The following sign convention is used in the program, text and presented expressions.
Sign convention for calculation of earth pressures
- inclination of the ground surface β is positive, when the ground rises upwards from the wall
- inclination of the back of structure α is possitive, when the toe of the wall (at the back face) is placed in the direction of the soil body when measured from the vertical line constructed from the upper point of the structure
- friction between the soil and back of structure δ is positive, if the resultant of earth pressure (thus also earth pressure) and normal to the back of structure form an angle measured in the clockwise direction