Performance-based design of bridge retrofitting with novel techniques considering life-cycle analysis

加拿大的桥梁库存中有很大一部分已经超过或接近其使用寿命。这类桥梁倒塌的风险很高，特别是在容易发生极端自然事件的地区，极端自然事件越来越频繁，这在很大程度上是由于气候变化的影响。放弃桥梁（全部或部分关闭并限制通行）将严重影响一个地区的运营。用新结构取代有缺陷的桥梁需要大量投资，也会产生大量的碳排放。因此，改造将是降低风险的更安全的方法。有限的财政资源加上加拿大有缺陷的桥梁不断急剧增加，需要采取大胆的行动，而这些行动只能通过系统的、精心设计的和可执行的研究来实现。拟议的学术与产业合作将通过两个途径解决上述挑战。第一个重点是开发一个系统的程序，该程序使用基于性能的原则来识别和优先考虑需要进行抗震改造评估的桥梁。第二部分侧重于引入创新的具有成本效益的桥梁改造和维修措施，以及通过整合生命周期和生命周期成本分析制定基于性能的设计指南。该项目的第一阶段将处理所有公共桥梁的库存。基于数据库中的数据，将使用基于性能的评估对桥梁状况进行详细评估。在下一阶段，创新桥梁改造/修复措施的前景将通过实验程序和广泛的数值模拟相结合的方式进行评估。将制定综合生命周期成本和基于性能的设计指南，以确保所提出的新措施在实践中可实施。研究小组会与设计守则委员会紧密合作，制订适当的架构，把建议的设计建议和指引纳入设计守则。

A large portion of the bridge inventory in Canada has either passed or is approaching its end of service life. Such bridges are at high risk of collapse especially in regions prone to extreme natural events, which are becoming more frequent in large part due to the influence of climate change. Abandoning the bridge (total or partial closure with restricted access) will significantly affect the operation of a region. Replacing deficient bridges with new structures would require substantial investment and also impose significant carbon emission. Hence, retrofitting would be the safer method of mitigating risks. The limited financial resources coupled with the continuous drastic increase of deficient bridges in Canada calls for bold actions which can only be achieved through systematic, well-designed, and implementable research. The proposed academic-industrial collaboration addresses the above challenges through two tracks. The first one focuses on developing a systematic procedure that uses performance-based principles to identify and prioritize bridges that need to be evaluated for seismic retrofitting. The second track focuses on introducing innovative cost-effective bridge retrofit and repair measures and the development of performance-based design guidelines by integrating lifecycle and lifecycle cost analysis. The first phase of this project will deal with the inventory of all publicly owned bridges. Based on the data in the database, detailed evaluations of the bridge conditions will be performed using performance-based assessment. In the next phase, the prospect of innovative bridge retrofitting/repairing measures will be evaluated by a combination of experimental programs and extensive numerical simulations. Integrated lifecycle cost and performance-based design guidelines will be developed to ensure that the proposed novel measures are implementable in practice. The research team will work closely with the design code committee to formulate the appropriate framework with which the proposed design recommendations and guidelines can be incorporated into the design codes.