Episode 1 – Mechanically Stabilized Earth (MSE) Walls: What Can Go Wrong on Site

Not long ago, I passed by a construction site and noticed something in the photo below that raised my concern.

The uniaxial geogrid, used to reinforce the backfill behind the wall, was placed with its strong direction parallel to the wall face.

That’s a serious mistake.

Uniaxial geogrids are designed to resist tensile forces in one primary direction. That direction should always be placed perpendicular to the wall, extending into the retained soil.

When installed incorrectly (as shown below), the grid loses nearly all its intended reinforcing capacity.

This might go unnoticed for low-height walls, but for taller walls, this kind of misplacement can lead to progressive deformation or even failure.

This highlight two critical messages:
(1)   Design drawings and specs must clearly show not just the materials, but also their correct orientation and installation guidelines.

(2)   Field review teams should also be aware of what to look for. Because even a correctly supplied product won’t perform if it’s installed the wrong way.