Landscape Architect Articles

Unstable Wall Secured, Given Face Lift06-16-09 | News

Unstable Wall Secured, Given Face Lift

The secure the moving wall, eight-inch diameter holes were bored into the soil behind the wall, then 80-100-foot-long cables lowered into the holes and grouted. Flat-metal rings were installed over the holes. By pulling on the plates with a large machine the cables forced the retaining wall back into place. Large steel nuts were then attached over each plate to secure the wall?EUR??,,????'?????<

A popular Wal-Mart store in Corona, Calif. was surrounded by a large, stacked block wall 1,400 lineal feet in length and more than 20 feet high. Unfortunately, movement was discovered in the wall and the safety of several homes above and behind the wall was threatened.

Baldwin Construction, a drilling contracting company from Carlsbad, Calif. was hired to anchor and stabilize the wall. A tieback system was employed. Multitude deep holes eight inches in diameter were bored into the soil behind the wall, then 80-100-foot-long cables lowered into the holes and grouted. Large, flat-metal rings were installed over the holes. A large machine pulled on the plates, which then slid the cables, forcing the retaining wall back into its proper position. To permanently hold the wall, large steel nuts were attached over each plate.

The homeowners were pleased the wall was secure, but the wall had a raw, unfinished look. Large, ugly steel plates were visible everywhere, sticking out sometimes 10-12 inches throughout the entire length and height of the wall.

An affordable and attractive design solution for the secured but now ugly wall was applying and sculpting layers of architectural shotcrete to give a fractured, sandstone look to the wall, then applying a stain.

The folks at Wal-Mart wondered how such a significant architectural element surrounding the store might be made more aesthetically pleasing. What options were available? An initial thought was cast-in-place concrete to create a new face to the wall. Such an effort was considered too time-intensive and expensive. A more affordable and faster solution was sought.

Boulderscape had been involved with the project from the beginning and had a long-standing relationship with Baldwin Construction. Steve Jimenez, vice president of commercial sales at Boulderscape had assessed the wall months before stabilization work began. Because there were no geological features nearby to replicate, Jimenez decided a sandstone finish with some natural looking cracks could make the wall appear as if it were a recently excavated slope.

Photo simulations done in Photoshop showed what the wall would look like with a custom designed shotcrete finish. The Wal-Mart executives liked what they saw and the face-lift began.

There were three key steps. First they installed an eight-inch layer of structural shotcrete to the wall face section by section. A second architectural shotcrete layer one to three inches thick was then applied. While the shotcrete was still wet, artisans free-hand sculpted a fractured, sandstone look. The final step was an application of stain, which brought the colorless surface to life. The makeover took six experienced team members 14 days, typically half the time it would have taken with other types of wall finishes.

This solution also saved Wal-Mart money.

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Jimenez pointed to the collaborative attitude of everyone involved for creating an aesthetically pleasing retaining wall that is now safe and secure.