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During the Geo-Frontiers 2011 event in Dallas, the International Association of Geosynthetic Installers (IAGI) announced the winners of the association’s installation awards of excellence. The highest vote getter in this year’s competition and Award of Excellence winner was CETCO Contracting for its exemplary work on the Pennsylvania Department of Transportation’s (PADOT) I-99 slope remediation construction. That project is summarized here. – Chris Kelsey, Editor, Geosynthetica
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PROJECT: PADOT I-99 — Design-Build Slope Remediation
LOCATION: Centre County, PA
PRODUCT: Bentomat®
CETCO Contracting Serivces provided original concept design through final design, permit assistance, construction drawings, material supply, installation and consulting services for protection of immovable material.
The I-99 project has involved the construction of a four-lane limited access highway with four interchanges and approximately 18 miles of roadway.
During construction, large volumes of pyrite-bearing sandstone were exposed to air and precipitation, creating the potential for acidic runoff containing elevated concentrations of heavy metals and sulfates. The runoff from these areas threatened the quality of two adjacent exceptional value trout streams and local residential water wells.
Challenges
PADOT requested turnkey design through installation solutions for the protection of immovable materials. The slopes to be protected varied from 2:1 to 1:1 and were from 100 feet to 350 feet in length. The design had to meet the requirements of both PADOT and the state Department of Environmental Protection (PADEP).
Solution
The final design consisted of a 40-mil textured geomembrane sandwiched between two 16 oz/sy nonwoven geotextiles. Due to the steepness of all slopes, a geocellular system was used to support all cover soils placed over the impermeable liner system. The geocells were supported with stainless steel cables tied into an upgradient, perimeter anchor trench which eliminated the need for penetrations in the liner.
CETCO Contracting Services Company is focused on the design, supply, and installation of geosynthetic and geotechnical construction materials for civil, environmental, remediation, hydraulic, and transportation projects. For more information on CETCO Contracting’s work and geosynthetics, visit www.cetco.com/CCS.
