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桥梁地震易损性评估方法。该方法基于变形危险曲线的使用，该曲线代表不同变形水平(从弹性变形到坍塌)的年平均超限概率。与目前使用的脆性曲线相比，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反应，并包括桥梁位置的地震危险的影响。响应由选定的单个整体变形参数来量化，桥梁位置的地震危险性由不同烈度水平的年度超越概率来表示。变形参数和烈度量度是该方法中的关键参数，并对这些参数的选取进行了专门的研究，建立变形危险曲线的方法将为桥梁的地震易损性评估提供一种新的可靠方法。将作为本提案的一部分制定的关于使用该方法的循序渐进程序的准则，将使学术界的研究人员以及设计局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，在这项提议的背景下，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。基于该方法建立的桥梁变形风险曲线可用于根据桥梁的易损性对桥梁进行排序，从而制定桥梁地震风险图。此外，所提出的方法将非常有利于加拿大公路桥梁设计规范中抗震条款的完善。

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.