Structures Design
Structures Design - Transportation Innovation Geo-synthetic Reinforced Soil Integrated Bridge System (GRS-IBS) Commonly referred to as GRS Abutments |
| Overview Informational Photos and Videos Design Criteria Developmental Design Standard Specifications Implementation Plan Usage Restrictions / Parameters Contact |
OverviewGRS abutments are part of FHWA's Every Day Counts (EDC) initiative to reduce bridge construction time and cost. A limited number of small bridge projects have been constructed in other parts of the country using this technology in combination with precast bridge components. These projects were considered cost effective and are performing well. The lessons learned during those projects led to the FHWA's GRS Guide. Use of GRS abutments and walls on the Interstate or major multi-lane highways requires the approval of the State Structures Design Engineer. GRS abutments are shallow foundations constructed using a combination of gravel and closely spaced layers of geotextile or geo-grid. The approach to the bridge is integrated into the GRS abutment in lieu of utilizing an approach slab. Informational Photos and VideosFHWA produced several videos which provide background information and testimonials from Engineers across the country regarding their use of GRS abutments for bridges on public roads. These videos and several additional construction photos are available at the following FHWA website: https://www.fhwa.dot.gov/everydaycounts/technology/grs_ibs/multimedia.cfm FHWA's construction demonstration video is also available on YouTube. Developmental Design StandardDevelopmental Design Standard D6025 is available for presenting details in the project plans. This Developmental Standard includes details for wrap-around abutments and details for the transition between the roadway guardrail and the bridge railing. Please review the Developmental Design Standards Policy prior to requesting D6025. SpecificationsConstruct GRS abutments and wing walls in accordance with Developmental Specification 549. Implementation PlanWith the exception of Interstate or major multi-lane highway applications, GRS abutments may be utilized, when appropriate and cost effective, on all FDOT projects. Use of GRS abutments on the Interstate or major multi-lane highways requires the approval of the State Structures Design Engineer. Usage Restrictions / ParametersUse of GRS abutments is limited to 1-lane or 2-lane bridges with simply supported end spans of less than 140 feet in length. Abutments are limited to 30 feet in height. The use of GRS abutments on the Interstate or major multi-lane highways requires the approval of the State Structures Design Engineer. Contact InformationSteven Nolan, P.E. |