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This project, submitted by Geo-Synthetics LLC, won an Outstanding Achievement Award in the 2010 International Achievement Awards(IAA) / Geosynthetics presented by the Industrial Fabrics Association International. Each project in it’s own special way, exhibits outstanding innovation, technical skill and design excellence.
Submissions of geosynthetics projects for the 2011 International Achievement Awards are being accepted now. Submit your projects by July 15, 2011.
Description
This project was Phase 1 of the Taxiway F-North extension at the La Crosse Municipal Airport.
The project goal was to have the taxiway extension fully operational in the fall of 2011. Meeting the timelines of the first phase was critical so the ensuing taxiway construction project could be completed on schedule in 2011.
Location
La Crosse, Wis., U.S.A., is located on the far-western border of the state on the Mississippi River. The La Crosse Municipal Airport is located on French Island in the western part of the city.
The northward extension of Taxiway F was designed to run through a bay in the far-southeastern corner of Lake Onalaska. Placing fill at this site could not be accomplished until sediment up to 4ft deep was removed from the floor of this corner of the bay.
Removal of the sediment using hydraulic dredging was the most cost- and time-efficient method, while handling of the sediment remained a challenge. The engineering and design team chose to use geotextile tubes placed in a lined cell to allow for dewatering of the sediment and return of the effluent to the lake.
Further, the engineering/design team ultimately used five geosynthetic materials to accomplish their client’s goals. Materials and applications used were:
- linear low density polyethylene geomembrane to line the cell to manage effluent.
- geocomposite placed below the geotextile tubes to facilitate dewatering.
- geotextile tubes for dewatering the sediment.
- geogrid to allow for placement of an aggregate layer and sand layer. The geogrid panels were connected with “hog rings” to expedite deployment of the grid under water.
- nonwoven fabric acted as a separator between the aggregate layer and sand layer.
Approximately 16,500yd3 of sediment was dredged and dewatered to allow for placement of 160,000 tons of fill material during a narrow construction window. If the project had not been completed within the proposed timeline, the eventual taxiway completion (fall 2011) would be in jeopardy.
Good engineering and design combined with a team of motivated contractors and suppliers using numerous geosynthetics assured that the 2011 deadline would be met. (Approximately 20 acres of geosynthetic materials were used in this project!)
This project underscored the versatility of geosynthetics as well as the evolvement of the industry. The use of a nonwoven fabric for separation on this project represents one of the most time-proven functions of geotextile materials.
As the fabrics industry grew and diversified durung recent decades, the use of “plastics” for membranes, nets, and grids contributed to the rapid growth of the geosynthetics industry. Often fabrics are used in conjunction with these materials to enhance their performance.
Using variations of the early fabrics for dewatering sediments draws attention to the creativity of the geosynthetics industry to find other end-use applications for materials that are significantly different from their original purpose. An often overlooked benefit of using geotextile tubes to dewater sediment is the fact that this methodology is the most eco-friendly of all options.
This project underscores the creativity of our industry and the confidence of the engineering/design communities in our products across a wide range of applications.