SOW_Mike Harris_Final.pdf

Mike Harris Bridge Replacement Statement of Work

The Mike Harris Bridge over trail creek is a single lane timber structure installed in the 1960s. Since that time, visitation to the Mike Harris Trailhead and Campground has increased significantly. Due to the age of the bridge and the increased use, replacing the bridge will be a significant benefit to the public. The Teton Basin Ranger District has secured funding to replace the bridge with a new structure that will meet current and future needs.

The old bridge will be removed and disposed of. The stream channel will be reconstructed with riprap installed to protect the substructure of the new bridge while maintaining and restoring the natural stream channel and surrounding riparian area.

There is an electrical utility line attached to the existing bridge that will need to be removed, protected, and reinstalled on the new bridge. Its underground location is not known.

The new bridge will be a prefabricated steel bridge placed on precast concrete grade beams. The bridge design shall be performed by the contractor to fit the envelope shown on the Forest Service drawings. Design calculations and shop drawings shall be submitted to the Forest Service for approval 2 weeks prior to fabrication.

The approach between Highway 33 and the bridge shall be widened to accommodate 3 lanes of traffic; one lane to exit the highway and enter the Mike Harris Trailhead, a left turn lane to enter the highway northbound and a right turn lane to enter the highway southbound.

The base bid includes aggregate approaches and an aggregate wearing surface on the bridge deck. Option A deletes some of the aggregate approach surface and the aggregate deck wearing surface and replaces them with asphalt surfaces. Option B increases the length of the asphalt surface.

Preliminary work may begin immediately after the contract is awarded but work on the ground cannot begin until September 3, 2024. The road and bridge closure may occur on or after September 4th, 2024. The road closure and existing bridge removal shall not take place until the contractor has a confirmed delivery date for the new bridge.

Periods of delay that extend the duration of road closure shall be minimized; the contractor should not close the road and existing bridge unless on-site work to install the new bridge will continue.

Snow may begin to accumulate in mid-October. If weather prevents completion of the project during the fall of 2024 work shall not be paused until the bridge is installed, and approaches constructed so that bridge may be reopened for public access to Mike Harris during the winter season.

The Forest Service will obtain the necessary permits for the work below the Ordinary High-Water Mark. All conditions of the permits shall be complied with. The instream work window is September 15 to May 15. All work below the high-water mark must occur within that period unless a waiver is approved to allow instream work outside of that period.

See the Schedule of Items, the Forest Service drawings, FP-14, and the Forest Service Supplemental Specifications for all the details of this project.

All materials, construction, and workmanship shall be in accordance with Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects, FP-14 U.S. Customary Units and Applicable Forest Service Supplemental Specifications.

Figure 2 Looking across the Bridge towards Highway 33.

Figure 1: Looking across the bridge into Mike Harris Trailhead.

Figure 3 Underside of bridge and one abutment.

Figure 4 Electrical Utility Attached to Bridge.