Design of reinforced concrete buildings according to the new NEHRP provisions

Abstract

This paper examines the seismic analysis and design requirements for earthquake resistant reinforced concrete buildings according to the recent NEHRP recommended provisions, also known as FEMA 450. To demonstrate the implementation of the NEHRP provisions, a case study reinforced concrete building is analyzed and designed. A number of key modeling and design considerations are examined such as: (1) the effects of upper and lower limits imposed by the provisions on design fundamental period; (2) the variation of drift along the height of the building in a structure that contains a dual lateral force resisting system in one direction and a moment resisting frame in another direction, compared to the limiting NEHRP value; (3) comparison of the torsional irregularity limit in the provisions to finite element computations for dual lateral resisting system as well as special moment resisting frame system; (4) the effects on structural response of the interaction of shear-wall and special moment resisting concrete frames.

Keywords: Seismic Design, NEHRP Provisions, Dual Systems, Torsional Irregularity.