127EAX26Q0013 Precott NF Bridge Insepctions QA2 (002).docx

127EAX26Q0013 Bridge Inspections and Assessment – Prescott NF Q&A #2

1. Can you please provide the coordinates of the structures so that are team can confirm they are proposing on the correct structures??

*Based on satellite image.

2. Also, are there any past inspection reports available for these three that can be shared with the bridge inspection team?

A: For Bridge #9 and Bridge #10, there are available basic sketches and Bridge Inspection (Sep 2011) Summaries. No inspection reports are available for Crooks Canyon. The structures are open to the public and the USFS is not aware of any agency inspecting/maintaining these structures on an ongoing basis.

3. Do we know the approximate construction year for each of these bridges?

A: According to the aforementioned Bridge Inspection Summaries, Bridge #9 and Bridge #10 were built in1955. There are no records indicating the construction year of Crooks Canyon, but the year 1955 would be a safe guess.

4. Do you need plan sketches showing the plan, elevation, and a typical section for each bridge?

A: For all three bridges, detailed drawings showing dimensions of the main load-carrying elements is requested. In addition, a combination of non-destructive and destructive testing (e.g. coring) would have to be employed to map the hidden reinforcement details for all high stress zones (Negative and Positive Moment). As part of the assessment, all bridges should be inspected, in accordance with the latest Specifications for the National Bridge Inventory (SNBI - No. FHWA-HIF-22-017, March 2022 w/ errata#1 03/24) by a Bridge Inspection Team Leader (BITL). The BITL must meet the qualifications specified in the National Bridge Inspection Standards (NBIS, § 650.309 Qualifications of Personnel). Pictures of common features and defects must be included in the inspection report. In addition, an upstream channel profile must be collected, using both horizontal and vertical points of reference. Lastly, recommendations to correct/address defects must be included in the report, with estimated quantities and unit costs.

5. To help us determine the appropriate equipment, could you please provide approximate information about the underside features of the bridges being crossed? For example:

Bridges #9 and #10 – Are these crossing a creek? What is the approximate vertical distance from the bottom of the creek to the underside of the bridge, 7 ft, or 8 ft?

Crooks Canyon Crossing Bridge – Is there a photo Is this crossing a canyon? What is the approximate distance from the bottom of the canyon to the underside of the bridge, 7 ft, or 8 ft?

A: Both Bridge #9 and Bridge #10 cross a creek. The streams are not perennial. The height from the bottom of the slab to the channel bed has not been measured. Pictures shown below indicate that access to the underside might be accomplished via a 10-12’ ladder.

Bridge #9 Elevation

Bridge #10 Elevation

Neither pictures nor measurements are available for the Crooks Canyon Bridge. From satellite images, one can see that the bridge crosses a stream, which does not seem to be perennial. Based on similar slab-type structures around the Forest, the structure is likely to have a low clearance, and a small ladder (6’) might be adequate to reach the underside of the slab.

6. Typically for Federal projects located on or within Federally-owned lands, a state-specific PE license is not required. Please kindly confirm that an Arizona-licensed PE is or is not required for this project.

A: The goal is to obtain a Design Load Rating and a Legal Load Rating. An inspection, in accordance with the SNBI must take place first to determine the condition of each structure. The inspection must be accomplished by a BITL, meeting the National Bridge Inspection Standards (NBIS, § 650.309 Qualifications of Personnel). Once the Bridge Inspections are completed, the information from the inspection can be used to perform the Desing and Legal Load Ratings. The load ratings must be performed under the supervision of a Professional Engineer (PE). The load rating calculation must bear the seal of the PE (any state registration is acceptable). The load rating must be completed in accordance with the latest versions of AASHTO’s Manual for Bridge Evaluation, and AASHTO’s LRFD Bridge Desing Specifications. For the Legal Load Rating, the three Type 3 AASHTO vehicles are to be used.

7. Is there was a page limit associated with the Technical Proposal portion of the submission.

A: There isn’t one listed, but be reasonable with the size of your proposal, based on the complexity of the project.

image1.jpeg image2.jpeg