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Gravity Wall 

GEO5

Geotechnical software

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Mononobe–Okabe theory

The coefficient Kae for active earth pressure is given by:

The coefficient Kpe for passive earth pressure is given by:

where: γ - unit weight of soil
H - height of the structure
φ - angle of internal friction of soil
δ - angle of friction structure - soil
α - back face inclination of the structure
β - slope inclination
kv - seismic coefficient of vertical acceleration
kh - seismic coefficient of horizontal acceleration
ψ - 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 outputExample of the program output

Literature:

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)

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