Springfield
VT Route 11, Bridge 61

Springfield BF 0134(49)
Project Location: Town of Springfield in Windsor County on VT Route 11 over Unnamed Brook. The bridge is located approximately 100 ft. west of the intersection with TH-336, Fairgrounds Road, at approximately mile marker 3.742.

This project consists of the replacement of the existing 14’1” wide by 8’9” high corrugated galvanized multi-plate pipe arch. The existing culvert, installed in 1960, is considered to be in serious condition, rated 3, with holes in the invert of the culvert throughout its length. The culvert is 164’ long.

VTrans evaluated alternatives for rehabilitation or replacement of the culvert in an engineering study completed in August, 2017. The study assessed the proposed design criteria for the bridge, Right-of-Way impacts, wildlife impacts, hydraulics, cultural resources, and wetland impacts. Several alternatives were considered including no action, pipe rehabilitation, and pipe replacement. Pipe rehabilitation alternatives included a new pipe liner, spray-on pipe liner, cured-in-place liner, and replacement of the invert with a new concrete invert installed below the elevation of the existing invert to preserve the existing waterway area. Placement of a new pipe by jack and bore was considered. Finally, complete replacement was considered, using a road closure with detour, a temporary bridge, or constructing the new culvert in phases while keeping traffic moving through the work zone.

Given the age of the structure, site constraints, and current conditions, the engineering study recommended replacement of the pipe by installing a new  box whhile maintaining traffic via a detour during a closure period.  There will be one lane closures of the roadway before and after the closure period. The existing roadway meets the geometric provisions of the Vermont State Standards. This is a high crash location, but reconstruction of the roadway is not proposed.

There are a number of challenges associated with this replacement project. First, there is an 8” diameter AC sanitary sewer line that runs directly under the culvert, and is less than 2 ‘ below the culvert. This will have to be relocated prior to the culvert replacement. There are also contaminated soils at and near the outlet end of the culvert. Any contaminated soils excavated will have to be handled as hazardous waste by qualified personnel and disposed of in accordance with regulations. Numerous other aerial utilities will have to be relocated as well.