To complete the seismic analysis according to the rules given in this code, define the following parameters: The maximal period is calculated according to the formula:Ĭu - Upper Limit Coefficient (Table 12.8-1), If this option is on, one of modes, which fulfill limitations and most masses is active in the direction. If the option Periods with maximal mass participation is off in the Seismic Analysis dialog, the first mode in direction where more masses is active. Only Ta on both directions is to be defined.Īccording to this method you can calculate the exact value for both X and Y directions. H - structure height (m), defined by difference between Structure range and Reference level X = building period formula exponent (given by the code) The fundamental period Ta is calculated according to the equation 4.6:Ĭ t - building period coefficient depending on the type of seismic-force-resisting system that is used (given by the code) The calculation of the fundamental period (Ta) depends on the method selected in the Seismic analysis dialog.

Asce 7 chapter 20 pdf