Definition of thrust and abutment forces
Retaining walls – Active and passive earth pressure

For a simple retaining structure, such as a concrete wall holding back a soil mass (figure 1 ), the types of stresses exerted on the wall are :

• the force of gravityW , the weight of the wall, exerted on the face of the wall in contact with the ground;

• the three forces of soil mechanics :

  • the thrust force (or thrust) and is noted P _a , the subscript a specifying that it is an active force. It is the force of the soil mass exerted on the upstream face of the wall and which tends either to topple the wall or to move it horizontally,...