DESIGN STRATEGIES FOR STEEL STORAGE RACKS IN SEISMIC ZONES

The use of storage racks is remarkably increased in the last years mainly because of i) the growing importance of the logistic in the context of the global economy and ii) the high levels of standardization of key rack components. A parametric analysis on braced and unbraced racks in seismic zone is presented in the paper. On the basis of a geometric layout of interest for routine design, rack performance has been evaluated via two alternative design approaches: the well-established modal response spectrum analysis and an advanced strategy combining non-linear time-history analyses with the assessment of the damage in joints. Reference is made to two recent Italian earthquakes scaled by different values of the peak ground acceleration. Furthermore, cyclic joint behavior has been reproduced by means of a suitable model accounting for joint strength/stiffness degradation.