Incremental Engineered Improvements for Enhanced Seismic Performance in Steel Framed Structures

在加拿大，虽然西海岸的地震风险最大，但主要城市中心及其周围的许多其他地区（例如蒙特利尔、渥太华、魁北克）的地震风险较小，但具有破坏性。必须确保建筑环境能够以高效和具有成本效益的方式抵御所有级别的地震灾害。 现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倒塌极限状态下进行校准以获得良好性能。它们不能保证在其他不太严重但频繁的地面震动水平下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。 拟议的研究旨在开发新类型的支撑元件，这些元件本身经过优化以满足多个性能目标。在这方面，具有不同机械行为特性的多种钢材料（即常规碳、高强度和奥氏体304型不锈钢）用于屈曲约束支撑元件中，以在受到不同水平的地震力时相互补充，同时能够有效控制部件的行为和整体结构响应。设计了全面的测试和分析程序。通过比较新型支撑类型与传统设计技术的性能，进行了增量改进。因此，重要的设计规则，以提供增强的性能在所有极限状态，并提高可靠性。 研究成果对新建和改造有缺陷的框架结构具有一定的参考价值。这项研究的预期成果是显着的，在提供一个改进的技术和高素质的人员谁将领导其在实践中实施的培训。

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.