Lightweight Utilized in Pointe-aux-Chênes Coastal Restoration Project
Key Insights:
Quick Facts:
- Name: Pointe-aux-Chênes Wildlife Management Area Enhancement
- Location: Terrebonne and Lafourche Parishes, Louisiana
- Customer: Delta Coast Consultants LLC
- Client: Louisiana Department of Wildlife and Fisheries
- Size: Six sites, including parking lots and a boat launch
Challenge: Poor subsurface soils (50-60 feet deep) posed a risk of excessive settlement, making traditional backfill materials unsuitable.
How Arcosa Helped
- Our Solution: Arcosa’s lightweight aggregate was chosen to stabilize parking lots, piers, and boat launches, providing a durable foundation in difficult marshland conditions.
- Why Lightweight Works: Lightweight aggregate reduced consolidation pressures, provided a stable foundation, and minimized settlement risks.
Final Results
- The lightweight aggregate has performed exceptionally well and is expected to last up to 50 years.
Key Quote
“It’s holding up really well,” says Jesse Noel, P.E. “It was placed and compacted rapidly with a skid steer and firmed up nicely to accept the stone surface course.”
Context:
- Considerations: Coastal projects benefit from lightweight aggregate due to the material’s ability to perform in weak soil conditions while controlling settlement risks.
- Lesson to Learn: Collaboration between engineers and material suppliers, like Arcosa, is crucial for ensuring project success in challenging geotechnical environments.
Explore Further
Discover how Arcosa’s lightweight aggregate can provide reliable, cost-effective solutions for your next coastal restoration or geotechnical project.
Lightweight Utilized in Pointe-aux-Chênes Coastal Restoration Project
Arcosa’s lightweight aggregate is ideal for addressing the geotechnical challenges of marshland environments, as demonstrated by its use in the completed enhancement of the Pointe-aux-Chênes Wildlife Management Area in coastal Louisiana. The Louisiana Department of Wildlife and Fisheries, tasked with improving the marshland’s productivity, used Arcosa’s lightweight aggregate to mitigate geotechnical challenges posed by the region’s weak subsurface soils. This material was essential in constructing parking lots and rehabilitating boat launches, providing a stable foundation despite the difficult marshland conditions.
The project, spread across Terrebonne and Lafourche parishes, used funds allocated for remediation following the 2010 BP oil spill. Jesse Noel, P.E., a former Project Manager at Delta Coast Consultants, led the enhancement design, which faced the challenge of extremely poor subsurface soils along Island Road. Noel, now a Regional Director at the Southeast Louisiana Flood Protection Authority – West, explained that these soils, extending 50 to 60 feet below the surface, posed a significant risk of excessive settlement.
“We got the geotech report back and there was a lot of concern about the soils,” Noel says. “There was the potential for excessive settlement at some of these sites if we were to load them up with limestone as the backfill material and parking surface.”
Project Overview
The Pointe-aux-Chênes project involved six sites, five of which were parking lots with accessible fishing piers. A vinyl sheet pile bulkhead was constructed at each site, backfilled with Arcosa’s lightweight aggregate. The sixth site included a boat launch rehabilitation, also utilizing lightweight aggregate behind a bulkhead.
Arcosa’s Terry LeJeune collaborated closely with Noel to identify the most suitable products for the project’s needs. After considering several options, they selected a blend of 5/8” and ¼” lightweight aggregate that would offer durable backfill while minimizing consolidation pressures. The choice of lightweight material proved advantageous, particularly in controlling the loads on the sheet pile bulkheads and reducing settlement risks.
Despite working with lightweight aggregate for the first time, Noel had seen its successful application in other coastal projects in South Louisiana. Arcosa’s guidance helped the project achieve the desired balance between durability and ease of installation. Noel reported that the material compacted well and allowed for rapid placement, providing a stable foundation to support the stone surface course.
Final Result
The lightweight aggregate has performed exceptionally well since its placement. “It’s holding up really well,” Noel says. “It was placed and compacted rapidly with a skid steer and firmed up nicely to accept the stone surface course.”
“We have experienced a lot of overtopping on the roadway due to tides and storms,” Noel explains. “That’s another concern and [we will see] how that plays out with some other parts of the roadway, not necessarily our structures.”
He expressed confidence in the material’s continued performance in the face of environmental challenges.
Would Noel use Arcosa Lightweight’s products again? “Absolutely,” he says. “For specific applications, when backfilling bulkheads, I think it’s a pretty good value for what you get.”
