江阴大桥是我国首座跨径超千米的特大型钢箱梁悬索桥,是国家“九五”期间重点建设项目,代表着我国20世纪桥梁建设的最高水平。大桥通车以来车流量逐年增长,日均流量从开通之初的1.3万辆增加到目前的4.2万辆,经济和社会效益显著。然而,大桥在运营过程中,由于过载、疲劳效应、外来冲击等作用,以及材料的自然老化等自然或人为的 Jiangyin Bridge is the first large-span steel girder suspension bridge with a span of over 1000 meters in China. It is a key construction project during the “95” period of China and represents the highest level of bridge construction in the 20th century in our country. Since the opening of the bridge, the traffic volume has been increasing year by year. The average daily traffic volume has increased from 13,000 at the beginning of the opening up to 42,000 at present, which has remarkable economic and social benefits. However, during the operation of the bridge, due to overload, fatigue effects, external shocks and other natural and man-made effects such as natural aging of materials