RAPID: Collection of Data on the Performance of Wood Diaphragms in Buildings during the February 2011 Christchurch, New Zealand Earthquake

这项快速反应研究（Rapid）奖将收集数据，记录2011年2月新西兰基督城地震期间无加固砌体（URM）建筑的性能。具体而言，该合同将记录原始建造和改造的地板和屋顶隔板的能力，以有效地将载荷分配到所有墙壁和其他抗横向载荷元件。从1880年到1970年，新西兰URM建筑通常使用木材托梁、椽子和桁架，与同一时期的美国建筑非常相似。该项目将在定性和定量两方面对地震性能进行分类。在定性层面上，项目将确定urm和有效的缓解技术中典型的弱或差的细节。在数量方面，该项目将制订准则，说明将用于加强美国项目的改造措施的类型和细节。这些指导方针将与美国砌体行业和从业人员密切合作制定，以确保这项研究的结果将迅速转移到美国的实践中。在美国大部分地区，包括东海岸和中西部的大部分地区，建筑存量由URM建筑组成。众所周知，这种类型的建筑在地震荷载下非常容易倒塌；因此，需要有效和经济的改造技术，以减轻损害，确保人身安全。克赖斯特彻奇地震事件提供了独特而卓越的数据，以校准当前美国对这些系统的地震评估和改造实践，包括未使结构达到现行规范要求的100%强度的改造。后一种数据对于抗震改造不是作为一个单一项目进行的情况很重要，而是作为一系列较小的项目，在几年的时间里对现有的URM建筑进行其他改进。提出这种分阶段的方法是为了在较长的时间内分摊成本，使改造更加可行。新西兰的经验将阐明需要首先解决哪些漏洞以及应该使用哪些技术。

This Rapid Response Research (RAPID) award will collect data to document the performance of unreinforced masonry (URM) construction during the February 2011 Christchurch, New Zealand earthquake. Specifically, this award will document the ability of originally constructed and retrofitted floor and roof diaphragms to efficiently distribute loads to all walls and other lateral-load resisting elements. NZ URM construction from 1880 to about 1970 typically used timber joists, rafters, and trusses, very similar to U.S. construction from the same era. The project will catalog seismic performance at both the qualitative and quantitative levels. At the qualitative level, the project will identify weak or poor detailing typical in URMs and effective mitigating technologies. At the quantitative level, the project will develop guidelines for the type and detailing of retrofit measures to be used in strengthening projects in the United States. These guidelines will be developed in close collaboration with the U.S. masonry industry and practitioners to ensure that results from this research will be transferred quickly to American practice.Building stock in large parts of the United States, including most of the east coast and the Midwest, consists of URM construction. This type of building is known to be very susceptible to collapse under earthquake loading; therefore, effective and economical retrofit techniques are needed to mitigate damage and ensure human safety. The Christchurch event provides unique and exceptional data to calibrate current U.S. practices for seismic evaluation and retrofit of these systems, including retrofits that did not bring the structures to 100% of the strength required by current codes. This latter data is important for the case where seismic retrofits will not be carried as a single project, but rather as a series of smaller projects spread over a number of years as other improvements are made to existing URM buildings. This staged approach has been proposed to spread the cost over a longer period and make the retrofits more feasible. The NZ experience will clarify which vulnerabilities need to be addressed first and which techniques should be used.