Geogrid lateral load
GeosyntheticsMagazine.com | January 28, 2013
GMA techline answers from Bob Koerner
RE: Geogrid lateral load
I have proposed a GRS wall to replace a cut fill failure. Our geotechnical division says it will not hold the lateral load of the surcharge of a car or truck. It will be 6 feet deep, 8 feet wide, and 90 feet long. We will excavate to bedrock and provide drainage. It will basically be a benched trench to edge of pavement leaving the shoulder and slope intact. What do you think?
Reply: The question of sustaining surcharge loads from cars and trucks is modest in light of countless GRS (aka, mechanically stabilized earth walls) supporting railroads, bridge abutments, buildings, etc.
The typical design codes all include a routine for surcharge and many do so for static and dynamic loads as well. This is well within the state-of-the-practice at this point in time and can be implemented with confidence.
Furthermore, using the dimensions stated results in a 6/8, (or 75%), reinforcement length to height ratio which is reasonable for a GRS wall.