QnA_11.14.2018.pdf

Questions and Answers during Advertisement for AZ FTNP GLCA 409(2), Lees Ferry Ranch House Access Road

November 19, 2018

Questions Answers 1 Sheet G5, “Contractor Designed Mechanically Stabilized Earth (MSE)

Wall,” Contract Plans, references the use of “Metallic” soil reinforcement. This is the only location in the Contract Plans and Special Contract Requirements (SCR’s) that the use of metallic is referenced. We are requesting that the Hilfiker Retaining Walls standard Welded Wire Wall, utilizing metallic soil reinforcements, in accordance with Section 720.01 (h) “Reinforcing Mesh”, FP‐14, be allowed for the design and construction of the MSE walls, Section 257 “Contractor Designed Retaining Walls,” SCR.

There is no issue with going with metallic reinforcements instead of geogrid. The metallic reinforcement will have to meet MSE design criteria if Hilfiker MSE wall design meets these criteria the wall will be approved for use on the project.

2 Sheets G5 and G6, “Contractor Designed Mechanically Stabilized Earth (MSE) Wall,” Contract Plans, notes 18" (max.) vertical spacing between reinforcement elements. However, the bottom of wall steps shown on the wall elevation, Sheet G1, “Wall Layout,” are in increments of two and four feet, and therefore assumed to be more suitable for 24” lifts. We are requesting that the Hilfiker Retaining Walls standard Welded Wire Wall, with a 24” vertical spacing between soil reinforcement layers be allowed. The Hilfiker 24” lift MSE wall system allows for 2” inches of compressibility at the face and has been supplied on many FHWA projects for over 20 years. Attached are some sample details from previous projects that allowed for 24” lifts.

FHWA CFL has no concerns with the use of 24 inch baskets provided they provide their internal stability design demonstrating that a 24 inch spacing meets the design criteria.

3 Sheet B2, “Miscellaneous Summaries,” Gabion Summary, 48 CY right of station 211+75. However, the location of the gabion spur is not shown on any plan view in the Contract Plans. We are requesting an offset from station 211+75 and/or an approximate location in a plan view.

The CO will determined the location where the spur will be installed at the end of the proposed MSE wall.

4 The Lees Ferry Ranch project calls for an MSE wall design and shows a welded L panel MSE wall Do we have to bid the wall based on the materials shown on the plans?

Or do we bid it a proposal based on our recommendation (example Terramesh wall?

Yes, the contractor bid will be based on the materials shown in the plans. After the contract award is made the contractor may provide a value engineering proposal for consideration.

November 21, 2018

Questions Answers 1 It appears that the specification for the MSE wall will allow a gabion rock faced with wire mesh or precast concrete/masonry unit face, but the specs are written assuming that the rock faced with wire mesh will be utilized and this configuration is also shown on the plans. Will the contractor have the option to select the face treatment or is the intent to use the rock face with wire mesh?

Yes, according to the plan the MSE wall with the rock facing is the is required on this project.

2 The Paria River is listed on Arizona’s 2018 list of impaired waters. Has a 404 permit been obtained? If so, can a copy be provided? What special conditions if any will the project be subject to from the Army Corps or ADEQ due to this designation?

This project is a ERFO repair project of a failed wall from a previous project. The current Wall design places the front of the proposed MSE wall behind the existing Gabion wall. The COR has been notified of the project from the previous repair and the intend of this project is not to build past the previous project limits.

3 Have any borings been completed to show the existing conditions? If a geotechnical report was not completed for this project, can one be provided from the gabion wall project? Are as built drawings from the previous gabion wall project available?

No, borings were completed on the project site. Geotech tech memo is attach.

4 Can Paria River historical flow rates be provided? No, flow rate will not be provided.

5 Will salvaged gabion rock be acceptable for use in MSE wall front facing?

No, the salvaged gabion rock will not be acceptable for use because it doesn’t meet specifications.

6 Section 108. — PROSECUTION AND PROGRESS states “The contract completion date is April 5, 2019.”

The project will require several submittals including the Contractor Furnished Mechanically Stabilized Earth Wall Design which could take several weeks to design, submit, allow for government review, and acceptance. Would the government allow the completion date to be extended?

No, the project will not be extended.

7 The project requires grout to be placed for Item A0200 – Grouted Riprap. Per FP-14 Section 251.06, the air temperature must be at or above 35 °F (1 °C) within the near-surface voids of the riprap and protect it from freezing for at least 7 days after grouting.

