中文摘要：

展开寿命周期内拉索劣化规律和维修更换策略的研究，获得桥梁结构的最优成本一效益比，是缆索桥梁养护维修的重要研究内容之一。根据拉索寿命函数和拉索系统的串并联模型，研究斜拉桥拉索系统失效概率变化即结构劣化的规律，分析全寿命周期内不同维修更换措施对结构失效概率的影响。运用周期成本理论，进一步分析不同维修更换时间和更换策略的经济性。结合一斜拉桥模型，验证了模型的适用性，并且以延长使用寿命和累积维修费用最低为目标，获得该桥的最优维修策略。研究表明，寿命函数和周期成本理结合是确定斜拉桥拉索更换优化策略的有效途径，为工程拉索更换策略提供有益的参考。

英文摘要：

Study on the deterioration of the stay-cables as well as the optimum maintenance strategies to get the best cost- benefit ratio throughout the life of the structure is always one of the most important issues in bridge engineering. Based on the lifetime functions of the stay-cables and the series-parallel cable system model, the failure probability of cable-stayed bridge and the structure deterioration was studied, and the effect on the failure probability by different maintenance and replacement strategies was analyzed. Using lifetime cost theory, the timing and the economy of the replacement of the stay-cables was further analyzed. With the application to a cable-stayed bridge, the applicability of the models was tested, the optimal replacement strategy is recommended with the objective of maximum life time and minimum maintenance cost. It shows that the life-cycle cost theory based on the lifetime functions of the whole cable system is an effective planning method for replacement of stay-cables.