ABSTRACT
The majority of buildings are analyzed and designed in accordance with the building codes. An introduction to the historical development of the US and international building codes is given by Berg[1]. Typically, the earthquake loading is defined in terms of an equivalent lateral force, and a static analysis of the building is performed. In recent years, building codes have adopted more and more features of the formal dynamic structural analysis, while retaining their original formats. Perhaps the most popular and relatively rigorous building code presently in use in the profession is the Uniform Building Code (UBC)[2]. The seismic design and analysis requirements of the UBC are based on the procedures developed by the Structural Engineers Association of California (SEAOC)[3]. The developments of the UBC and the SEAOC requirements have been gradual and evolutionary in nature. In a somewhat different approach, the Applied Technology Council, a research and development organ of the SEAOC, undertook to produce a model seismic code development in 1974 under the sponsorship of the National Science Foundation. The effort was coordinated by the National Bureau of Standards. Nearly a hundred scientists and engineers contributed to the project report, ‘Tentative Provisions for the Development of Seismic Regulations for Buildings’, popularly known as ATC3–06, or simply as ATC3[4]. The report is being reviewed by engineers and building officials to evaluate its utility, cost and effectiveness in leading to earthquake resistant structures.
