Current Research

The strength of the wall varies depending on factors such as the materials used, the design of the wall and the type of soil behind the wall. However, one factor remains constant between all walls, water pressure behind the wall. This factor can make or break most walls. The toe wall's defense is proper irrigation.Without this system, the wall is bound to have a short lifespan.

"Built right, he says, a retaining wall can outlast most people. But like any structure, their lifespan depends on how they're built. A wall built of railroad ties isn't likely to last as long as one made of concrete blocks, but even a concrete block wall can fail early. A lot of factors play into lifespan including: the soil type behind the wall, drainage around the wall, the material the wall is made of, and how strong the wall's foundation is.

"There's a lot of different ways to design [walls]," he says. "Ensuring that there's low water and water pressure behind [the wall] is critical.""

Walls Come Tumbling Down, J. Adrian Stanley, (Article found Here)