Typically MSE walls materials only are about $12 to $13 per square foot. This is for the panels and hardware. You must include the installation of the MSE materials, furnish and installing the backfill behind the MSE. There are different types of backfill ranging from aggregate to lightweight foam concrete. The lightweight foam concrete has recently been comparative to the price of conventional backfills and offers many advantages in the design and construction of MSE walls.
I just received unit costs from a Contractor in Seattle for MSE walls @ $18 / sf. This, however, would be for height ranges from 4 - 20 feet, but would include reinforcment. sorry, I don't have costs for 40 foot high.
However, we too just prepared very preliminary plans that include MESA walls to 30 feet. If you do find some better estimates for the higher walls, I would appreciate it if you could let me know.
We did a wall in Puerto Rico with Keystone units and steel reinforcement with a total height of 65 ft with near vertical setback. Cost of materials for the wall were about $12.80/sf. Installation was close to $10/sf. The material for backfill at the reinforced zone (A-1-a) which was 46 ft long was available from the site.
With high walls and polyester reinforcements (we have done walls up to 42 ft height with Keystone Standard units and Mirafi geogrids) the cost of materials goes up to $16/sf.
When you design a MSE wall, there are many variables involved in the analisys, that makes it very difficult to establish a typical cost per sqft. Issues like global stability, access to the site, existing ground materials,etc. can impact your design so heavily that you can have a wall 18 ft as well as anotherwith 10 ft height with the same cost.
Cordially,
Jorge L Morales, P.E
jlmmsed@aol.com
