文章以现行公路桥梁设计荷载为基础，采用后继服役期超越评估荷载的概率等于设计使用期超越设计荷载概率的原则，给出了现有公路桥梁结构可靠性评估时可变荷载取值的修正系数；利用时变安全可靠度理论，对现有结构的剩余寿命进行评估，提出了对可变荷载取值进行修正的方法。

On the basis of design load in force, the revised factors of variable load used in estimating existing bridge structures are given according to the theory, which is the probability that the load used exceeds the reservice term should be equal to the probability that the load used in design exceeds the service term. The theory of time-dependent ability is adopted to evaluate the residual service life of structure and a method is adopted to revise the variable load.