Development of Innovative Design Methods for Enhanced Seismic Stability of Steel Framed Building Structures

在加拿大，当工业、商业和住宅建筑设计用于抵抗地震荷载时，经常使用两种结构框架：钢多层支撑框架和钢抗弯框架。多层支撑框架有两个或多个支撑面板堆叠在地面和屋顶之间。抗弯矩框架是由梁和柱组成的刚性框架。对这两种系统的行为进行研究，制定了抗震设计指南，并对钢结构设计标准进行了调整。然而，最近的分析和实验研究观察到一些不希望的失败，没有完全理解。此外，目前的钢结构设计标准中还没有对某些破坏进行适当的处理。对于承受地震荷载的多层支撑框架，最近提出了特殊的设计要求，以改善框架的性能。尽管如此，框架稳定性可能会受到框架柱中引起的平面外弯矩的影响;这必须在设计中反映出来。为了获得更好的稳定性响应，还必须制定能反映地震荷载作用下框架实际性能并降低施工成本的替代设计策略。对于抗弯框架，地震荷载作用下的弯曲屈服和局部屈曲可能导致柱失稳。通过了解组合效应，我们可以开发出反映相互作用的合适的抗震设计标准。我的长期研究计划旨在开发新的系统和设计方法，以最小的建筑成本提高加拿大钢结构的地震响应和安全性。本研究计划的总体目标是为多层钢支撑框架和抗弯框架制定抗震设计指南，以防止柱失稳。本研究计划的具体目标是：1）开发多层支撑框架柱在面内和面外地震耦合作用下的设计方法2）开发特殊的分析和设计方法，通过选择支撑构件来控制多层支撑框架的面内地震性能3）建立地震荷载作用下深、细长抗弯框架柱主要侧向稳定极限状态的强度和稳定性要求。我们针对每个目标的方法包括理论建模、实验和结构分析知识。我们将为下一个加拿大钢结构设计标准制定抗震设计建议。此外，我们将为从业者提供改进的分析和设计工具，可以应用于日常实践。

When industrial, commercial and residential buildings are designed in Canada to resist seismic load, two structural frames are frequently used: steel multi-tiered braced frames and steel moment-resisting frames. Multi-tiered braced frames have two or more bracing panels stacked between the ground and roof levels. Moment-resisting frames are built from beams and columns that are rigidly framed together. Research on behaviour of both systems led to seismic design guidelines and adaptations in steel design standards. However, recent analytical and experimental studies observed several undesirable failures that are not fully understood. Further, some failures are not properly addressed in current steel design standards.For multi-tiered braced frames under earthquake loads induced in the plane of the frame, special design requirements were recently proposed to improve frame behaviour. Still, frame stability may be compromised by concomitant out-of-plane bending moments induced in the frame columns; this must be reflected in design. Alternative design strategies that reflect actual behaviour of the frame under earthquake loads and reduce construction costs must also be developed for better stability response.For moment-resisting frames under earthquake loads, flexural yielding and local buckling may cause instability of columns. By understanding combined effects, we can develop suitable earthquake-resistant design criteria that reflect interactions.My long-term research program aims to develop novel systems and design methods that improve seismic response and safety of steel structures in Canada, with minimized construction costs. This research program's general objective is to develop seismic design guidelines for steel multi-tiered braced frames and moment-resisting frames in order to prevent column instability.The specific objectives of this research program are to:1) develop design methods for columns of multi-tiered braced frames under coupled in-plane and out-of-plane seismic demands2) develop special analysis and design methods to control in-plane seismic behaviour of multi-tiered braced frames by selection of bracing members3) establish strength and stability requirements for dominant lateral stability limit states of deep, slender moment-resisting frame columns under seismic load effects.Our methods for each objective include theoretical modeling, experiments and structural analysis knowledge. We will develop seismic design recommendations for the next Canadian steel design standard. Furthermore, we will provide practitioners with improved analysis and design tools that can be applied in day-to-day practice.