Load Carrying Capacity Old Steel Girder with Considering Corrosion Effect of Steel Material

There are many steel girder bridges that have been operated for a long time, particularly on the national railway system. These structures have not been maintained and repaired with a reasonable level which led to rust of steel girder. Corrosion has made a decrease of a cross-section along with the length or at local areas of steel girder; A significant degradation of the loading capacity of steel girder which could seriously affect the safety of these bridges. Rely on verification for structures, parameters of material, rust condition and detailed dimensions of the girder, service load is determined. Analyzing and summarizing these parameters have estimated the general condition of rust and loading capacity of operative constructions. Additionally, numerical simulations according to the finite element method to investigate the loading capacity of steel girder with relevant parameters of rust condition such as depth of rust layers, rust position and rust area have been implemented as well. Non-linear analyses have also been performed to determine the behavior of steel girders under loading. Results of investigation would assist to induct regulation of the operation, solution of repairmen.