Retaining wall is a structure, which holds back soil or rock from a building, structure or area. It prevents downslope movement or erosion and provide support for vertical or near-vertical grade changes. These are generally made of masonry, stone, brick, concrete, vinyl, steel or timber. The most important consideration in proper design and installation of retaining walls is that the retained material is attempting to move forward and downslope due to gravity. This creates a soil pressure behind the wall which depends on the angle of internal friction (phi) and the cohesive strength (c) of the retained material, as well as the direction and magnitude of movement the retaining structure undergoes.