中文摘要：

通过定义桥梁及桥梁构件的设计使用寿命，对桥梁构件进行按结构体系划分和耐久性设置研究.调查了国内外桥梁结构及构件的实际工作寿命和规范指南中的设计使用寿命建议值，提出了基于寿命周期成本分析法的确定桥梁结构构件设计使用寿命的直接方法和简化方法.直接法首先为构件制定寿命方案，通过计算各寿命方案的寿命周期成本，选择经济性最优的方案；在简化法中给出了设计使用寿命简化计算公式，对影响系数进行了划分及取值讨论，并给出了基于专家调查的构件基础设计使用寿命建议值.最后，以某跨海工程为例，系统地演示了桥梁结构构件设计使用寿命的确定流程.

英文摘要：

Through definition of design service life for bridges and their elements,components classification according to structural systems,durability type research as well as investigations of their actual operating lives and recommended design service lives in specifications home and abroad,a direct method and also a simplified one were proposed to determine design service life of bridge structural elements based on the life-cycle cost analysis.As for direct method,element service life schemes were established,and then the one with optimal economy can be selected through life cycle cost calculation of each scheme.As for the simplified method,a calculation formula was presented for classification and evaluation of the influence coefficients and foundational design service lives of bridge elements were recommended based on professional investigations.Finally,a sea-crossing project was taken as an example to illustrate the process of design service life determination for bridge structural elements.