本文主要利用貝氏理論修正理論，提出一套可對建立的橋梁易損性曲線做客觀性的修正，對於地震對橋梁所造成的直接災害損失，做一合理且可靠的評估。 主要內容為介紹建立橋梁易損性曲線的方法，分為問卷調查的方法及利用簡化理論的方法。問卷調查方法的準確性包含了專家對於問題的自信程度與經驗程度，並以此做為權重分配的標準。簡化理論的方法則是依據橋梁的相關基本資料，如混凝土強度、鋼筋強度….，求得剪力容量，並了解橋址座落位置上的土壤性質，依據不同損害度的反應譜折減係數，可得到易損性曲線的損害門檻值，便可建立橋梁易損性曲線。由實際損害資料的取得，進一步將原先的易損性曲線做客觀的修正。橋梁易損性曲線的建立便可結合地震超越或然率，了解475年回歸期地震時及使用年限內橋梁的各損害度或然率，亦可對於橋梁座直接經濟損失評估，並列舉二件範例來說明橋梁直接經濟損失評估之流程。 The purpose of this thesis is to build up an engineering risk model of earthquake loss estimation and its application to estimate the direct bridge loss. This estimation methodology integrated the seismic hazard analysis and fragility analysis. A Bayesian analysis method for updating earthquake ground motion versus damage relationship in the form of fragility curve is proposed. As bridge damage data from past earthquake gradually become available. And the simplified analytical method is also developed to obtain fragility functions of classical bridges. Experience from the experts on bridge damage is used with the damage relation developed through simplified analytical method to estimate the prior distribution. The Bayesian updates scheme is then adopted to obtain the posterior distribution of the fragility curves.
