Direct displacement-based design of special concentrically-braced frames in near-fault regions

Abstract

The effect of near-fault earthquakes on the effective period of special concentrically-braced frames is studied in this paper. The effective period is one of the most important parameters in direct displacement-based design. Given the effective period, the design base shear of structure can be obtained. Since the braced frames have high stiffness, an appropriate category of near-fault earthquakes for structures with high stiffness is established in this paper and the relations are presented to determine the pulse period and peak ground velocity. Sixteen near-fault accelerograms are simulated by the proposed methodology and applied to 16 one-storey special concentrically-braced frames. The results show that the behaviour of frames subjected to earthquakes with magnitude 6. The effective period depends on pulse period, peak ground velocity, ductility and design displacement. Two expressions are suggested to determine the effective period of two types of special concentrically-braced frames (X-braced and Inverted V-braced frame) according to these parameters.