# Vertical Distribution of Seismic Forces (4.7.2)

The earthquake load equivalent to the effect on the floors for each direction is calculated automatically using

**Equation 4.21 - 4.22 - 4.23**.

* m _{i} =* Total mass of the relevant storey

*(X) Equivalent earthquake load acting on the center of mass of the i'th storey in the earthquake direction [kN]*

**F**_{iE }^{(X) }=*= height of the i'th storey [m]*

**H**_{i }*The upper section above the basement floors of the building The total number of floors in*

**N =***(X) additional equivalent earthquake load acting on the Nth floor (top) of the building in the earthquake direction [kN]*

**F**_{NE }^{(X)}=The additional equivalent earthquake load acting on the Nth floor (top) of the building is calculated by the following equation:

The peak load is

used to approximate the effect of high modes neglected in this method . The total equivalent earthquake load (Base shear force) is calculated by the following equation.

The part of the total equivalent earthquake load other than the peak load

is automatically distributed to the building floors, including the Nth floor, by accepting the mode shape of the dominant mode as an inverted triangle.