VT Route 18 over Mad Brook
Vermont Agency of Transportation
- Accelerated Bridge Program: Accelerated Project Design Delivery & Bridge Construction
- Precast Concrete Element Layout & Detailing
- Environmental Coordination
- Aquatic Organism Passage Accommodation Design
- Hydraulic Analysis Coordination
GM2 Associates, Inc. (GM2) was contracted by the Vermont Agency of Transportation (VTrans) for design services for these Accelerated Bridge Program bridge replacement projects. A design schedule was developed in June 2016 and the Contract Submission was submitted in December 2017 with the project advertising in January 2018. The replacement bridges are 16-foot span precast reinforced concrete box culverts with 12-inch high bed retention sills to allow for a natural channel bottom to form, thus accommodating aquatic organism passage. The box culvert replacement design and layout were developed to accommodate construction within a 9-day closure period, after which the road would then be re-opened to traffic. Precast box culvert, footing/cutoff walls, and wingwalls were detailed to promote expedited installation. Construction completed Fall 2018.