# 11.9.2 Vertical Elastic Design Spectrum

Using the coefficients obtained from the map, the spectrum curve is automatically made with Equation 11.9-1, 11.9-2, 11.9-3 and 11.9-4 by the program.

The design vertical response spectral acceleration, S_{av}, is taken as two-thirds of the value of S_{aMv}.

**SYMBOLS**

* S_{MS} =* The MCE

_{R}spectral response acceleration parameter at short periods

*= The vertical response spectral acceleration*

**S**_{aMv}*The design vertical response spectral acceleration*

**S**_{av}=*The vertical period of vibration. [s]*

**T**_{v}=*is defined in terms of S*

**C**_{v}=_{S}in Table 11.9-1

With the spectral response acceleration parameters obtained from USGS depending on the coordinates, the vertical response spectrum **S**** _{aMv} **is

*calculated according to the formula below.*

For vertical periods less than or equal to 0.025 s, S_{aMv} is determined with eq. 11.9-1.

For vertical periods greater than 0.025 s and less than or equal to 0.05 s, S_{aMv} is determined with eq. 11.9-2.

For vertical periods greater than 0.05 s and less than or equal to 0.15 s, S_{aMv} is determined with eq. 11.9-3.

For vertical periods greater than 0.15 s and less than or equal to 2.0 s, S_{aMv} is determined eq. 11.9-4.

Vertical coefficient, C_{v} is determined according to Table 11.9-1 with using straight-line interpolation for intermediate values.

The design vertical response spectral acceleration, S_{av}, is taken as two-thirds of the value of S_{aMv}.