Improving Seismic Performance of Asymmetric Buildings: Plan-wise Distribution of Supplemental Damping

对称建筑(质量和/或刚度、和/或楼层强度分布不规则的建筑)特别容易受到地震的影响。该研究项目的主要目标是制定必要的背景和指导方针，以提高不对称建筑的抗震性能。第一阶段的研究将集中在具有非延性结构构件(梁、柱、墙等)的建筑。这可以被允许经历没有损害或非常有限的损害，即必须在或接近线性弹性行为范围内响应的建筑物。这是一堂很重要的课。加州等高地震区的许多旧建筑(设计于现代地震规范制定之前)，以及美国中部和东部等中低地震区的大多数较新建筑都属于这一类。第二阶段将重点关注具有延性结构构件的建筑，即可以允许在非弹性行为范围内做出反应的建筑，但构件需求(位移、延性或能量)必须侧重于使用带有补充减震装置的不对称建筑的大型模型进行概念验证实验。目前，三个阶段中的前两个阶段正在提供资金；最后阶段的资金将在前两个阶段成功完成后申请。所进行的调查将使人们能够制定改进的方法，对不对称建筑进行抗震保护，这类建筑特别容易发生地震，但并不总是能够避免。拟议研究将产生的指导方针和简化的设计程序也将导致基于性能的地震标准的改进，如FEMA-273。

A symmetric building (buildings with irregular distribution of mass, and/or stiffness, and/or strengths in their floor plans) is especially vulnerable to earthquakes. The primary objective of the research project is to develop the background and guidelines necessary to improve seismic performance of asymmetric buildings by using supplemental damping.The first phase of research will focus on buildings with non-ductile structural elements (beams, columns, walls etc.) that can be allowed to experience no damage or very limited damage, i.e., buildings that must respond in or close to the linearly elastic range of behavior. This is an important class. Many older buildings in high seismic regions like California (designed prior to the development of modern seismic codes) as well as most newer buildings in low to moderate seismic regions like central and eastern U.S. of all in this category. The second phase will focus on buildings with ductile structural elements, i.e., buildings that may be permitted to respond in the inelastic range of behavior but the element demands (displacement, ductility, or energy) must focus on proof-of-concept experiments using large scale models of asymmetric buildings with supplemental damping devices. At present, funding is being provided for first two of the three phases; funding for the final phase would be requested after successful completion of the first two phases.The investigation undertaken will enable the development of improved methods for seismic protection of asymmetric buildings, a class that is especially vulnerable to earthquakes but not always possible to avoid. The guidelines and simplified design procedures that will result from the proposed research would also lead to improvements in performance-based seismic standards such as FEMA-273.