Enter the unit weight of the soil, height of the wall, and the coefficient of active earth pressure into the calculator to determine the active earth pressure.

Active Earth Pressure Calculator

Enter any 3 values to calculate the missing variable

Active Earth Pressure Formula

The following formula is used to calculate the active earth pressure for a given set of variables. 

P_a = 0.5 * γ * H^2 * K_a

Variables:

  • Pa is the active earth pressure
  • γ is the unit weight of the soil (N/m³)
  • H is the height of the wall (m)
  • Ka is the coefficient of active earth pressure

To calculate the active earth pressure, multiply 0.5 by the unit weight of the soil, the square of the height of the wall, and the coefficient of active earth pressure.

What is Active Earth Pressure?

Active earth pressure is the pressure exerted by soil onto a retaining wall when the wall moves away from the soil mass. This type of pressure is a crucial consideration in the design of retaining structures, as it influences the stability and structural integrity of the wall. The active earth pressure depends on factors such as the unit weight of the soil, the height of the wall, and the coefficient of active earth pressure, which is determined by the soil’s properties and the wall’s inclination.

How to Calculate Active Earth Pressure?

The following steps outline how to calculate the Active Earth Pressure.

  1. First, determine the unit weight of the soil (γ).
  2. Next, measure the height of the wall (H).
  3. Next, determine the coefficient of active earth pressure (Ka).
  4. Finally, calculate the active earth pressure using the formula Pa = 0.5 * γ * H² * Ka.
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Unit weight of soil (γ) = 1800 N/m³

Height of wall (H) = 5 m

Coefficient of active earth pressure (Ka) = 0.3