1. Deconstruct existing bridge a. Save hemlock lumber for re-use (deck boards, railings) b. Dispose of old telephone pole stringers and sills. 2. Re-stabilize banks on either side of the stream with filter fabric and riprap in accordance with the Vermont Standards and Specifications for Erosion Control (pages 39-42). a. Remove existing failed boulder armoring. b. Prepare subgrade. c. Add filter fabric to protect bank and separate subgrade from riprap. d. Place riprap in accordance with the above standards. 3. Rebuild bridge. Basic bridge description is as follows: a. 4 Steel stringers with diaphragms. All members sized appropriately for bike/ped use, snow load dead weight, and occasional use of an emergency UTV weighing maximum 3500 lb. The firm awarded the bid shall submit a letter from a structural engineer providing beam and diaphragm calculations, along with any fabrication details. See Gould Hill Rd. Bridge structural concept plan in Appendix 2: “Gould Hill Rd. Trail Bridge Concept Plan” for basic beam sizing guidelines. b. Sills made of concrete waste blocks or similar, pinned to steel stringers with an elastomeric pad. c. Decking made of 2x6x8’ black locust lumber. Parks can help source this material if needed. d. Railings made of black locust/PT. e. All PT isolated from steel members with Ice & Water shield or similar. f. All fasteners rated for outdoor use. Where fasteners are in contact with PT they should be double galvanized or stainless steel. g. Plans do not need to be stamped, but contractor should include a letter from a structural engineer providing beam and diaphragm calculations. h. Railings on both sides. made with 4x4 PT or Locust, and other locust members. See general bridge specifications in Appendix 3 for additional detail on railings.
