Seismic Fragility Analysis for Steel Staggered Truss Framing Structure Based on L-Moments

Seismic fragility analysis of steel staggered truss framing (SSTF) structures is carried out in this study. Instead of artificially assuming certain distributions for seismic demand and capacity models as in general methods, the seismic fragility is analyzed using the reliability theory considering the uncertainties in seismic excitation. First, the limit state function of SSTF is constructed. Next, the method of moments for fragility analysis is investigated, with a new discriminant proposed. The proposed discriminant aims to obtain sufficient ground motion samples for a thorough consideration of the seismic excitation. Then, seismic fragility analysis is performed on six typical SSTFs. The conclusions are as follows. The proposed discriminant can help to ensure the accuracy of seismic fragility analysis. Also, the arrangement of diagonal web in SSTF structure can significantly improve the fragility, and the fragility of rigid connection between vertical web and chord is less than hinged connection.