Structural Control with Seismic Base Isolation Technology

由于地震灾害，加拿大的城市面临着巨大的风险。除了可能对建筑物造成灾难性破坏和造成生命损失外，地震还在重建和安置流离失所者方面提出了严重的长期挑战。传统的抗震结构设计方法侧重于生命安全，预测和接受结构将发生的破坏。最先进的抗震技术，如基础隔震，旨在减少对结构的抗震需求。这个概念需要安装专门的设备，可以适应大的偏转而不损坏。地震引起的变形集中在这一柔性层，而不是传递给结构，有效地保护了居住者不受伤害，结构和内容物不受破坏。最近，《加拿大国家建筑规范》中列入了有关基础隔离技术的规定。基极隔离装置的设计已向复杂自适应装置发展。这些装置可以根据地震的震级调整结构的反应。尽管自适应装置的潜在好处是有希望的，但这种装置在极端负载水平下的性能还没有得到很好的理解。这可能会导致不可预见的后果或错失提高性能的机会。此外，基础隔离系统的设计必须完全包含并考虑所有负载源。例如，由于基础隔离装置固有的灵活性，在低空风下，结构可能容易受到微小运动的影响，从而干扰诸如磁共振成像（MRI）机器等振动敏感设备的性能。此外，在极端地震事件中控制结构最大运动的最佳方法尚未确定。利用基础隔震系统不仅可以提高结构的抗震性能，而且在受到风、铁路和交通等其他外部振动源的影响时也具有优异的振动性能。不考虑备选振动源可能会降低结构的效用，并直接影响日常活动。对极端地震事件的结构设计不充分可能是灾难性的，并涉及生命安全问题。最近将基础隔离纳入加拿大国家建筑规范，使这一领域的研究对加拿大和加拿大工业具有相关性和及时性。本研究的目的是通过在加拿大和全世界推广基础隔离技术来降低地震风险。它还可以指导设计人员确保基础隔振系统不会无意中对结构的振动性能产生负面影响，而是增强它。

Canadian cities are at significant risk due to seismic hazards. In addition to the potential for catastrophic damage to structures and loss of life, earthquakes present serious long-term challenges in the form of rebuilding and accommodating displaced people. Conventional approaches to designing structures for seismic loads focus on life safety, anticipating and accepting that damage to the structure will occur. State-of-the-art seismic protection technologies, such as base isolation, aim to reduce the seismic demand on the structure. The concept requires the installation of specialized devices that can accommodate large deflections without damage. The deformation due to the earthquake is concentrated at this flexible layer rather than being transmitted to the structure, which effectively protects the occupants from harm and the structure and the contents from damage. Provisions for base isolation technology have recently been included in the National Building Code of Canada. The design of base isolation devices has progressed towards complex adaptive devices. These devices allow the response of the structure to be tailored to the magnitude of the earthquake. Although the potential benefits of adaptive devices are promising, the performance of such devices at extreme load levels is not well understood. This may lead to unforeseen consequences or missed opportunities for improved performance. Furthermore, the design of a base isolation system must fully encompass and consider all load sources. For example, due to the inherent flexibility in base isolation devices, under low-level winds, the structure may be susceptible to small movement that interferes with the performance of vibration-sensitive equipment such as Magnetic Resonance Imaging (MRI) machines. Additionally, the optimal approach to control the maximum motion of the structure during extreme earthquake events has yet to be determined. There exists significant potential to utilize a base isolation system to not only improve the seismic performance of a structure, but to also have excellent vibration performance when subjected to other external vibration sources such as wind, rail and traffic. Failure to account for alternative vibration sources may reduce the utility of the structure and directly impact day-to-day activities. Failure to adequately design the structure for extreme earthquake events could be catastrophic and a life safety concern. The recent inclusion of base isolation in the National Building Code of Canada makes research in in this area relevant and timely for Canada and Canadian industry. The objective of this research is to mitigate seismic risk by promoting base isolation technology in Canada and throughout the world. It is also to guide designers to ensure that a base isolation system does not inadvertently negatively impact the vibration performance of a structure but enhances it.