Expanded Bike Trail Benefits from Innovative Use of Lightweight Aggregate
Expanded Bike Trail Benefits from Innovative Use of Lightweight Aggregate
Bike riders in Orland Park, IL, a suburb near Chicago, have an expanded bike trail thanks to Arcosa’s lightweight aggregate, supplied by the company’s Brooklyn, Indiana plant. Orland Park is a growing area committed to improving recreational facilities for its citizens.
A New 1.5-Mile Bike Trail Overcomes Challenging Terrain
A new 1.5-mile bike trail, connecting two existing trails, was constructed through challenging terrain. “The site of the trail is in a swampy, marshy area bordering a large drainage ditch and a pond,” says Jack Moore, Arcosa’s geotechnical market manager. “There was also a steep slope running alongside the trail to contend with.”
“The road parallel to the bike path had been widened roughly a decade ago. Back then, developers found expanded shale lightweight aggregate (LWA) to be the perfect solution for similar challenging site conditions, and as it turns out, lightweight would once again come into play,” says Wolfe.
Two Challenges: Poor Soil and a Steep Slope
A subsurface investigation by the owner’s geotechnical engineer revealed layers of compressible soils just below the existing grade, precisely where the embankment for the newly widened path would need to go.
To address settlement concerns, the geotechnical engineer recommended using lightweight aggregate (LWA) with no more than 70 pounds per cubic foot density. Such a low-density granular fill would reduce applied pressures on the compressible soils. However, the slope still needed to be managed.
“A reinforced slope system, called Tensar Sierra® Slope, was chosen to deal with that challenge,” Moore says. “Arcosa Lightweight was placed in the reinforced fill zone of the Sierra system. Combining our lightweight with Tensar’s system addressed both the poor soil and the steep slope needed to accommodate right-of-way limitations. Using our granular lightweight fill was the best option for the project,” he adds.
Details on Tensar’s Sierra® Slope Retention System
Tensar’s Sierra Slope System is an ideal and economical option when steeper slopes are needed due to right of way limitations or other constraints. The system can significantly reduce material and installation costs by eliminating many limitations imposed by soil conditions and minimizing fill requirements.
The geosynthetic material is layered in with the lightweight fill to provide slope stability. According to Tensar’s design engineer on the project, Vikas Cinnam, Tensar geogrids can be installed as an infill in almost any environment.
“That includes organic soils, saline soils, modified soils, alkaline soils, acidic soils, and soils with transition metals as long as the pH is greater than 3,” says Cinnam. “So, the use of lightweight is one example regarding the flexibility of Tensar systems,” he says.
Working With the Contractor
The contractor, D Construction of Coal City, IL, originally planned to use coarse lightweight aggregate on the project.
But Moore demonstrated that Arcosa’s fine gradation of lightweight aggregate would work equally well and fully meet all the project’s technical specification requirements.
“The slope on the side of the path was pretty steep,” says Chris Piazza of D Construction. “That made the job a challenge, and we had to layer the aggregate with the grid from the Sierra Slope system.”
“Arcosa did a fantastic job of helping us specify the right aggregate and got it there on time,” Piazza says.
Moore highlights that Arcosa Lightweight’s aggregate, with its lower density and higher internal friction angle, is ideally suited for challenging applications.
“In these situations, lightweight aggregate reduces the stress on poor subgrades,” Moore explains. “Its high internal friction angle and lower density also help decrease the lateral earth pressure on the system.”
Additional Case Studies
Modernizing Infrastructure at the Carrollton Water Plant
The Carrollton Water Plant, a critical infrastructure asset for the east bank of Louisiana’s Orleans Parish, supplies around 135 million gallons of treated water daily to homes across New Orleans. Arcosa Lightweight stabilized the land for a new ded…
Read More
Lightweight Aggregate Creates New Land for Cruise Ship Terminal
Port Canaveral, one of the world’s busiest maritime operations, now operates an advanced docking berth capable of handling today’s larger cruise ships. To achieve this, Arcosa provided the lightweight aggregate needed to extend the port into the wat…
Read More
Arcosa Lightweight Aggregate Used to Create Vital Port Space
Arcosa Lightweight is frequently used in expansion projects that create vital port space along the southern tip of Louisiana. The most recent expansion project at Port Fourchon, located in Lafourche Parish, created 300 new acres for development and…
Read More
