Reinforced Retaining Wall Makes Way for New Housing

THE CHALLENGE

Numerous grade changes and limited space were preventing construction of The Argonne Development in Idaho, which includes the Northwood Heights Apartments. To construct this massive complex, a large retaining wall was required to create flat, usable land on the side of a hill and maximize space.

However, there were numerous inclines as the wall went up the street and limited space in which to construct the wall. An additional consideration was that the client wanted the stone to match the natural boulders surrounding the area.

"The land had remained undeveloped despite many surrounding developments due to the great elevation difference over the site and the sand soils, which caused a stability issue," said John McKervey, P.E, Project Engineer, JM Engineering.

THE SOLUTION

"The introduction of the PC (Positive Connection) wall system from Redi-Rock provided a cost effective solution for the development of the site'' said McKervey. "Smaller blocks require more time to install and more geogrid to provide the retention and global stability. Therefore, the Redi-Rock system is a more efficient system for a site like this. In addition, the retaining wall is the most visible part of this development and a good looking retaining wall was necessary for the aesthetics of the development. Redi-Rock provided both strength and beauty in a solution that was ideal for the site."

Despite numerous elevation changes and a global stability issue due to sandy soil, the ease of installing the Redi-Rock system made the project go smoothly.

The project included a 17,250 square foot (1603 sq. meter) retaining wall consisting of 3,400 Redi-Rock wall blocks. There was also a 13.5-foot (4 meter) gravity wall constructed on site, which relies on its mass to resist pressure from behind and has a "batter" setback to improve stability.

This type of wall works well in tight spaces since it can be set vertically. "Redi-Rock was chosen for the project because of our ability to build a strong vertical wall, thus maximizing the usable building space footprint," noted Rick Lindberg, Redi-Rock Design and Sales, Wilbert Precast, Inc.

THE OUTCOME

"The finished product turned out beautiful," added Lindberg. "It accomplished what the owner wanted and came in at budget." The Redi-Rock PC Wall system was an ideal solution for this site since it required a reinforced retaining wall in order to retain the necessary heights, and to provide global stability of the retained soil and wall combination. Additionally, Redi-Rock's Cobblestone face gave the wall an aesthetic quality that blends well with the natural surroundings.

The finished product accomplished the clients' goals beautifully!

"From an engineer's view, the PC connection system is the best system on the market for providing a connection between the geo-grid and the wall blocks. The smooth rounded connection with the grid through the block is the most stable connection on the market with little risk of failure," commented McKervey.

Lindberg added a final note: "As a sales and design professional, I love the Redi-Rock system. It works, it's easy to install, has lots of design options, and the Redi-Rock support team is second to none."

PROJECT DETAILS

Project: Argonne Development Project #193 Manufacturer: Wilbert Precast Inc. Engineer: John McKervey, P.E. Location: Idaho