GM2's Bassett Road Bridge over I-91 project, in North Haven, CT was awarded the 2019 ACE Award under the Structural Category. This project is unique because of the combination of challenging elements holistically converging together and resulting in a significant positive impact on the community. To the best of our knowledge, this bridge is the largest 100% Geosynthetic Reinforced Soil – Integrated Bridge System (GRS-IBS) that has been designed and constructed.
Originally developed by the Federal Highway Administration (FHWA), the GRS-IBS system is an innovative bridge technology to help reduce bridge construction time and cost. These projects can be built in weeks instead of months utilizing readily available materials and equipment. The GRS-IBS system uses closely-spaced alternating layers of compacted granular fill material and geosynthetic fabric reinforcement to create a composite soil abutment that works in unison with the superstructure. The final bridge’s unique use of curved geometry for the substructures is the result of thoughtful detailing to ensure an aesthetically pleasing appearance.
The project was a resounding success with lots of positive feedback from the community. Most importantly, the bridge has restored the link that Bassett Road provides over I-91 with a state-of-the-art structure that was economical, aesthetically beautiful and will provide the CTDOT with an asset that will last for a long time with minimal amounts of future maintenance necessary. With significant collaboration with the FHWA, GM2 was able to successfully design and detail a GRS-IBS alternative for this ‘first of its kind’ common abutment geometry. In the process, the design of the bridge pushed the thresholds of a GRS-IBS system and uniquely adapted the technique to be applied to this two-span configuration that could potentially set the precedent for how GRS-IBS bridges are likely to be constructed for this bridge type throughout the region. In fact, the FHWA has reached out to perform a case study evaluation on the lessons learned during design and to assess the in-service condition of the structure.
GM2 as Designer of Record was responsible for Design Coordination and Structural, Roadway, Drainage, and Traffic Engineering.
Responsible Personnel: Jagdeesh Gopal, PE – Project Manager & Lead Engineer (CSCE Member); Sangyul Cho, PhD, PE – Structural Engineer; Luis Vila, PhD, PE – Structural Engineer; Dinesh Kanigolla, PE – Structural Engineer; Yash K. Manandhar – Roadway Engineer; Shraddha Joshi, PE – Traffic Engineer