Towards a Balanced Seismic Design Procedure for Strength and Ductility Requirement

该项目的主要目标 是制定一个程序， 平衡结构的实际 强度和所需的延展性 钢架要求 设计 钢框架是 通常用于低到中等- 在所有地震中上升的建筑物 区界限 不像钢筋混凝土 钢框架构件尺寸 力矩框架通常 受漂移限制;因此 结构实际强度可以 要比这高得多 抗震规范要求。 不幸的是，这种独特的功能 钢结构设计不被认可 严格的抗震规范 规定的延性要求 在这些代码中， 保守. 此外，由于 严格的延性 制定了要求 主要用于高地震带， 其应用于中、低 地震带受到质疑。 所提出的设计过程 明确认为， 结构强度过大， 从漂移限制; 所需的延展性由以下因素平衡： 这种超强的力量。 除了 两种延性等级（特殊和 普通力矩框架）， 在抗震条款中被采用， 第三类（中间力矩 框架）将在 项目 因此，经济设计 它提供了一个更一致的 所有地震的安全水平 区域可以实现。 一个有效的计算机程序将 开发用于计算结构 力量过大 几个瞬间 框架位于不同的地震 区域将由 常规和建议设计 方法. 可行性研究将 进行的工作和节省的费用 由于拟议的设计 方法将被注意到。 安全水平 钢框架设计， 还将比较这两种方法 通过执行非线性动力学 分析.

The main objective of this project is to develop a procedure to balance the structure's actual strength and the required ductility requirements for steel frame design. Steel moment frames are popularly used for low-to medium- rise buildings in all seismic zones. Unlike reinforced concrete frames, member sizes of steel moment frames are quite often governed by drift limits; therefore the structure's actual strength may be significantly higher than that required by seismic codes. Unfortunately, this unique feature of steel design is not recognized by seismic codes, and stringent ductility requirements as specified in these codes may be too conservative. Furthermore, since the stringent ductility requirements are developed primarily for high seismic zones, its application to moderate or low seismic zones has been questioned. The proposed design procedure considers explicitly the beneficial structural overstrength resulting from drift limitations; the required ductility is balanced by this overstrength. In addition to two ductility classes (Special and Ordinary Moment Frames) which have been adopted in seismic provisions, a third class (Intermediate Moment Frame) will be developed in the project. Thus an economic design which provides a more consistent safely level for all seismic regions can be achieved. An efficient computer program will be developed to compute structural overstrength. Several moment frames located in different seismic zones will be designed by both the conventional and proposed design methods. Feasibility study will be conducted and cost savings resulting from the proposed design method will be noted. Safety level of steel moment frames designed by both methods will also be compared by performing nonlinear dynamic analysis.