Big River Industries Supplies Innovative Product For First-Ever Mechanically Stabilized Earth Retaining Wall
Lightweight Aggregate Paves the Way for a Speedy Completion of the Picardy Avenue Interchange at Interstate 10
Atlanta, GA -- The Picardy Avenue interchange at Interstate 10, one of the most ambitious roadway construction projects ever undertaken by the Louisiana Department of Transportation and Development (LaDOTD) in the City of Baton Rouge, is successfully coming to fruition due to the innovative use of lightweight aggregate produced by Big River Industries. For the first time in its history, the LaDOTD is using a unique lightweight fill in the reinforced zones of the Mechanically Stabilized Earth (MSE) retaining wall, which allows the project to progress without costly ground improvements. Upon completion, the massive retaining wall will cover more than 214,000 square feet, reach heights close to 40 feet and contain more than 120,000 cubic yards of lightweight reinforced backfill.
During the design development phase, Professional Services Industries, Inc. (PSI), the project's geotechnical consultant, discovered low bearing capacity soils in the areas where retaining wall construction was necessary. PSI determined, through analysis of the existing soil conditions, that the critical wall height was approximately 12 feet. This finding meant that retaining walls taller than 12 feet and constructed using normal weight backfill (around 115 pcf) would produce excessive stress on the low bearing capacity soils, which would lead to unacceptable settlements. Since the proposed retaining walls approached heights of 40 feet in some locations, a cost-effective solution needed to be found that addressed these circumstances.
PSI evaluated several options for remedying the problem. One option was to improve the existing foundation soils sufficiently enough to support the new retaining wall. Another was to use lightweight aggregate for fill behind the new retaining wall, which would reduce the structure's vertical pressure on the low bearing capacity soils. PSI determined lightweight fill would be the most efficient and least expensive solution and recommended its use to the LaDOTD's engineering firm, ABMB Engineers, Inc. of Baton Rouge (ABMB). Big River Industries was contacted and provided the design team with the lightweight aggregate information necessary to proceed with the final design. As a result, LaDOTD now possessed a viable option for a cost-effective and timely method of constructing the complex interchange, which included several hundred feet of MSE retaining walls using the lightweight aggregate. The material's low unit weight (around 45 pcf) and high internal stability (phi angle of at least 40 degrees) provided the perfect fill material to use behind the Keystone retaining wall without costly ground improvements. Big River Industries' lightweight aggregate is distinctive because it is manufactured in a rotary kiln that produces ceramic aggregate particles that are filled with air voids – thus producing a strong and durable lightweight material.
"Big River Industries was happy to provide the Louisiana DOTD and the design team with a solution to an ever-growing dilemma of not having the time or money to implement ground improvements. The product's availability, cost and installation capabilities made it a natural, although unfamiliar choice, for the LaDOTD," said Jack Moore, Director of Engineered Applications for Big River Industries. "The lightweight aggregate is the perfect material for weight-critical solutions to many geotechnical challenges where it is necessary to decrease the vertical or lateral earth pressure applied by the fill material."
Big River Industries provided the LaDOTD, the general contractor, James Construction and the retaining wall sub-contractor, ABS Services, Inc. with educational sessions and extensive background information to ensure that everyone involved in handling and placing the lightweight aggregate was knowledgeable about the product and its installation process. Big River Industries will continue to assist the LaDOTD throughout the construction process to maintain their satisfaction and thorough understanding of the product.
The intricate $41 million Picardy Avenue interchange is being developed in six phases and should be completed by late Fall of 2006. The new interchange will add frontage roads, realign existing ramps, widen I-10 and replace the pavement from Bluebonnet Boulevard to Siegen Lane.
Big River Industries, owned by Oldcastle Architectural, Inc., is a leading producer of high quality expanded clay lightweight aggregates and boasts the lightest rotary kiln produced material in North America. Big River Industries serves customers in 26 states with the largest production facilities in the United States featuring seven rotary kilns with an output capacity of more than 1.6 million cubic yards.
Oldcastle Architectural, Inc. is a leading supplier of building materials. The company is comprised of five major product groups including concrete block, pavers, patio blocks, ornamental concrete, brick, packaged cement mixes and roof tile. Located in Atlanta, Oldcastle APG operates as one division of Oldcastle, Inc., the leading producer of aggregates and concrete products in the United States. For more information on Oldcastle APG, visit www.oldcastle.com.
For more information on Big River Industries and its lightweight aggregate, please visit www.bigriverind.com.
Source: Big River Industries