Geosynthetically reinforced soil bridge abutments—engineering methodologies pioneered under the auspices of the Federal Highway Administration (FHWA) and prominently featured several times in Geosynthetics magazine—have been built for the first time in the Empire State.
The St. Lawrence (N.Y.) County Highway Department’s use of the innovative bridge-building method has caught the attention of FHWA officials. The county has built five bridges since last fall with foundations of geosynthetic reinforced soils.
Instead of pouring concrete abutments, successive layers of concrete blocks are filled with compacted earth or crushed stone. Geosynthetic fabric is placed between the layers for reinforcement.
The county’s highway superintendent, William E. Dashnaw, said the new construction method speeds bridge building from months to weeks and, furthermore, with a 25–30% lower cost than a traditional bridge.
The attention from the FHWA includes the prospect of using the St. Lawrence County’s sixth GRS bridge project as subject matter for a possible training film. Film footage may be shown at upcoming FHWA meetings in New York, Boston and Atlanta, according to the agency. These meetings may also prompt the creation of a new FHWA technical manual on the building of GRS bridges.