Effects of static loads on weldability repair/reinforcement by welding for steel bridges in service

Abstract

Experiments under static loads were carried out in order to investigate the possibility of repair/reinforcement by welding. Preventing the influence on the experimental devices due to the welding current by isolating between the jigs and the experimental devices, the stable experiments could be carried out. For the cruciform joints and I-shape joints, semi-auto CO2 gas welding was carried out under compressive static loads on the assumption of the dead load. As the experimental results, any cracks were not found. In the cruciform joints with multi-pass welding, there was a tendency that the longer the weld length became, the larger the magnitude of out-of-plane displacement became. In the actual construction, it was verified that repair welding under static loads could be carried out without welding defects by confirming repair weld length, heat input, inter-pass temperature and so on.