The average low temperatures historically do not raise above freezing until the end of February. It was also discovered through discussions with the local Park Service personnel that road conditions can be hazardous due to ice build-up within the heavily shaded areas. These hazard conditions may impact material deliveries. Would the

The contractor should plan accordingly per the plans and specifications in achieving project completion date.

government change the period of performance to March 4, 2019 start date with a 90-day completion window thus better addressing the concerns with meeting the specification requirements for the grouted riprap and alleviating a serious safety concern around performance of the work in January and February?

8 Section 152. — CONSTRUCTION SURVEY AND STAKING states “No horizontal or vertical control information will be provided.” Sheet #A4 shows information control points.

Does the government intend to provide any information as a basis for the project construction staking? Will Autocad files be provided?

Yes, electronic files will be sent to the contractor after the bid is awarded.

9 Section 153. — CONTRACTOR QUALITY CONTROL states “153.02 Qualifications.

(a)(1) Full-time, on-site QCM. Delete subsections (a) and (b) and substitute the following:

(a) Four years of experience managing quality control on highway construction projects of similar type and scope, and (b) National Institute for Certification in Engineering Technologies (NICET) Level III certification, or equivalent, in highway construction or highway material.

(a)(2) Part-time, on-site QCM. Delete the paragraph and substitute the following: Furnish a QCM who has at least two years of experience in highway construction, inspection, quality control, material testing, and (NICET) Level III certification, or equivalent, in highway construction or highway material.

These specifications indicate what is required of a full time on-site QCM and an Alternate QCM but they do not indicate whether a full time on-site QCM is actually required and/or whether an Alternate QCM is required when a full time QCM is not on-site. Please clarify whether or not a full time QCM or an Alternate QCM is required to be on site when work is being performed.

Yes, the QCM is required to be onsite full time. If the QCM is not able to be on site than the Alternative QCM can resume his duties for the short-term period. If the project is working 7 days a week the QCM could ask that the alternate QCM assume his duties for a few days.

10 Can the Paria River be diverted by digging a new channel to the East. No, the Paria River can’t be diverted.

11 Section 153. — CONTRACTOR QUALITY CONTROL states “153.02

Qualifications. (a)(1) Full-time, on-site QCM. Delete subsections (a) and (b) and substitute the following: (a) Four years of experience managing quality control on highway construction projects of similar type and scope, and (b) National Institute for Certification in Engineering Technologies (NICET) Level III certification, or equivalent, in highway construction or highway material.

The Contractor should bid Section 153 per the project specification.

(a)(2) Part-time, on-site QCM. Delete the paragraph and substitute the following: Furnish a QCM who has at least two years of experience in highway construction, inspection, quality control, material testing, and (NICET) Level III certification, or equivalent, in highway construction or highway material.

These specifications indicate that a NICET Level III or equivalent, is required for the QCM and Alternate QCM but since NICET Level III is not necessarily the only or most current certification standard available what are the acceptable equivalent certifications for the QCM and/or Alternate QCM?

12 Is there an approved excess material disposal area with vicinity of Lee’s Ferry?

All the material that is not incorporated into the project will be removed from the site and will be hauled offsite. No disposal site is available within the Park or vicinity of Lee’s Ferry.

13 Sheet G-2 shows the NE corner of the proposed grouted riprap section at Sta. 211+86 to be South of the existing bank wall. This design could cause future eroding and failure of the existing slope and under mining of the North wall of the newly installed grouted riprap. In order to address this obvious concern in a contractor provided wall design we need to know if the intent is to close off this area to future potential erosion with the new wall and grouted riprap or not. If that is not the intent of this project to close off this area of future scour and erosion at high water levels then it may be difficult to get an engineer stamped design for the wall. If it is the intent to address this issue in our proposed design we will need to know how the potential increases or decreases in pay quantities will be addressed under the contract if the bid schedule does not address these potential quantity changes.

Please clarify how the bidders are to address this issue as it relates to our proposed wall design and the required grouted riprap quantities as well as other potentially affected pay items.

Contractor should bid the project according to the Plan and Specifications provided.

14 What/where are the construction limits? They are not shown on the drawings or called out in the documents.

The construction limits are limited to the Lee Ferry roadway up to the gate of the ranch house.

15 What/where are the identified staging areas? They are not shown on the drawings or called out in the documents.

The Contractor is to stage on the Lee’s Ferry road. No additional staging areas are provided.