RAPID/Collaborative Research: The Effects of the 2017 Central Mexico Earthquake on Reinforced Concrete Buildings

这笔快速反应研究补助金(RAPID)将支持来自美国五所大学的研究人员合作团队收集数据，以记录2017年9月19日墨西哥普埃布拉-莫雷洛斯地震期间钢筋混凝土建筑的性能。这次地震的地面震动对震中地区以及墨西哥城(距离震中约120公里)的建筑物造成了广泛的破坏。在墨西哥城，大约40座建筑倒塌，1000多座建筑被确定为中度到严重的结构破坏。2017年的地震影响了一个已经受到1985年强烈地震影响的地区，它提供了一个机会，让我们了解1985年地震后钢筋混凝土建筑维修和翻新的有效性，也提供了一个机会，研究现代和较老的、未修复的钢筋混凝土建筑在强地面运动中的表现。大多数倒塌的建筑是在1985年之前建造的，当时建筑规范还没有进行重大的抗震修订。也有一些较新的和翻新的建筑也遭到破坏。墨西哥城的土壤条件从坚硬的岩石到非常软的土壤，产生了一套影响建筑物的不同的地面条件，这不仅有助于了解墨西哥的抗震建筑性能，也有助于了解美国的抗震建筑性能。由于美国和墨西哥在钢筋混凝土建筑建设方面有相似之处，从这次地震中收集的数据将有助于两国更好的建筑设计和性能评估方法、数值模拟方法和地震烈度指数，并有助于培育更安全的建筑和更具抗震能力的社区。收集的数据将被存档，并在美国国家科学基金会支持的自然灾害工程研究基础设施、数据仓库和侦察集成门户(http://wwww.DesignSafe-ci.org).)中公开提供研究生将参与数据收集，并获得宝贵的震后实地经验。项目组将通过网络研讨会传播其数据收集和研究成果。这一快速项目的目标是收集有关钢筋混凝土建筑损坏的易腐烂数据，这些数据可用于了解和改善美国建筑物的抗震性能和社区的恢复能力。墨西哥的数据收集将与墨西哥的研究人员和工程师合作进行，包括以下活动：(1)调查记录站附近建造的建筑物，重点是翻新建筑物、1985年地震中幸存下来的建筑物和现代建筑物，(2)记录非延性钢筋混凝土建筑物的破坏情况，以校准美国用于识别脆弱建筑物的现有方法，(3)绘制损害图，以测试通常假定的与地震强度指数的相关性，如峰值地面加速度、最大地面速度、最大地面位移以及加速度、速度和位移的峰值或离散频谱值，(4)记录仪表化和基础隔震建筑物的性能，(5)在经过翻新和未进行翻新的损坏和未损坏的钢筋混凝土建筑物上安装加速度计，以记录环境振动和获得建筑物的动力特性，(6)通过观察附近获得的地面运动记录来评估钢筋混凝土建筑物的数值模型，并将数值估计值与观测性能进行比较，以及(7)研究建筑物性能与土壤条件之间的关系。

This Grant for Rapid Response Research (RAPID) will support a collaborative team of researchers from five U.S. universities to collect data to document the performance of reinforced concrete buildings during the Puebla-Morelos, Mexico earthquake of September 19, 2017. The ground shaking from this earthquake caused widespread damage to buildings in the epicentral region, as well as in Mexico City (approximately 120 kilometers from the epicenter). In Mexico City, approximately 40 buildings collapsed, and over one thousand structures have been identified with moderate to major structural damage. The 2017 earthquake, having impacted an area that had already been shaken by a strong earthquake in 1985, provides an opportunity to learn about the effectiveness of reinforced concrete building repairs and retrofits made after the 1985 earthquake, as well as an opportunity to study how modern and older, unrepaired reinforced concrete buildings performed during strong ground motion. The majority of collapsed buildings were constructed prior to 1985 before there were major seismic revisions to building codes. There were also a few cases of newer and retrofitted buildings that also sustained damage. Mexico City has soil conditions ranging from stiff rock to very soft soil, producing a diverse set of ground conditions affecting buildings that can facilitate understanding of seismic building performance not only in Mexico, but also in the United States. Because the United States and Mexico have similarities in reinforced concrete building construction, the collected data from this earthquake will contribute to better building design and performance assessment methods, numerical simulation methods, and earthquake intensity indices in both countries, and help foster safer buildings and more earthquake-resilient communities. The collected data will be archived and made publicly available in the NSF-supported Natural Hazards Engineering Research Infrastructure, Data Depot and Reconnaissance Integration Portal (http://wwww.DesignSafe-ci.org). Graduate students will participate in the data collection and gain valuable post-earthquake field experience. The project team will disseminate its data collection and research findings through a webinar. The goal of this RAPID project is to collect perishable data on reinforced concrete building damage that can be used towards understanding and improving seismic performance of buildings and the resilience of communities in the United States. The data collection in Mexico will be conducted in collaboration with researchers and engineers in Mexico and include the following activities: (1) survey buildings built near recording stations with emphasis on retrofitted buildings, buildings that survived the 1985 earthquake, and modern buildings, (2) document damage to non-ductile reinforced concrete buildings for calibration of existing methodologies used to identify vulnerable buildings in the United States, (3) map damage to test commonly assumed correlations with earthquake intensity indices such as peak ground acceleration, peak ground velocity, peak ground displacement, and peak or discrete spectral values of acceleration, velocity and displacement, (4) document the performance of instrumented and base-isolated buildings, (5) deploy accelerometers on damaged and undamaged reinforced concrete buildings with and without retrofits to record ambient vibrations and obtain building dynamic properties, (6) evaluate numerical models of reinforced concrete buildings by subjecting them to ground motion records obtained nearby and compare the numerical estimates and observed performance, and (7) study relationships between building performance and soil conditions.