众所周知,铁路和公路运输的车辆荷载都有不断增长的趋势。为了保证桥梁在其整个使用期限内的正常营运,桥梁主要构件的承重能力应能承受其使用后期增大了的荷载。由于桥梁的使用年限和承重能力之间这种明显的关系,确定最合理的使用年限,对正确地规定标准活载值有着重大意义,它直接影响构造物的初期投资及其营运费用。 As we all know, the railway and road transport vehicle load has a growing trend. In order to ensure the normal operation of the bridge throughout its useful life, the load-bearing capacity of the main components of the bridge should be able to withstand the increased load in its later use. Due to the obvious relationship between the service life of bridge and the load-carrying capacity, determining the most reasonable service life is of great significance for correctly setting the standard live load value, which directly affects the initial investment of the structure and its operating costs.