既有桥梁加固方案的经济性分析

在既定资金约束条件下，应根据桥梁全寿命期内不同方案的经济净效益来选择合适方案。文章在考虑桥梁蜕化的基础上，提出基于抗力衰减的加固度概念，并在年收益既定假设条件下分别建立加固方案和重建方案的全寿命期费用模型以及两种方案的全寿命期比较费用及其年值模型。该模型为加固或重建方案的经济性选择提供了理论依据，就加固方案而言，还有利于确定资金约束条件下的最优加固度。

Economic Analysis of strengthening Schemes for Existing Bridge

With restriction of fund, choosing suitable scheme should be based on the net benefits of different schemes in entire life-span time of the bridge. Considering the decaying of bridges, this paper gives a concept of strengthening degree. With the assumption of established yearly earnings, it attempts to set up respectively entire-life-span- cost models and the comparative cost and annual magnitude of the two schemes. These models provide theoretical tool for strength- ening or reestablishing the scheme. As far as strengthening the scheme is eoneemed, these models may help to decide the economically suitable strengthening degree with limited fund.