NEESR Planning: The Role of Gravity Framing in the Seismic Performance of Steel Buildings

这项研究的总体目标是更好地了解重力框架在钢结构建筑抗震性能中的作用，以及量化这种作用的数据、模型和工具。在钢结构建筑的设计中，通常不认为重力式框架对抗震侧向荷载有贡献。然而，在现实中，重力框架可以显著提高抗侧向荷载，并显著提高抗震性能。目前，对这一角色还缺乏充分的认识。此外，用来量化重力框架系统对抗震性能的影响所需的数据和模型也非常缺乏。这项研究将建立一个用于重力式框架的典型简支梁柱剪力连接试验的数据库，通过一系列在重力和循环侧向荷载作用下的简单剪力连接的大型试验产生新的试验数据，建立不同复杂程度和细节水平的连接模型，并开发用于重力式框架的初步系统级模型。这项研究还将提供进行后续研究项目所需的信息，以检查钢结构建筑中重力和横向组合系统的系统级行为。这项研究可能对美国新建和现有钢结构建筑的抗震设计和评估程序产生重大实际影响，以提高安全性和经济性为更广泛的目标。最大的影响可能是对现有钢结构建筑物的地震安全性的评估，在一些情况下，将重力系统纳入评估可能会排除需要昂贵的抗震改造措施。这项研究还将对重力系统如何影响新钢结构建筑的抗震性能提供更深入的见解，并将为新建筑中重力系统的设计和细节设计提供最佳实践的信息。这项研究对美国低地震区新建钢结构建筑的抗震设计也有潜在的影响，在这些地区，重力框架对横向抗震的贡献可能是巨大的。该项目的数据将被存档，并通过NEES数据库向公众提供。该奖项是国家减少地震灾害计划(NEHRP)的一部分。

The overall goal of this research is to develop a better understanding of the role of gravity framing in the seismic performance of steel buildings, along with the data, models and tools to quantify this role. In design of steel buildings, the gravity framing is not usually considered as contributing to the resistance of seismic lateral load. In reality, however, the gravity framing can contribute substantial lateral load resistance and significantly improve seismic performance. At present, a full understanding of this role is still lacking. Moreover, the data and models needed to quantify the effect of the gravity framing system on seismic performance are also largely lacking. This study will develop a database of previous experiments on typical simple beam-to-column shear connections used in gravity framing, generate new experimental data from a series of large-scale experiments on simple shear connections under combined gravity and cyclic lateral load, develop connection models at various levels of complexity and detail, and develop preliminary system level models for gravity framing. This research will also provide information needed to conduct a follow-on research project examining system level behavior of combined gravity and lateral systems in steel buildings.This research has the potential for significant practical impact on seismic design and evaluation procedures for new and existing steel buildings in the United States, with a broader goal of improved safety and economy. The largest impact is likely to be on the evaluation of seismic safety of existing steel buildings, where inclusion of the gravity system in the evaluation may, in a number of cases, preclude the need for costly seismic retrofit measures. This research will also provide greater insights into how the gravity system affects seismic performance of new steel buildings, and will provide information on best practices for the design and detailing of the gravity system in new buildings. This research also has potential impact on the seismic design of new steel buildings in lower seismic zones in the United States, where the contribution of the gravity framing to lateral seismic resistance may be substantial. Data from this project will be archived and made available to the public through the NEES data repository. This award is part of the National Earthquake Hazards Reduction Program (NEHRP).