Controlled rocking steel systems: from concept to design

公众普遍认为新建筑是“抗震的”，这意味着它们可以在地震后使用而不需要维修。然而，目前的设计规范只试图确保建筑物在地震后能够安全疏散。因此，符合规范的结构很可能会受到设计级地震的破坏，即使它们的行为与预期完全相同。新西兰克赖斯特彻奇最近就证明了这一点，那里2010-2011年的一系列地震导致中央商务区70%的建筑被拆除。2013年，加拿大保险局委托的一份报告警告称，预计将在西海岸发生的那种地震，将造成750亿美元的损失。这类灾难的极端社会经济代价令人质疑接受损害的设计理念是否明智。然而，这一理念不太可能改变，除非能够在不大幅增加初始建设成本的情况下构建性能更好的系统。这项研究计划将通过开发能够在不造成结构破坏的情况下抵御地震的经济系统，极大地提高已建成基础设施的弹性和可持续性，而基础设施是加拿大经济的核心。 一种特殊的系统显示出以具有竞争力的初始成本改善地震韧性的前景，这是一种受控摇动钢系统。虽然在理解这一制度方面取得了重大进展，但有几个关键问题阻碍了它的广泛实施。在接下来的5年里，这项研究计划将回答阻止受控摇摆钢系统从概念到设计的最紧迫的问题。随着这些问题的回答，加拿大将制定设计指南，在未来5-10年内，这将导致受控摇摆钢系统在加拿大国家建筑规范(NBCC)中被指定为可接受的抗震系统，并在加拿大钢铁标准CSA S16的第27节中做出适当的规定。这项研究计划的长期目标是使损害避免成为加拿大所有结构抗震设计的常规部分，而不是作为特殊结构的特殊设计目标。

The public generally assumes that new buildings are “earthquake-proof,” meaning that they could be used after an earthquake without repair. However, current design codes attempt only to ensure that a building can be safely evacuated after an earthquake. Therefore, code-compliant structures are likely to be damaged by design-level earthquakes, even if they behave exactly as intended. This was recently demonstrated in Christchurch, New Zealand, where a series of earthquakes in 2010-2011 has led to the demolition of 70% of the buildings in the central business district. In 2013, a report commissioned by the Insurance Bureau of Canada warned of $75 billion in losses due to the kind of earthquake that is expected to occur off the west coast. The extreme socio-economic cost of such disasters calls into question the wisdom of a design philosophy that accepts damage. However, this philosophy is unlikely to change unless systems with better performance can be built without greatly increasing the initial construction cost. This research program will greatly improve the resilience and sustainability of built infrastructure, which is at the core of the Canadian economy, by developing economical systems that can withstand earthquakes without structural damage. One particular system that shows promise for improving seismic resilience at a competitive initial cost is a Controlled Rocking Steel System. Although significant progress has been made on understanding this system, several key questions prevent it from being implemented widely. Over the next 5 years, this research program will answer the most pressing questions that prevent Controlled Rocking Steel Systems from moving from concept to design. As these questions are answered, a Canadian design guideline will be developed, and over the next 5-10 years, this is expected to lead to Controlled Rocking Steel Systems being specified as an acceptable seismic force resisting system in the National Building Code of Canada (NBCC), with appropriate provisions in Section 27 of the Canadian Steel Standard CSA S16. The long-term objective of this research program is to make damage avoidance a routine part of seismic design for all structures in Canada, rather than being a special design objective that is reserved for exceptional structures.