测试强调高质量木材的抗震弹性
Jun 16, 2023 WoodWorks
Key Takeaways
- In May, a 10-story building made of cross-laminated timber (CLT) underwent testing on the world’s largest outdoor shake table at the University of California San Diego. The goal? 验证大型木结构高层建筑的抗震能力.
- This project could pave the way for changes in building codes for residential and commercial structures that could lead to more widespread adoption of mass timber—especially in areas prone to seismic activity.
- It could also validate mass timber and other innovative technologies as vehicles to help make buildings safer and more resistant to earthquake activity.
- WoodWorks has resources and education available to get you up to speed on what this means for mass timber building design.
10层NHERI振动台试验:大型木材抗震设计的最新进展
On May 9th, a 10-story building made of cross-laminated timber underwent testing on the world’s largest outdoor shake table, 由国家科学基金会(NSF)资助, 在加州大学圣地亚哥分校(UCSD). The structure was constructed to undergo testing as part of the Natural Hazards Engineering Research Infrastructure (NHERI) TallWood Project, an industry-wide initiative that investigates the seismic resilience of mass timber and the extent of its potential use as a low-carbon structural material.
这次考试是一长串大学之间多年合作的高潮, industry partners, design and construction partners, 以及包括WoodWorks在内的非营利合作伙伴, Think Wood, the Softwood Lumber Board (SLB) and the Binational Softwood Lumber Council (BSLC)—who have worked together to further mass timber innovation. The principal investigators include researchers from the Colorado School of Mines; the University of Washington; the University of Nevada, Reno; Colorado State University; Washington State University; and Lehigh University.
“大量木材已经被全球认为是可持续的, low-carbon building material,” shared Cees de Jager, President and CEO of the SLB and BSLC. “这些测试将证明大量木材作为安全有效的建筑的可行性, as well as sustainable, 在地震活跃地区替代钢筋混凝土建筑, 为在全国范围内更广泛地采用高层木结构铺平了道路.”
The UCSD shake table, where the testing is taking place, recently underwent an upgrade that increased the number of axes of shake—allowing it to better simulate actual seismic events. 采用大量木材岩壁系统, the structure was designed to withstand high-magnitude earthquakes and incur little to no structural damage. In the initial tests, the building underwent simulations of two of the most destructive earthquakes in recent history. The first test was equivalent to the 6.1994年北岭7级地震,第二次到7级.1999年发生在台湾的7级赤赤地震. 在每次模拟之后,研究人员评估了建筑物的损坏情况.
In an interview with UCSD, Shiling Pei, associate professor at Colorado School of Mines and lead investigator on the NHERI Tallwood Project, said, “It performed exactly as we expected—the building remained damage free after two major design-level earthquakes back to back.”
Engineering News Record details 岩墙系统的技术成果, talking with Reid Zimmerman, 波特兰结构技术总监, OR office of KPFF Consulting Engineers, 也是TallWood设计和施工团队的一员. “For post-tensioning, 每一面摇摆的墙壁上都有两根高强度的螺纹杆, 哪种预压缩CLT板或大质量胶合板. 在墙的底部,杆子锚定在地基上. At the top of the walls, the rods attach to a steel “saddle” assembly which transfers the load from the threaded rods into the mass timber wall panels. During shaking, the mass timber panels rock, 在脚跟端提升,在脚趾端压缩墙壁, 虽然总是由后张杆控制和“回到中心”.”
Designed by LEVER Architecture, TallWood项目结构高达112英尺, with four partial façade assemblies. 它在地板上包含了几个大量的木材产品, walls, columns and beams, including cross-laminated timber (CLT), glue-laminated timber, 层压单板木材(LVL)或钉/销钉层压木板, depending on the level.
“This test series demonstrated how a tall mass timber seismic system is can withstand multiple, very high seismic events,WoodWorks高级技术总监Scott Breneman说, PhD, PE, SE. “Coming into these tests, years of component and system tests and thousands upon thousands of computerized earthquake simulations gave the research team the confidence that the tests would pass—but seeing the building pass the actual tests on the NHERI 3-D shake table was a once-in-a-lifetime experience for me. I congratulate Shiling Pei and the extended research and industry team for this achievement.“
“Seeing the building pass the actual tests on the NEHRI 3-D shake table was a once-in-a-lifetime experience for me. I congratulate Shiling Pei and the extended research and industry team for this achievement.’’
- Scott Breneman,博士,PE, SE, WoodWorks高级技术总监
这种规模的研究项目的动机是什么?
The NHERI Tallwood Project could impact forthcoming building codes for residential and commercial structures, 导致更广泛地采用大量木材作为可持续的, strong, 以及多用途的建筑材料——尤其是在容易发生地震的地区. It could also validate mass timber and other innovative technologies as vehicles to help make buildings safer and more resistant to earthquake activity.
美国有11个高大的木材项目已经建成或正在建设中, 几乎所有的都有一个非木材的横向系统, 以钢和混凝土为核心的混合设计解决方案. The NHERI TallWood Project and associated testing can validate an all-timber solution for lateral systems—giving designers, developers, and owners another way to expand their use of mass timber to their project’s advantage. Hybrid systems, 从已完成的高大木材项目中可以看出, 被证明是有效的,并且在许多情况下仍然是一个很好的选择. However, utilizing an all-timber system would maximize the benefits of mass timber on a project—such as lower carbon impact, less coordination between materials, fewer trades on site, and a shorter construction time. An all-timber system like the one being tested would also offer increased resilience with better performance capabilities than structures designed to current code minimums.
At the conclusion of the project, shared Pei, researchers will provide design and construction guidelines for the rocking-wall system, 目标是让它在建筑规范中得到认可. Jonathan Heppner是LEVER测试框架的负责人, shared 甚至在摇墙系统被纳入设计指南之前, 这项研究“将有助于许可证的审批程序.”
请查阅即将公布的建筑测试的全部结果. Already available is the article 后张大质量木结构摇墙抗震设计规程, co-authored by Pei and five others, 去年发表在ASCE结构工程杂志上的文章.
抗震设计的细节:木工皇冠99hg现金网和资源
Following the initial day of testing, WoodWorks hosted an invite-only event at the testing site. 这个节目涵盖了关于这个主题的广泛信息, including a comprehensive overview of current seismic design options within the International Building Code (IBC), implementation of the new CLT shear wall system and structural CLT diaphragms permitted in the 2021 SDPWS, 大块木材岩壁体系的机理, 并具有独特的10层木结构设计属性.
当天的重头戏是振动台测试本身, which offered attendees a rare opportunity to witness the behavior of mass timber structures during seismic events, and to visualize the application of seismic design principles discussed during the workshop.
The course, titled 大体积木材抗震设计及10层NHERI振动台试验研究 是经过认证的,现在可以在Wood Institute的网站上找到吗.