Active Earth Pressure - The Caquot Theory
Active earth pressure is given by the following formula:
where: | σz | - | vertical geostatic stress |
cef | - | effective cohesion of soil | |
Ka | - | coefficient of active earth pressure | |
Kac | - | coefficient of active earth pressure due to cohesion |
The following analytical solution (Boussinesque, Caquot) is implemented to compute the coefficient of active earth pressure Ka:
where: | Ka | - | coefficient of active earth pressure due to Caquot |
KaCoulomb | - | coefficient of active earth pressure due to Coulomb | |
ρ | - | conversion coefficient - see further |
where: | β | - | slope inclination behind the structure |
φ | - | angle of internal friction of soil | |
δ | - |
The coefficient of active earth pressure Kac is given by:
for: 
for: 
where: | φ | - | angle of internal friction of soil |
δ | - | ||
β | - | slope inclination behind the structure | |
α | - | back face inclination of the structure |
Horizontal and vertical components of the active earth pressure become:
where: | σa | - | active earth pressure |
δ | - | ||
α | - | back face inclination of the structure |