Assessment of floor accelerations in special steel moment frames

• This paper examines the assessment of floor accelerations in Special Moment Frames.
• Different modeling options having different levels of complexity are considered.
• Particular attention is paid to the influence of the gravity system.
• Some aspects of the design floor accelerations indicated in ASCE 7 are evaluated.
• Expected floor accelerations in SMFs located in high seismicity areas are appraised.

The floor acceleration response of Special Steel Moment Frames subjected to earthquakes is evaluated considering different modeling options, i.e., elastic and inelastic behavior, with and without gravity frames, and considering different strength levels of the partially restrained connections in the gravity frames. The characteristics of the Special Steel Moment Frames considered in this study are based on those considered in the ATC 76-1 project. The influence of each modeling option on peak floor accelerations and on floor response spectra is then investigated. Results are also compared with the design acceleration demands on nonstructural components indicated in ASCE 7, which leads to relevant observations.