Seismic response of shallow‐floor buildings

Abstract

A framing system considered for a shallow-floor building to be used in seismic zones has wide shallow beams with sufficient stirrups. Two-way slab design is used for this system. This shallow-floor system is likely to have good ductile behavior as the beams deform inelastically. The lateral resisting system is designed with a 'strong column-weak beam' ductile frame configuration so that the hinging zones occur within the beams away from the face of the column. The beams will be substantially wider than the columns. The joint and hinge regions must have sufficient tie and stirrup reinforcement. P-delta effects should be considered but are not serious when drifts are controlled. The survivability of the ductile shallow-floor building under moderate earthquakes is studied. The serviceability, e.g., story drift, of the building is of concern. The usual case is that the building is likely to satisfy code requirements for base shear resistance and corresponding story drift limitation. Contrary to code prediction, the performance under a moderate earthquake often yields large story drifts which may severely damage the non-structural systems.