Risk-based evaluation and optimization of friction devices for seismic retrofits of non-ductile building structures in Canada

加拿大早期设计的公共建筑(即学校和医院)面临着严重的地震破坏和倒塌风险。安装地震保护装置，如Quaketek Inc.设计和制造的摩擦装置，为降低建筑结构的地震风险提供了一种可行的策略。然而，摩擦装置的实际使用通常依赖于涉及少量地震地面运动的规范方法，这不能解决几个关键挑战，包括(1)地震危险的不确定性；(2)从结构性能到成本效益性能的转换；(3)结构和非结构部件的损坏和损失；(4)随机优化的高计算成本；以及(5)减少地震损失和增加前期成本之间的竞争标准。基于性能的地震工程(PBEE)框架基于这样一个承诺，即地震风险可以通过所有相关不确定性的可量化置信度进行评估，从假设地震发生模型到地震后果(例如，人员伤亡、损失和停机时间)的估计。通过进一步整合统计学和机器学习方面的最新进展，拟议的项目旨在扩展PBEE框架，以评估、设计和优化加拿大东部和西部不同类型公共建筑的摩擦装置。通过高保真有限元模型支持的非线性时程分析、地震生命周期成本效益分析和基于地震风险的优化，确定摩擦装置的最佳布局和设计参数的设计准则将朝着最小化非延性钢框架、混凝土框架和低层木框架以及非延性和延性混凝土剪力墙的地震损失的方向发展。该项目将把目前使用的这种摩擦装置构建为一种有价值且具有成本效益的抗震改造解决方案，可以更好地保护加拿大的公共建筑免受地震危害。

Canada's early-designed public buildings (i.e., schools and hospitals) are at significant risk of seismic damage and collapse. The installation of seismic protective devices, such as friction devices designed and manufactured by Quaketek Inc, offers a viable strategy to mitigate the seismic risk of building structures. However, the practical use of friction devices has commonly relied on prescriptive approaches that engage a small number of earthquake ground motions, which fall short of tackling several critical challenges, including (1) uncertainties in seismic hazard; (2) the conversion from structural behaviour to cost-benefit performance; (3) the damage and loss of both structural and non-structural components; (4) the high computational cost for stochastic optimization; and (5) the competing criteria between reduced seismic loss and increased upfront cost. The performance-based earthquake engineering (PBEE) framework stands on the promise that seismic risk can be assessed with quantifiable confidence of all pertinent uncertainties, ranging from premise earthquake occurrence modelling to the estimates of earthquake consequences (e.g., casualties, loss, and downtime). By further integrating the recent advances in statistical and machine learning, the proposed project aims to extend the PBEE framework to evaluate, design, and optimize the friction devices for different types of public buildings in both east and west Canada. Through nonlinear time history analyses supported by high-fidelity finite element modelling, seismic life-cycle cost-benefit analyses, and seismic risk-based optimization, design guidelines identifying optimal layouts and design parameters of friction devices will be developed towards minimized seismic losses for non-ductile steel frames, concrete frames, and low-rise wood frames, as well as non-ductile and ductile concrete shear walls. This project will structure the current use of this type of friction device as a valuable and cost-effective seismic retrofit solution that can better safeguard Canada's public buildings against earthquake hazards.