Structures Design - Transportation Innovation
Geo-synthetic Reinforced Soil
Integrated Bridge System (GRS-IBS)
Commonly referred to as GRS Abutments
Informational Photos and Videos
Developmental Design Standard
Usage Restrictions / Parameters
GRS 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 geo-textile or geo-grid. The approach to the bridge is integrated into the GRS abutment in lieu of utilizing an approach slab.
FHWA 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:
FHWA's construction demonstration video is also available on YouTube.
FDOT Design Requirements are provided in Structures Design Bulletin 12-06.
Developmental 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.
Construct GRS abutments and wing walls in accordance with Developmental Specification 549.
With 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.
Use 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.