Earthquake-Resistant Engineering of Steel Structures

Steel structures are predominant in building construction in Japan. As shown in Fig. 8-1, steel structures increased rapidly after World War II and at present account for about 40% of the total floor areas of newly constructed buildings in a year. This ratio is comparable with wooden structures, while concrete structures are limited to about 20%. Such a high share of steel in building construction is unique in the world. The reason why steel buildings are so popular in Japan may be found in the strong support the government gave to developing the steel industry soon after the Meiji Restoration. The policy invited an extraordinary advancement of the technology of applying steel materials to various industrial products. At the same time, however, another important factor cannot be neglected: Japan is an earthquake-prone country located in one of the most quake-hazardous regions on Earth. Thus, the basic idea of structural design has been established: that strong and tough materials should be used in building structures to resist the impact of severe earthquakes. Obviously, steel is the best material to fit such requirements. Although steel is more expensive than concrete and timber, the practice of employing it in buildings has been sustained by the national wealth of Japan