Prescott_Bridges_SOW_20251120.docx

Prescott National Forest Road Bridge Inspections and Assessments

The Prescott National Forest requires 1) the safety inspection of three bridges in accordance with the March 2022 Specifications for the National Bridge Inventory (SNBI) and all its references and 2) load ratings in accordance with AASHTO’s Manual for Bridge Evaluation (MBE), 3rd ed., 2018.

Work described in this Statement of Work (SOW) shall include all equipment needed to properly assess the bridge condition and collect data to properly perform a load rating. Inspection data, pictures, and recommended work items must be provided to the Forest Service.

Payment will be on a per structure basis, as listed below:

Furnish for approval, a proposed bridge inspection schedule to the Contracting Officer at least 60-day prior to field inspections.

The Contractor shall check with the Forest prior to mobilizing for field work to learn current road conditions, detours, or specific access needs (e.g., reachable only by foot, chainsaw might be helpful due to downed timber, stream levels, etc.).

All work described in this SOW shall be completed within 90 days from the date of notice to proceed.

Technical Requirements

1. Bridge Inspections:

Perform an Initial Bridge Inspection in accordance with the Specifications for the National Bridge Inventory (FHWA FHWA-HIF-22-017). As a minimum, the bridge Inspection report must include 1) dimensions, 2) general and deterioration/deficiencies pictures, 3) the condition of each bridge component, 4) identification of all deterioration and deficiencies, 5) a list of recommended work items with cost estimate of repair, and 6) an Upstream channel cross-section.

Provide, as a minimum, a two-person inspection team with one qualified bridge inspector meeting the requirements of a Bridge Inspection Team Leader (BITL) as outlined in the NBIS (§ 650.309 Qualifications of personnel, ¶ (b)). The BITL must be present during the Field Inspection and sign the Bridge Inspection report. Proof of BITL training must be submitted to the CO.

Deficiencies must be reported with:

a. Measurements (e.g., crack width, spall size/depth, remaining section, etc.)

b. Severity level (inherent, minor, moderate, or major)

c. Level of extent (isolated < 20%, some 20%-50%, and widespread > 50%)

d. Location description (e.g., middle of span 1, mid-height of girder, etc.)

General Pictures – photos taken at each bridge as are follows to illustrate the approaches, bridge profile, channel, deck, abutments/piers and superstructure framing:

1. Approach 1, looking toward the bridge with all topside deck elements visible

2. Approach 2, looking toward the bridge with all topside deck elements visible

3. Bridge deck and railing

4. Underside of structure

5. Upstream, looking downstream at the bridge

6. Downstream, looking upstream at the bridge

7. Looking upstream from the bridge

8. Looking downstream from the bridge

9. Abutment 1 – substructure

10. Abutment 2 – substructure

11. Any Intermediate supports (piers)

12. Special features of the bridge and/or defects – must be labeled

a. Special feature examples: channel protection devices, splices, pin & hanger assemblies, sloppy connection/weldments

2. Hidden Bridge No plans of any kind are available for the structures listed in this SOW. All structures are suspected to consist of reinforced concrete slabs, the reinforcement pattern is hidden and must be determined. A combination of both destructive and non-destructive techniques might be required to determine the location, size, and extent of both positive and negative reinforcement. Submit to the CO the plan and equipment expected to be used to determine the afore-mentioned hidden reinforcement patterns.

3. Load Rating:

Using the bridge inspection data collected and assembled in a report, and the hidden bridge details, perform a Design Load Rating and Legal Load Rating in accordance with AASHTO’s MBE and its references - see publications listed below. The Load rating must be performed by or under the supervision of a registered Professional Engineer.

Report the result of the load ratings along with all assumptions used in the calculations. Attach to the report any calculations or computer output. The load rating must be sealed/signed by a Professional Engineer.

Design Load Rating:

· Load: HL-93

Legal Load Rating:

· Load: AASHTO’s Type 3, Type 3-3, Type 3S2, NRL, SU4, SU5, SU6, SU7, and FHWA’s EV2 and EV3.

· Provide Safe Load Capacity (Ton) or Safe Posting Loads (Ton), as applicable for the vehicles above.

Publications:

· Federal Highway Publication No. FHWA-HIF-22-017, Specifications for the National Bridge Inventory (SNBI), March 2022 (w/ errata#1 03/24) – referenced as the SNBI in this SOW.

· MBE: Manual for Bridge Evaluation (MBE), 3rd Edition (2018) with 2020 interim revision", published by the American Association of State Highway and Transportation Officials.

· LRFD: LRFD Bridge Design Specifications, 9th ed, 2020, published by the American Association of State Highway and Transportation Officials.

Bridge Locations and Reference images

Bridge #9 Located along NFSR 259A at milepost 0.03 (latitude 34.205674, longitude -112.338107), approximately 26.35 miles west of Junction I-17.

Bridge #10 Located along NFSR 9239C at milepost 0.06 from the intersection with NFSR 259A (latitude 34.206532, longitude -112.337959), approximately 26.39 miles west of Junction I-17.

Crooks Canyon Crossing Located along NFSR 52 between 5 Points and Palace Station (latitude 34.385529, longitude -112.413984).

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