弹性金属绞线，贯穿将它们连接在一起的结构构件，从而确保地震后装配的完整性和完全的自我定心。位于连接处的软钢元件通过显著的非弹性变形吸收能量，进而保护主要结构构件免受损坏。*在过去十年中，通过广泛的研究和大量应用，这一概念已成功应用于由工程木制品制成的结构构件，主要是在新西兰。这项技术最近被引进到北美(称为后张拉木结构)，在那里，只有高层(最多14层)的木结构建筑才具有经济竞争力。但目前有关六层以上木结构建筑结构体系的信息非常有限。加拿大和美国最有可能拥有高大木结构建筑的两个地区也存在严重的地震风险。这突出表明需要对高层木结构建筑的结构系统，即构件的装配进行全面研究。该研究项目将探索最适合8到14层高度范围的建筑结构体系。建议的体系是：带交叉支撑的框架，单独或多个墙组合的框架，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。*对我的领域和加拿大将有两方面的好处：第一，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；第二，新的知识将提高该国在木结构方面的地位，导致林业部门的潜在增长和随之而来的经济效益。