Deformation Hazard Curves for Development of Seismic Risk Maps for Bridges

提出的研究计划的主要目标是开发一种新的方法来评估桥梁的地震易损性。该方法基于变形危险曲线的使用，它代表了不同变形水平（从弹性变形到坍塌）的平均年概率。与目前使用的易损性曲线相比，变形危险曲线具有明显的优势。也就是说，变形危险曲线涵盖了桥梁在其使用寿命期间可能经历的所有响应，并包括桥梁位置地震危险的影响。通过选取单一的全局变形参数对响应进行量化，并通过不同烈度指标的年超过概率来表示桥梁位置的地震危险性。变形参数和强度测量是该方法中的关键参数，并对这些参数的选择进行了专门的研究。****变形危险曲线的发展方法将为桥梁的地震易损性评价提供一种新的可靠方法。作为本提案的一部分，将制定描述该方法使用的逐步过程的指导方针，使学术界的研究人员以及设计办公室的工程分析人员能够广泛使用该方法。该方法将以一般形式制定，并可在世界上任何国家使用。然而，在本提案的背景下，加拿大桥梁地震易损性评估方法的应用具有特别重要的意义。根据提出的方法开发的桥梁变形危险曲线可用于根据桥梁的易损性对桥梁进行排序，从而用于开发桥梁的地震风险图。此外，所提出的方法将非常有利于改进加拿大公路桥梁设计规范的抗震规定。* * * * * *

The main goal of the proposed research program is to develop a new methodology for the seismic vulnerability assessment of bridges. The methodology is based on the use of deformation hazard curves, which represent the mean annual probabilities of exceedance of different deformation levels (from elastic deformations to collapse). The deformation hazard curves have significant advantages compared with the fragility curves that are currently used. Namely, the deformation hazard curves cover all the responses that the bridge might experience during its lifespan, and include the effects of the seismic hazard at the bridge location. The responses are quantified by a selected single global deformation parameter, and the seismic hazard at the bridge location is represented by the annual probability of exceedance of different levels of an intensity measure. The deformation parameter and the intensity measure are key parameters in the methodology, and special investigations are proposed for the selection of these parameters.****The methodology for the development of deformation hazard curves will provide a new and reliable approach for the seismic vulnerability evaluations of bridges. The guidelines describing the step-by-step procedure for the use of the methodology, which will be developed as part of this Proposal, will enable a wide use of the methodology by researchers in academia as well as by engineering analysts in design offices. The methodology will be developed in a general form and can be used in any country around the world. However, in the context of this Proposal, the application of the methodology for the seismic vulnerability evaluation of bridges in Canada is of special importance. The deformation hazard curves for bridges, developed based on the proposed methodology, can be used for ranking the bridges according to their vulnerability, and consequently for the development of seismic risk maps for bridges. In addition, the proposed methodology will be very beneficial for the improvement of the seismic provisions of the Canadian Highway Bridge Design Code. ******