W_Fk_Foss _Bridge-Install_Plan Set.pdf

1. The work shall be completed before October 31, 2011. The contractor shall post a notice of the work at the trailhead and notify the CO at least 14 days before the planned work dates.

2. The construction crew may camp at the trailhead. They shall not infringe upon or hinder use of neighboring areas by the public, and shall use low impact camping techniques.

3. A helicopter may be used to transport materials to and from the site. The trailhead may be used as a staging area. The helicopter shall not be used on weekends or holidays.

Helicopter use is restricted to between August 6 and October

31. Between August 6 and September 15, flying shall occur between 2 hours after sunrise and 2 hours before sunset. If a helicopter is to be used, a safety plan shall be submitted for approval by the C.O.

4. There shall be no excavation, filling or disposal of material within the wetted perimeter of the stream. Erosion control methods shall be used to prevent silt-laden water from entering the stream. These may include, but are not limited to, straw bales, silt fencing, filter fabric, temporary sediment ponds, check dams of pea gravel-filled burlap bags or other material, and/or mulching of exposed areas. If flooding or weather results in detrimental sedimentation, cease operations until the conditions improve. All disturbed ground shall be reclaimed using appropriate best management practices. Retain measures to prevent sediment from reaching streams until the soil is secure. If appropriate, native species should be used in revegetation.

5. Design Criteria:

Dead Load: Timber at 50 pcf Live Loads: Snow at 200 psf, or 85 psf for pedestrians Deflection: Span length/ 240 for snow load only Max weight of bridge parts shall not exceed 3500 pounds each, as shipped. No field welds shall be required.

6. Materials:

Steel Girders: All structural steel is ASTM A-588 (weathering) plate and structural shapes (provided by the Government prefabricated, including hardware).

Concrete: Class A(AE) 3500 psi. Sills may be cast in place or precast. Submit a mix design for approval and test results (slump, air, and strength) for acceptance.

Timber: All timber is Alaska Yellow Cedar, #2 or better according to WCLIB (provided by the Government, prefabricated including hardware).

7. Construction:

Staking of the structure shall be done by the contractor and approved by the C.O. prior to beginning clearing. Clearing limits are a maximum of 3’ beyond limits of structure. No other vegetation larger than 6” DBH shall be removed without the approval of the C.O. Clearing debris shall be scattered outside the clearing limits. Staking, clearing, excavation, leveling pads, reinforcing steel and rock anchor bolts for footings are an indirect cost to the bridge installation.

The approaches shall be tied into the proposed trail reroute.

Approaches shall be constructed of embankment materials or log crib steps. Contractor shall stake the approach for approval by the C.O. prior to beginning clearing. Clearing, excavation, surfacing (min. 2” of ¾” crushed rock), embankment, and stairs are an indirect cost to the bridge installation.

The contractor shall fall designated hazard trees (estimated 6).

Logs inside the river channel less than 50’ from the bridge shall be bucked into 20’ lengths or smaller to allow them to pass without jamming at the bridge as specified by C.O.