As part of Upper Mount Bethel Township’s Turnback Program with PennDOT along a section of River Road, the Township recently replaced the bridge culvert structure that carries River Road over an unnamed tributary to the Delaware River. Carroll Engineering Corporation (CEC) performed the surveying, and environmental permitting, with Carroll’s Justin Coyle, P.E., and his design team doing the engineering, hydraulic analysis, project oversite, and other related tasks for the new structure.
The bridge utilized an innovative design concept consisting of a Geosynthetic-Reinforced Soil-Integrated Bridge System (GRS-IBS). The GRS abutments are comprised of compacted layers of coarse aggregate material “reinforced” with woven polypropylene geotextile and faced with a concrete masonry unit (CMU). The integrated superstructure consists of prestressed concrete composite adjacent plank beams and reinforced concrete deck. The GRS system offers a relatively fast, low maintenance, and cost-effective bridge alternative for single-span structures versus traditional reinforced concrete cantilever abutment and footing construction. The project provided improved safety features including standard structure-mounted bridge railing and approach guide rail and roadway reconstruction. The Township also incorporated some low-cost aesthetic features into the project including colored split-face CMU and bluestone capping. Kobalt Construction, Inc. was the contractor while CEC provided construction observation and administration on behalf of the Township. GRS-IBS bridge systems have gained popularity over the last several years after being endorsed by the Federal Highway Administration. “We were excited to apply this innovative new bridge system and application for the Township. The system provides a cost-effective and low-maintenance solution ensuring the bridge’s longevity and we look forward to incorporating this technique on future projects”, said Carroll Engineering’s Justin M. Coyle, P.E., Vice President, and Township Engineer.