RAPID: Assessing the Performance of Elevated Wood Buildings, including Manufactured Housing, in Florida during 2018 Hurricane Michael

RAPID：评估 2018 年迈克尔飓风期间佛罗里达州高架木建筑（包括活动房屋）的性能

• 批准号: 1903486
• 负责人: Elaina Sutley
• 金额: $ 4.46万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-12-01 至 2020-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903486&HistoricalAwards=false
• 关键词: RAPID; Assessing; Performance; Elevated; Wood

This Grant for Rapid Response Research (RAPID) will investigate the wind performance of elevated site-built and manufactured housing during Hurricane Michael, which made landfall in Florida on October 10, 2018, just a few miles per hour (mph) below a Category 5 hurricane. This hurricane was the strongest to hit the continental United States since Hurricane Andrew in 1992. The observed impact of Hurricane Michael presents a unique and important opportunity to investigate the wind performance of elevated site-built and manufactured housing, given that recorded wind speeds reached and exceeded design winds at the coast and further inland. Florida has one of the largest inventories in the United States of manufactured housing, the most vulnerable residential structure to hurricanes, which also often houses the most socially vulnerable households. While damage to manufactured housing has been widely noticed following major hurricane events, this type of structure has received minimal research attention. Manufactured housing is a subset of elevated housing, where elevated site-built homes are also very common in the areas impacted by Hurricane Michael. The influence that the elevation height, stilt distribution, and foundation type have on wind loading and damage experienced by elevated site-built and manufactured housing structures is presently unknown. This project will investigate these fundamental knowledge gaps through ephemeral data collection of the performance of elevated housing following Hurricane Michael. Damage to housing is often responsible for half of the disaster losses following major hurricane events notwithstanding the widespread disruption it causes through household dislocation. Findings from this study will be shared with national and state-level codes and standards committees to improve the resilience of common, but understudied, residential buildings, in order to promote continuity in national welfare and prosperity following a hurricane event. Data collected through this grant will be shared on the NHERI Data Depot and Reconnaissance Portal (https://www.DesignSafe-ci.org) for broad use by the engineering community.The Hurricane Michael wind field had a wide range of inland wind speeds, and thus presents the opportunity for on-site damage investigation of different types of residential building structures, including elevated site-built and manufactured homes. Current codes and standards do not account for the air flow that occurs underneath elevated residential buildings. Preliminary research has shown that different elevations could amplify the wind pressures measured on the wall and roof surfaces, suggesting unconservatism in current code-based design approaches. This RAPID award will assess damage to a range of elevated and non-elevated homes, and