There are two types of walls to consider when asked the question “what makes a retaining wall work?” Gravity walls and reinforced walls. First, let’s look at gravity walls.
Gravity walls require two things to perform well – the Allan Block unit (its weight) and the setback the unit has. What is “setback?” Setback is the degree to which a retaining wall “leans” back from vertical as shown in the gravity wall section below. This setback, coupled with the weight of the block itself, will allow the wall to perform as it should in a “gravity wall” application. Check out our setback charts for additional information.
Reinforced walls require three things – the Allan Block unit (its weight), setback, and geogrid. Since we have identified what setback is, the only potential unknown is geogrid. Geogrid is a woven textile that has been used to strengthen soil for decades. Reinforced segmental retaining walls utilize geogrid to strengthen soil and create a mass heavy enough to resist the active forces of the soil behind the wall, ultimately allowing us to build taller walls. A typical reinforced Allan Block section is here:
To learn more about gravity walls or reinforced walls please visit allanblock.com and/or call us today to discuss in more detail.