Q A_03-29.pdf

AK IRR Fort 1002(1) Ivars Road Bridge

# General Technical Question Answer Date

2 x Regarding the referenced project, will the FHWA accept welded wire reinforcements and facing in the integrated bridge system designed in accordance with FHWA‐HRT‐11‐026?

No, welded wired reinforcing and facing will not be acceptable for this structure

3 x

Plan Sheet F2: Section A-A indicates a propsed channel bottom elevation of 985, is the contractor required to re-grade the existing streambed in locations not affected by construction efforts or just limit to the extents of project placed materials (GBS-IBS Materials and Riprap)?

Only regrading of areas affected by construction activities is required, Sheet F.2 shows the proposed streambed elevation that is required when removing the pipe culverts as part of the contract work. The 985 ft elevation is an approximate thalweg elevation at the crossing.

3/10/2016

4 x

Can you please provide flow or velocity data for the Sucker River near the proposed/existing bridge location?

Additional flow velocity is not available: the Sucker River is mainly influenced by backwatering of the Yukon River and is fairly slow moving through most of the year. 3/10/2016

3/2/2016

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1 X Can we propose an alternative bridge design using a steel truss bridge?

This is a site specific design and all design options had been considered, so no alternatives will be allowed.

10/12/2015

# General Technical Question Answer Date

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5 x

Can bridge manufactures propose an alternate deck design to the timber laminated deck if we comply with all other design and Live Load criteria?

Please bid the project as designed with the timber deck (Value Engineering proposals can be proposed after award in accordance with FP‐14 Section 103. 3/16/2016

6 x

The type of "Roadway Aggregate" called out on the plans seems somewhat vague. Please specify type or gradation to adhere to.

Please refer to FP‐14 standard specification, sections 302 and 703.

3/17/2016

7 x

OHW = 991.0'* callout on Sheet G.1 of Project Plans has an asterisk with "Navigational Opening: 7'-0" Min.". How is this OWH level to be interpreted with the 7'- 0" Min Navigational Opening?

the Minimum Navigation Opening is the difference between the OHW elevation and Lower Cords Elevation.

3/17/2016

# General Technical Question Answer Date

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8 x

Alaska state law requires the Ak DOT to inspect all state and municipal owned bridges annually.

It is my understanding that Ak DOT bridge design does not use steel commonly called weathering steel for structural members because it does not lend itself to normal inspection procedures. Has the long term inspection requirements for weathering steel been reviewed for compliance with federal standards for bridge inspection and in particular with bridges over water?

The bridge will be owned by the local tribe in Fort Yukon once the project is complete.

3/29/2016

9 x

Weathering steel is not specifically defined in the contract documents. Is weathering steel to be defined as steel with an atmospheric corrosion resistance index of 6.0 or greater as called for in ASTM Standard G 101?

See next question 3/29/2016

10 x

Which of the structural steels in FP‐14 717.01 would be characterized as weathering steel?

See requirements for structural steel on sheet G.2 (ASTM A709 grade 50W is specified for this bridge), ASTM A709 is an equivalent standard to AASHTO M270

3/29/2016

# General Technical Question Answer Date

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11 x

FP‐14 717.01 provides for HSLA fracture critical members to be AASHTO M270 Gr 50WF or HPS 50WF, among others. Has the long term maintenance requirements of this material installed over water been taken into consideration?

No fracture critical members are detailed or specified on the plans

3/29/2016

12 x

There have been several instances in Alaska of premature failure of structural members made of weathering steel and installed over water, as I am sure you are aware (ASHTO M270 Gr 50WF or ASTM 709 Gr 50WF). Has this been evaluated as to the use of weathering steel on this project?

the guidelines of https://www.fhwa.dot.gov/bridge/t514022.

cfm have been followed.

3/29/2016

13 x

Does WFL have the equipment and expertise necessary to meet the Federal standards for bridge inspections for bridges made with “weathering” steel?

The bridge will be owned by the local tribe in Fort Yukon once the project is complete.

3/29/2016

14 x FP‐14 717.01 references AASHTO M 270.

Where can we review a copy of AASHTO M 270?

AASHTO Publications can be purchased from AASHTO @ https://bookstore.transportation.org/

3/29/2016

15 x

Drawing RG3005‐B calls for laminated timber deck to be treated as per AWPA UC4B. Is pentachlorophenol an acceptable treatment?

Yes, see a helpful guide @ http://www.wwpinstitute.org/documents/L trSize_UseCat_onApr2012.pdf

3/29/2016

# General Technical Question Answer Date

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16 x

Pay Item 30202-2000 is for Roadway Aggregate, Method 2: The pay quantity is measured by the ton. Is this material to be weighed on site or will invoice weights be accepted? Will it be necessary to set up weigh scales on site?

no to invoice weights 3/29/2016

17 x

Sheet E.2 notes stationing for the temporary diversion berm as 105+90 to 106+50 and 107+30 to 107+90. This stationing does not appear to be consistent with roadway centerline stationing nor does it appear to be consistent with the graphics shown on E.2. What is the base line for this stationing as this stationing does not appear to be based upon roadway centerline stationing?

The berm is perpendicular to the roadway 3/29/2016

# General Technical Question Answer Date

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18 x

Sheet E.1 includes a table that indicates the length of each Temporary Diversion Berm is 60 feet for a total length of temporary diversion berms of 120 feet.

Is this to be measured along the Centerline of the berm or the centerline of the road?

centerline of berm 3/29/2016

19 x

Is a diversion berm required for the key trench excavation and the placing of riprap?

Yes 3/29/2016

20 x

Sheet F.2 has a note that labels the east abutment as “spill through abutment”.

Please clarify this note. What is a spill through abutment? What is this in reference to?

A bridge abutment having a fill slope on the streamward side. The term originally referred to the "spill‐through" of fill at an open abutment but is now applied to any abutment having such a slope.

3/29/2016

21 x

Pay Item 25101-0500 is for Riprap, Method A, Class 5: What is Method A?

See 251.07 3/29/2016

22 x

Pay Item 57402-0000 is for Open- Graded Backfill: The pay item is measured by the ton. Does this material have to be weighed?

yes or by ticket 3/29/2016

# General Technical Question Answer Date

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23 x

Is there a difference in Pay Items 20701- 0100 and 20702-0100? If so please clarify.

no, just different uses 3/29/2016

24 x

Contract documents call for Riprap Class

5. There are substantial differences in Class 5 riprap as defined in FP-03 and in FP-14. As these documents appear to have been prepared some time ago, please confirm that the riprap called for is Class 5 per FP-14.

FP‐14 Class 5 3/29/2016