Abstract
In recent years, it has been discussing about reducing cost and labor in bridge fabrication. These are the most important subjects at present. As the way of reducing this cost, automatic welding or high-efficiency welding will be used increasingly. Automation has recently extensively developed in many factories, however, it is only few case using highefficiency welding. For this reason, Specifications for Highway Bridge regulates limited-heatinput( maximum heat input is 70KJ/cm on SM570). In this paper, based on many technical reports which is reported so far, it is investigated charpy absorbed energy by using high-heatinput welding. From the results of this investigation, the authors propose limited-heat-input. Finally, application of high-heat-input welding is described in steel bridge fabrication.