# Site Class and Site Coefficients

The floor type is chosen by the user.

Coordinate selection is made from the map.

If you use the online option, the spectrum coefficients from the AFAD map are processed online.

If you use the offline option, the spectrum coefficients in the program database are automatically processed.

Spectrum parameters are determined automatically using Equation 2.1.

**ICONS**

* F _{S }= *Local ground impact coefficient for the short-period region

*Local ground impact coefficient for a period of 1.0 seconds*

**F**_{1 }=*Short-period design spectral acceleration coefficient [dimensionless]*

**S**_{DS }=*Design spectral acceleration coefficient for a period of 1.0 seconds [dimensionless]*

**S**_{D1 }=*Short period map spectral acceleration coefficient [dimensionless]*

**S**_{S }=*Map spectral acceleration coefficient for a period of 1.0 seconds [dimensionless]*

**S**_{1}=**Local Soil Impact Coefficients **

**TBDY 2018 According to Table 16.1** , the average shear wave velocity **( ****V **** _{S30} )** , the average standard penetration impact number

**(**

**N****or the average undrained shear strength**

_{60})_{30}**(**

**c**

_{u})_{30}_{ }, depending on the ZA - It has been defined as six classes, ZF.

**Depending on the ***local soil classes* defined in **TBDY 2018 16.4** , **local soil impact coefficients F **** _{S} **and

**F****are given in**

_{1}**Table 2.1**and

**Table 2.2 ,**respectively . Linear interpolation is performed for intermediate values of map spectral acceleration coefficients in the tables.

**2.3.3.2 - Table 2.1** and / or **Table 2.2** according to the ground entering the ZF site classes **s *** AHAs specific soil behavior analysis* must be performed.

In the Analysis Settings Wizard - Design Spectrums tab, design acceleration coefficients are obtained with the map spectral acceleration coefficients obtained depending on the coordinate with online and offline options. If the online option is used , acceleration coefficients are obtained from the *AFAD Earthquake Hazard Map* . In the offline option, the acceleration coefficients calculated over the program infrastructure are obtained. Both options give the same results.

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