Episode 2 – Mechanically Stabilized Earth Walls MSEW: Is 750 kPa Really Too Much?

A few years ago, I reviewed a project where the ultimate bearing pressure beneath an MSE wall was reported as 750 kPa.

At first glance, it felt off.

We're used to seeing values in the range of 100 to 200 kPa for typical footings, so I asked, “Why is it this high?”

But once I stepped back and considered the context, it started to make perfect sense.

This was not a regular wall.
It was a 16-meter-high MSE wall, and that comes with significant overburden pressure plus additional stress due to wall overturning and non-uniform load distribution.

Now, is 750 kPa still high?
Yes (without context).

But in this case, the base reinforcement layer extended about 12 meters, and both the ultimate and factored geotechnical resistances were well above the applied loads.
So from a ULS standpoint, it was completely acceptable.

What about settlement?

We were also dealing with high SLS pressures, but the foundation soils were naturally very dense, and we completed a PLAXIS 3D analysis to account for the complex geometry and loading.
The predicted settlements fell within tolerable limits.