Stone retaining wall plays well in the park

Redi-Rock gravity and reinforced retaining walls
Redi-Rock gravity and reinforced retaining walls

In 2010, construction began on a massive new park system in the Louisville area. One key goal of the project was to link four major parks with a park drive.

Due to the topography of the area, retaining walls have played a key role in creating the Parklands. Designers have chosen Redi-Rock gravity and reinforced retaining walls for multiple phases of the project, allowing them to meet the aesthetic and structural requirements of the project.

This phase of the Parklands project included creating an overpass for I-64, the main corridor between Louisville and Lexington. Completing this overpass project was key in providing access throughout the park system. To keep the stone in place underneath the overpass, the project required a 1,200-sq-ft headwall.

This project hit on two strong points of the retaining-wall system: gravity design and superior aesthetics.

“We went with Redi-Rock because of the footprint that was needed to put the walls in,” explained Burleigh Law, senior project engineer with HNTB Corp. Law was the structural lead for this phase of the Parklands of Floyds Fork project, which also included the development of the bridge concepts, their final design and implementation through construction. “With this system, there were no straps that needed to go in, so we were minimizing the excavation and the backfill that needed to go in there. That was a huge advantage for the wall system.”

The retaining-wall system has the ability to build tall walls without requiring geogrid or tiebacks in many applications. This makes it possible to build close to property lines and existing infrastructure, minimizing excavation and installation costs. Each 41-in. gravity block weighs 2,351 lb, as much as a Budweiser Clydesdale. The blocks utilize a knob and groove technology, which means that the entire retaining-wall structure is interlocked. A local supplier, Redi-Rock of Kentuckiana, supplied blocks for the project.

Aesthetics were also important for the Parklands, since this is a park setting and a popular bike path at the base of the wall.

“One of the main reasons we went with Redi-Rock was because of the Ledgestone series. From an architectural and aesthetic standpoint, it blended well with the park setting,” he said.

The Ledgestone texture features natural stone texture and coloring with 115-sq-ft of nonrepeating texture.

Another unique aspect of this project was another nearby gravity wall for the Louisville Loop portion of the park’s bike path. This portion of the bike path required a switchback, and the Ledgestone wall is located at the outside of the curve. The wall includes gravity retaining-wall blocks topped with freestanding blocks and caps.

“The contractor really complimented the wall system and how easy it was to put in,” Law said. “From a constructability perspective, there were no issues. Ease of installation was key.”

Previous phases of this project included a 41-ft-tall, back-to-back, tiered retaining-wall structure to accommodate the intersection of a roadway and bike path. Another phase utilized the gravity and reinforced retaining-wall systems in the same wall to achieve the height required while keeping costs down.