ROUTE 78 BRIDGE REPLACEMENT
Warwick, Massachusetts


Route 78 (Orange Road) passes through a largely undeveloped area of North-Central Massachusetts. Orcutt Brook exits Wheeler Pond and passes through hilly country before passing under Orange Road at a significant skew angle of 50 degrees. The existing bridge, constructed in 1920, is a cast-in-place concrete arch with earth fill placed between the end walls. Recently the bridge rating was found to be sub-critical because of a combination of both sub-structure and superstructure deterioration.

C&C was engaged to plan for the total replacement of the bridge. Originally, we were requested to consider the use of a pre-engineered, pre-cast box as an alternative to control cost and construction duration. Our investigations revealed that this alternative was impractical because of the need to maintain the radical skew of the crossing. Additionally, the pre-engineered structures required a minimum of one meter of fill over the top of the box, and providing this would have resulted in a significant change in roadway profile. Having eliminated the pre-cast box as a practical alternative and based on the aesthetic qualities of the existing arch-bridge, we recommended replacement with another arch bridge of similar dimensions and design. This alternative will also have the least environmental impacts. We went on to design a cast-in-place reinforced concrete arch, abutment and wingwalls.

Two issues emerged during the design of the bridge that affected the side slope reconstruction and the management of traffic. First, due to the close proximity of bordering vegetated wetlands to the bridge, two different retaining wall systems were designed. One side of the bridge used wire mesh gabions filled with stone and the other side used a dry stone masonry wall. Second, traffic needed to be managed during the construction of the bridge. This was done by a 120 foot pre-engineered temporary bridge and temporary traffic signal to reroute traffic around the bridge during construction. Right-of-way plans were prepared for the temporary bridge easement in accordance with MHD guidelines. Currently, the project was awarded recently with construction anticipated to begin in the fall of 2007.

Client: Massachusetts Highway Department