On the seismic behavior of multi-story frame structure excited by near-fault ground motions

The seismic response process of a 12-story reinforced concrete frame structure under near-field pulse-like and non-velocity pulse ground motion has been investigated by comparison in the paper. It is analyzed on the influence of near-field pulse-like ground motion to the seismic response of the frame structure from elastic into elastic-plastic stage. The results show that the elastic seismic response of the structure is no significant difference under near-field pulse-like and non-velocity pulse ground motion. However, the structure response under near-field pulse-like is larger than under non-velocity pulse in elastic-plastic stage, particularly the top story displacement, the storey drift and the basic shear who will obviously increase. The response spectrum in current code cannot sufficiently represent the effects of elastic-plastic seismic response to the structure under near-field pulse-like ground motion. The near-field pulse-like ground motion contains generous low frequency components and the spectrum values attenuate slowly along with the period. Hence, the spectrum values are greater and it has distinct influence on long period structures than short period structures.