Structural frequency-based maintenance management method for steel truss bridges under atmospheric corrosion

Deterioration of steel truss bridges due to atmospheric corrosion can result in a degradation of performance that fails to meet basic safety requirements before the structure has fulfilled its design life. In order to prevent unexpected costs and premature structural damages caused by deterioration in steel truss bridges, cost-effective corrosion protection and maintenance strategies are required. In this study, a novel maintenance management method was proposed to keep the structural frequencies of steel truss bridges in between predefined boundaries throughout the service life. To pursue this aim, preventive and essential maintenance techniques were applied to provide appropriate atmospheric corrosion protection to steel truss bridges in a cost-effective way. Different repetitive repainting intervals were used for preventive maintenance, and member replacement alternatives with different ratios of total members were applied for essential maintenance approaches. Moreover, the replacement of members using conventional carbon steel, or A709-50CR was investigated separately. For the illustration of the proposed maintenance management method, a planar and a spatial steel truss bridge were selected from the literature, and maintenance strategies were applied considering two different corrosion classes. Life cycle cost analyses of steel truss bridges were conducted to evaluate different maintenance alternatives. Consequently, a cost-effective maintenance strategy was determined for each steel truss bridge in different corrosion environments.