Incremental Engineered Improvements for Enhanced Seismic Performance in Steel Framed Structures

在加拿大，虽然最大的地震风险是在西海岸，但在主要城市中心及其周围的许多其他地区（例如montracimal，渥太华，quacimbec）容易发生较小但具有破坏性的风险。至关重要的是，要确保建筑环境能够以有效和具有成本效益的方式抵御各级地震灾害。****当代建筑规范中可用的抗震系统通常在非常高强度的地面震动水平下，在生命安全或防止倒塌的极限状态下具有良好的性能。它们不能保证在其他不那么严重但频繁的地面震动中具有良好的结构性能。换句话说，目前的设计不能在所有极限状态下提供可靠和足够的结构性能。****提出的研究旨在开发新型的支撑元件，这些元件本质上是优化的，以满足多种性能目标。在这方面，具有不同力学行为性能的多种钢材（即普通碳，高强度和304型奥氏体不锈钢）被用于屈曲约束支撑元件，以便在受到不同程度的地震力时相互补充，同时有效控制组件的行为和整体结构响应。设计了全面的测试和分析方案。通过与传统设计技术的性能比较，对新型支撑进行了改进。因此建立了重要的设计规则，以在所有极限状态下提供增强的性能并提高可靠性。****研究结果将有利于新建和改造现有的缺陷框架结构。这项研究的预期结果是显著的，既提供了改进的技术，又培训了在实践中领导其实施的高素质人员。**********************************

In Canada, while the greatest seismic risk is on the west coast, many other regions in and around major urban centers (e.g. Montréal, Ottawa, Québec) are prone to lesser but damaging risks. It is essential to ensure that the built environment is resilient to all levels of seismic hazards in an efficient and cost-effective manner. ****Earthquake-resistant systems available in contemporary building codes are calibrated for good performance at the life safety or collapse prevention limit states often under very high intensity ground shaking levels. They do not guarantee good structural performance at other less severe but frequent levels of ground shaking. In other words, the current designs do not offer reliable and adequate structural performance across all limit states. ****The proposed research aims at developing new types of brace elements that are inherently optimised to meet multiple performance objectives. In this respect, multiple steel materials with different mechanical behaviour properties (i.e. regular carbon, high strength and austenitic Type 304 stainless steels) are employed in the buckling-restrained brace element to complement each other when subjected to different levels of earthquake forces, while enabling effective control of the component`s behaviour and the overall structural response. Comprehensive testing and analytical programs are designed. Incremental improvements are made by comparing performance of the novel brace types to the traditional design technique. Important design rules are consequently established to deliver enhanced performance at all limit states and to improve reliability. ****The research findings will be beneficial to both new construction and retrofitting of existing deficient framed structures. The anticipated outcome of this research is significant, in terms of both delivering an improved technology and the training of highly qualified personnel who would lead its implementation in practice.**********************************