Questions and Answers During Advertisement for AZ FS 24(1) 3-6-2023.pdf

Questions and Answers During Advertisement for AZ FS 24(1) Buffalo Crossing Bridge

Monday, March 6, 2023

Questions Answers

1 Is shotcrete or gunite needed on this project. No, shotcrete or gunite are not needed on this project.

The purpose of this Request for Information is to propose the use of a Modular Steel Panel Bridge furnished by the Acrow Corporation of America (aka Acrow Bridge) as an alternative to the as-designed Modular Steel Girder Bridge structure on the US Department of Transportation FHWA Central Highway Division’s Buffalo Crossing Bridge Project. Attached to this email are example drawings of the proposed Acrow bridge system. The Acrow Panel Bridge would be designed to meet the Live Load requirement of AASHTO HL-93, LRFD, is a prefabricated steel bridge, with galvanized components per ASTM 123, and Acrow Bridge is an AISC Certified Fabricator, all of which are required on Drawing RG3202-B.

No, a Modular Steel Girder Bridge would not be acceptable. Acrow bridges are considered temporary and would not meet the full needs of the project.

The purpose of this Request for Information is to propose the use of a 120-foot span Acrow Panel Bridge in lieu of the 100-foot span shown on Drawing RG3202-A of the Project Drawings of the US Department of Transportation FHWA Central Highway Division’s Buffalo Crossing Bridge Project. The Acrow Panel Bridge cannot be constructed with a skew and would require the additional 20-feet to be properly constructed in a rectangular shape.

No, a 120-foot span Acrow Panel Bridge would not be allowed.

In communicating with multiple modular bridge fabricators, we have only found a single vendor that can meet all of the FHWA project specifications and requirements for this project. Drawing No. RG3202-H (Bridge Drawing 8 of 10) indicates that the galvanized steel decking is to be 9-gage steel, however, several vendors have communicated that they cannot access 9-gage steel decking through their material vendors and are therefore unable to quote this project. Will FHWA approve the use of 18 to 22 gage galvanized steel for the corrugated bridge decking material on this project, which will allow for additional vendor sources to quote the project?

Per the correct final plans, which are currently being substituted, there is no specified gage on the steel decking. That will be determined by the design of the bridge manufacturer.

5 If the HL-93 vehicular loading will be maintained, can we substitute the asphalt driving surface for a 8" concrete driving surface?

The contractor cannot substitute the asphalt driving surface for a 8" concrete driving surface.

6 Regarding Bid Item A0340 Gabions 460 SF: Please clarify the 460 Square Footage Quantity. Gabions are usually bid by the Cubic Yard.

The quantities on the gabions are correct as well as the unit of measure. Please provide a bid per SQFT as listed in the bid schedule. The gabions will be measured by sqft of gabion face, (vertical height x length).

7 Who is the assigned Construction Operations Engineer? Nobody has been assigned yet.

8 Who is the assigned Project Engineer? Nobody has been assigned yet.

9 Does the Government have a water source available for the contractors use? No.

10 What is the anticipated date of Award? ASAP but no anticipated date, see 52.211-10 in Section C of the solicitation (IFB) for the notice to proceed (NTP) date.

11 Is water quality monitoring required? There are no water quality monitoring requirements on this project.

52.211-10 states “… The completion date is based on the assumption that the successful offeror will receive the notice to proceed by 5/1/2023…”. Section 108.01(a) stated “No onsite ground disturbing activities before April 15, 2023”.

These dates conflict, please advise.

No conflict, the April 15th date is if NTP is issued earlier.

Bid Item 25301-2000 Gabions, Polyvinyl Chloride Coated. Please provide the Basis of Payment and Method of Measurement as FP-14 253.10 only discusses cubic yard measurement.

The quantities on the gabions are correct as well as the unit of measure. Please provide a bid per SQFT as listed in the bid schedule. The gabions will be measured by sqft of gabion face, (vertical height x length).

According to the plan Sheet S8 the thrie-beam bridge railing calls for weathering agent coating as well. Do the bridge rail posts require weathering agent, or can this be self-weathering steel?

The bridge rail posts are weathering steel. Just the bridge thrie beam has the weathering agent.

15 The Government completed an Asbestos investigation and provided a report. Did the Government perform a Lead Paint investigation? No.

16 Are there any other locations that the weathering agent is required other than the bridge?

Yes, per Subsection 617.02, treat all galvanized material for guardrail systems with a weathering agent according to Section 563.

17 Can the river be dammed or re-routed to allow access for construction activities?

FHWA does not require a specific method for dewatering. However, methods need to comply with the terms and conditions of the General Permit for Stormwater Discharges, 404 and 401 permits, and the Fish Exclusion and Relocation Plan.

Is it possible to extent the bid date? We have contacted the Alpine Ranger District and were told there is too much snow to access the site. We typically do not bid work without a site visit and good pictures.

