In 2008, a large retaining wall in Tulsa, Oklahoma failed.  The failure was attributed to a number of causes, all of them preventable by the retaining wall contractor.

A geogrid reinforced retaining wall is primarily geogrid and soil.  About 99 percent (roughly) of “The Wall” is the geogrid and the soil.  The geogrids act to stabilize the soil.  See this video for how geogrid works.

Anyway – the blocks on the front are just “erosion control”, ensuring that the geogrid and soil are not lost due to erosion.

At this project, as shown in this photograph, there are utilities everywhere!  The retaining wall contractor would have had problems building the wall because the utilities interfere with the geogrids.  There is a manhole riser (several feet in diameter) a gas line, water line, pipes, electrical ducts, irrigation lines, etc.  You name it, it was there!

The problem is: with all the “stuff” there was no room for the geogrid.  And without geogrid, there is no “Wall”You don’t have geogrid-reinforced soil, you only have “soil” and likely a mound of it. You just have a thin block veneer face that tips over … which is precisely what happened.


(State PE Registration Map)

Don’t let this happen to you!  Select your retaining wall contractor and designer carefully.

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