FS = Local ground impact coefficient for the short-period region
F1 = Local ground impact coefficient for a period of 1.0 seconds
SDS = Short-period design spectral acceleration coefficient [dimensionless]
SD1 = Design spectral acceleration coefficient for a period of 1.0 seconds [dimensionless]
SS = Short period map spectral acceleration coefficient [dimensionless]
S1 = Map spectral acceleration coefficient for a period of 1.0 seconds [dimensionless]
T = Natural vibration period [s]
TA = Horizontal elastic design acceleration spectrum corner period [s]
TB = Horizontal elastic design acceleration spectrum corner period [s]
TL = Transition period to constant displacement region in horizontal elastic design spectrum [s]
Sae (T) = Horizontal elastic design spectral acceleration [g]
The map spectral acceleration coefficients Ss and S1 values of the coordinates, specified at General Building Informations, are obtained from AFAD earthquake map data using the Analysis Wizard online option.
Local soil effect coefficients are obtained from TBDY 2018 Table 2.1 according to ZC local soil class specified in the geotechnical report and the design spectral acceleration coefficients are calculated automatically by the program.
The horizontal elastic design spectral accelerations Sae(T), which are the ordinates of the horizontal elastic design acceleration spectrum for any earthquake ground motion level considered, are defined in terms of gravitational acceleration [g] depending on the natural vibration period.
Based on the coordinates, the spectral acceleration coefficients obtained from AFAD and the horizontal elastic design spectrum Sae(T) are determined according to the formula below. For the horizontal elastic design spectrum, it is represented by a total of 4 functions, different in each region, is shown in the graph below.
In order to create the spectrum, the time should be increased with appropriate intervals starting from 0 seconds and stopped at an appropriate T value after TL=6 s. For this building, the horizontal elastic spectrum starting from T=0 s to T=8 s with 0.05 intervals is calculated in the excel. The obtained spectrum is given in the image below.