Terraced walls are a common feature in retaining wall applications. From an engineering standpoint, these walls must be treated as a single composite structure if their proximity, in conjunction with other site and soil parameters, is such that an upper wall places additional load or stress on the wall (or walls) below.
Most terraced walls may be considered independent of each other if they meet the requirements of the following rule of thumb.
Terraced Wall “2:1” General Rule
“Terraced walls may generally be considered independent of each other if… 1) the height of the upper wall is less than or equal to the height of the lower wall and… 2) the distance between the two walls is at least twice the height of the lower wall.”
This general rule may not apply if soils are very poor, if toe or crest slopes are involved, or if there are additional surcharges present.
Terraced walls that do not meet the “2:1” rule usually require additional mass and / or soil reinforcement incorporated into the lower wall design in order to resist the additional stress incurred from the upper wall or walls.
>= 26’ 8”
Terraced Wall Example