The coefficient Kae for active earth pressure is given by:
The coefficient Kpe for passive earth pressure is given by:
unit weight of soil
height of the structure
angle of internal friction of soil
angle of friction between structure and soil
back face inclination of the structure
seismic coefficient of vertical acceleration
seismic coefficient of horizontal acceleration
seismic inertia angle
Deviation of seismic forces ψ must be for active earth pressure always less or equal to the difference of the angle of internal friction and the ground surface inclination (i.e. φ - β). If the values ψ of is greater the program assumes the value ψ = φ - β. In case of passive earth pressure the value of deviation of seismic forces ψ must be always less or equal to the sum of the angle of internal friction and the ground surface inclination (i.e. φ + β). The values of computed and modified angle ψ can be visualized in the output - in latter case the word MODIFIED is also displayed.
Example of the program output
Mononobe N, Matsuo H 1929, On the determination of earth pressure during earthquakes. In Proc. Of the World Engineering Conf., Vol. 9, str. 176.
Okabe S., 1926 General theory of earth pressure. Journal of the Japanese Society of Civil Engineers, Tokyo, Japan 12 (1).