Historical research on the process of the development of steel bridge construction industry

Steel bridge industry expanding for about 40 years has reached its peak at the end of 20th century. 600 to 900 thousands ton of steel were fabricated every year for bridge construction in 1990s, which had exceeded the total amount of the construction in America and Europe. Development of knowledge and technology of steel material, high tensile strength bolt, welding and devices for fabrication and erection and also computer technology has been making increase the efficiency, the quality and the safety of bridge construction. Procurement system for steel bridge construction had started to change in 1990s.In this paper the process of the development of steel bridge construction is clarified and the characteristics of Japanese steel bridge industry has been researched from the comparative viewpoint between Japan and western countries.