EARTHQUAKE RESISTANT DESIGN APPROACH TO MEET UNKNOWABLENESS OF SEISMIC GROUND MOTIONS

Abstract

The number of recorded seismic ground motions is increasing rapidly. However, the statistical data for the structural designers to determine the design ground motion for a specified site remain still far incomplete. While the structural damage may increase as the seismic energy input increases, the structure can remain uncollapsed as far as the sufficient energy absorption capacity is secured. Therefore, it is essential to prepare a sufficient energy absorption capacity for the structure to meet the unknowableness of the seismic input. In this paper, a set of seismic input is considered to cover the unknowableness of the seismic input, and the required strength and the maximum deformation is estimated by applying the energy approach. Framed structures are taken for example and it was found that the required base shear force coefficient can be determined uniquely regardless of the level of seismic input and the structural type(steel structure or reinforced concrete structure).