The project site has gotten a lot of snow in past few weeks with more projected to fall this week. The Forest Engineer did not think that extending the bid opening by a week or two would allow more reasonable access the site.

So, we will not be extending the bid opening for this project based on weather.

Our roadway aggregate quantity taken off from the plans representing this project is significantly less than the amount shown as the bid quantity for Bid Item A0360 on page A8 of the solicitation. Please confirm the quantity shown for A0360 is correct.

Revised roadway aggregate quantity pending. This will be posted via Solicitation Amendment in SAM.gov.

Our asphalt concrete pavement – type 1 quantity taken off from the plans representing this project is significantly less than the amount shown as the bid quantity for Bid Item A0380 on page A8 of the solicitation. Please confirm the quantity shown for A0380 is correct.

Revised asphalt concrete pavement quantity pending. This will be posted via Solicitation Amendment in SAM.gov.

We raise concerns with the asphalt concrete pavement bridge deck. Plans Sheet S8 shows ACP to be placed on the corrugated metal sheet decking over the steel beams. 1-5/8” of ACP is shown above the crest of the corrugations and 4-3/8” filling the corrugation. Note on Plans Sheet S8 implies the ACP is to be placed in two lifts. Plans Sheet B3 indicates the ACP to follow Specification Section 403 and paid under BI A0380.

Our review of Specification Section 403 lead us to believe that it is intended for ACP on earthen grade, and not for a deck on a steel girder bridge. Our major concerns are as follows:

Placing this ACP on a metal bridge deck.

Compacting this ACP on a metal bridge deck.

Compaction testing this ACP on a metal bridge deck.

Please provide specifications that are applicable to this work.

Our office has successfully constructed several modular steel bridges with structural steel decking and asphalt fill. The bridge fabricator may be able to provide some additional guidance on placing the asphalt on the steel decking.

Plans Sheet S6, in Section A-A, shows the abutment barrel depth to be *5’-0” and the paving notch to be *7”. The asterisk note says, “Final dimensions & elevations to be coordinated with bridge manufacturer prior to ordering materials and constructing abutments.” To us, the asterisk before the abutment barrel depth and the asterisk before the note look identical. The asterisk before the paving notch looks slightly different, possibly font style.

Is the intent for the note to apply to both dimensions?

Yes, the note is intended to apply to both dimensions.

We find no elevation view for the gabion wall, which makes an accurate estimate impossible.

Could an elevation view for the gabion wall be provided?

Per Section 253 of the FP-14 and SCRs, the contractor is responsible for surveying the gabion wall site, designing/laying out the gabion wall, and submitting drawings of the gabion wall to the CO for review and approval.

24 Will the successful contractor be able to have access to the design cad files? Requests for CAD files will be evaluated after contract award.

25 Will the Government add a bid item for Survey and Staking- Pipe Culvert? No bid item will be added for Survey and Staking - Pipe Culvert.

In the project specifications, under the Special Contract Requirements, Section

555. STEEL STRUCTURES, subsection 555.03A General, paragraph (g) of the design criteria on page E-41, it states “Design traffic bridge railing for the design forces specified in Table A13.2-1 for a minimum railing test level of TL-2.” However, on page 2 of 10 of the Bridge Drawings, under General Notes, paragraph 12, line 2, it states “Guardrail shall provide a minimum TL-2 crash test level rating” – this wording is a bit confusing and seems to contradict the rest of the plan set and specifications. Railing for modular steel bridges of this type can certainly be designed to TL-2, but this style of railing has never been formally crash tested.

Please confirm the railing for this bridge need only be designed to a minimum of TL-2 and not crash tested.

The railing shall be designed to provide a minimum test level 2, disregard the word “crash” in General Notes when describing railing test level.

27 The Asphalt Mix Design for the project is unavailable in the area. Are Federal Aviation or MAG Designs Acceptable?

A Type 2 Asphalt Concrete Pavement as specified in Section 403 of the FP-14 and SCRs would be an acceptable alternative. This would allow a local asphalt mix used by Federal or state agencies for the type of work being constructed.

I just want to make sure that it is to be a steel modular bridge that is to accept an asphalt running surface. As for the decking material, 7 and 9 gauge are easily accessible to bridge suppliers. It is also the main used material to give the support that is needed especially on this size of bridge. Do you also have a delivery date of this bridge?

The replacement bridge is a steel modular bridge with asphalt fill. The delivery date of the bridge will need to be coordinated with the prime contractor, to ensure the contract completion date can be met.

29 How does the Government want the Contractor to handle the drilled shaft obstruction in the heel of the Abut footing?

The Government is aware of the conflict between the drilled shaft and the existing abutment. During drilled shaft excavation, a core barrel will be required to drill through the portion of the existing abutment that is in conflict with the drilled shaft.