ABSTRACT
Formerly, field welding generally performed the joining works of steel pipe piles. However, since such welding has the problems (1) that the execution time is comparatively long and this tendency increases as the external diameter or wall thickness of the steel pipe increases, (2) that the work cannot be executed under bad weather conditions; such as rain, strong wind, etc., (3) that careful control and highly skilled welders are required to ensure the quality, and other problems.