make comparisons based on elevation height, stilt distribution, and foundation type in areas that experienced design-level and higher wind speeds during Hurricane Michael. Furthermore, manufactured homes in the Hurricane Michael impacted areas are designed for either Zone II (100 mph) or Zone III (110 mph) peak wind speeds, as well as for 75 mph sustained wind for transportation on highway/interstate purposes. Most wind loads used in design currently consider three-second gust wind speed, which is an instant wind load that assumes structural component and material behaviors stay in the linear range during an extreme wind event. Examining damage to manufactured housing at the sites where wind speeds were sustained at 75 mph or less will advance missing knowledge on whether failures are initiated by fatigue, caused by sustained wind loads, and progress into catastrophic failure of the unit. This gained knowledge will direct future research foci for manufactured housing studies to have better damage mitigation plans for both retrofit (old) and design (new) of manufactured homes. The reconnaissance team will enter areas in Florida affected by Hurricane Michael and collect on-site data, including images of damage and building information, for analyses and advancement of fundamental knowledge on elevated site-built and manufacturing housing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项快速反应研究（RAPID）拨款将调查飓风迈克尔期间高架场地建造和制造的房屋的风性能，该飓风于2018年10月10日在佛罗里达登陆，仅低于5级飓风每小时几英里。这场飓风是自1992年飓风安德鲁以来袭击美国大陆的最强飓风。 鉴于海岸和内陆记录的风速达到并超过了设计风速，迈克尔飓风的观察影响为研究高架现场建造和制造的房屋的风力性能提供了一个独特而重要的机会。 佛罗里达拥有美国最大的制造业住房库存之一，这是最容易受到飓风袭击的住宅结构，也往往是社会上最脆弱的家庭。虽然在重大飓风事件后，人们广泛注意到了对人造房屋的破坏，但这种类型的结构却很少受到研究关注。 人造房屋是高架房屋的一个子集，在受飓风迈克尔影响的地区，高架房屋也很常见。目前尚不清楚标高高度、支柱分布和基础类型对高架现场建造和制造的房屋结构所经历的风荷载和损坏的影响。本项目将通过收集飓风迈克尔后高架房屋性能的短暂数据来调查这些基本知识差距。在重大飓风事件之后，尽管住房因家庭流离失所而造成广泛的破坏，但住房损坏往往是造成灾害损失的一半原因。这项研究的结果将与国家和州一级的规范和标准委员会分享，以提高普通但研究不足的住宅建筑的复原力，以促进飓风事件后国家福利和繁荣的连续性。通过这项赠款收集的数据将在NHERI数据仓库和侦察门户网站（https：//www.example.com）上共享，供工程界广泛使用。飓风迈克尔风场的内陆风速范围很广，因此提供了对不同类型的住宅建筑结构进行现场损坏调查的机会，包括高架工地建造和制造的房屋。www.DesignSafe-ci.org目前的规范和标准没有考虑到高层住宅建筑下方发生的空气流动。初步研究表明，不同的标高可以放大在墙壁和屋顶表面测量的风压，这表明当前基于规范的设计方法是不保守的。该RAPID奖项将评估一系列高架和非高架房屋的损坏情况，并根据迈克尔飓风期间经历设计水平和更高风速的地区的海拔高度，高跷分布和基础类型进行比较。此外，迈克尔飓风影响地区的制造房屋设计用于II区（100英里/小时）或III区（110英里/小时）的峰值风速，以及用于高速公路/州际公路运输的75英里/小时持续风速。目前，设计中使用的大多数风荷载都考虑三秒阵风风速，这是一种瞬时风荷载，假定结构构件和材料行为在极端风事件期间保持在线性范围内。在风速维持在75 mph或更低的现场检查制造的外壳的损坏将推进关于故障是否由疲劳引起、由持续的风荷载引起以及进展为机组灾难性故障的知识。这些知识将指导未来的研究重点，为制造房屋的研究，有更好的损害缓解计划改造（旧）和设计（新）的制造房屋。勘察小组将进入受飓风迈克尔影响的佛罗里达地区，收集现场数据，包括损坏图像和建筑信息，用于分析和提高高架现场建造和制造房屋的基础知识。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Performance of Manufactured Housing during Hurricanes Irma and Michael

活动房屋在飓风“艾尔玛”和“迈克尔”期间的性能

• DOI: 10.1061/(asce)cf.1943-5509.0001486
• 发表时间: 2020
• 期刊: Journal of Performance of Constructed Facilities
• 影响因子: 2.5
• 作者: Sutley, Elaina J.;Vazquez, Karen;Kim, Jae H.;Dao, Thang;Johnston, Blythe;Hunt, Josh
• 通讯作者: Hunt, Josh

Observations and analysis of wind pressures on the floor underside of elevated buildings

高架建筑楼板底面风压观测与分析

• DOI: 10.1016/j.engstruct.2020.111101
• 发表时间: 2020
• 期刊: Engineering Structures
• 影响因子: 5.5
• 作者: Kim, Jae H.;Moravej, Mohammadtaghi;Sutley, Elaina J.;Chowdhury, Arindam;Dao, Thang N.
• 通讯作者: Dao, Thang N.