The City of Stamford expects to issue bid documents for the subject project in mid-late September 2019 with an anticipated award date in November 2019. Below is a description of the existing bridge structure and proposed project improvements.
The Main Street Bridge was originally constructed in 1883 and is approximately 125 feet long, 34 feet wide with 6-foot wide sidewalks on each side. The original 2-span structure consisted of steel lenticular pony trusses supporting a steel floor beam-stringer framing system. The surface consists of a reinforced concrete deck overlaid with bituminous concrete. The substructure consists of abutments and a central pier constructed of mortared stone masonry and concrete. Concrete mini piers were added after the original bridge was constructed to support trolley service in the early 1900’s. Timber sidewalks are supported by timber stringers that bear on cantilevered floor beam ends. The bridge also supports several utilities including gas, telephone and electric. The existing bridge was listed on the National Register of Historic Places on May 21, 1987 and has been inventoried as part of Connecticut’s Historic American Engineering Record as possessing historic and engineering significance. The bridge is currently closed to vehicular traffic but is open to pedestrians.
The proposed project will consist of a limited rehabilitation of the existing bridge in place, while still providing a safe and aesthetically improved structure for pedestrian walkway use as well as small emergency vehicles when complete. In general the repairs will include:
- Replacing and repointing portions of the failed existing stone masonry at the western abutment and central pier
- Minor patching of the spalled areas of mini piers
- Installation of rip rap scour protection
- Removing exterior portions of the floor beams and repairing the portions that are to remain
- Repairing, rehabilitating and painting the existing trusses
- Installing reinforced concrete bridge deck
- Installing utility supports/hangers
- Installing fencing, lighting and landscaping beds
As part of the project, a temporary bridge will be installed north of the existing bridge to allow closure of the bridge during construction. Water handling will be accomplished through the use of cofferdams and all required permits will be in place prior to the start of construction.