Amendment 0004 - MS ERFO NP VICK 2020-1(2).pdf

(x)

693C7325B000002 x x

1 copies of the amendment; (b) By acknowledging receipt of this amendment on each copy of the offer submitted ; or (c) By separate letter or electronic communication which includes a reference to the solicitation and amendment numbers. FAILURE OF YOUR ACKNOWLEDGEMENT TO BE

RECEIVED AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN REJECTION OF YOUR

OFFER. If by virtue of this amendment you desire to change an offer already submitted , such change may be made by letter or electronic communication, provided each letter or electronic communication makes reference to the solicitation and this amendment, and is received prior to the opening hour and date specified.

x

ASHBURN VA 20147

ATTN: Construction

693C73

SUITE E2-3-300

QUANTUM PARK, 22001 LOUDOUN COUNTY PKWY

EASTERN FEDERAL LANDS HIGHWAY DIVISION

FEDERAL HIGHWAY ADMINISTRATION

ASHBURN VA 20147

ATTN: Acquisitions

693C73

SUITE E2-3-300

QUANTUM PARK, 22001 LOUDOUN COUNTY PKWY

EASTERN FEDERAL LANDS HIGHWAY DIVISION

FEDERAL HIGHWAY ADMINISTRATION

See Block 1412/04/20240004

13. THIS ITEM ONLY APPLIES TO MODIFICATION OF CONTRACTS/ORDERS. IT MODIFIES THE CONTRACT/ORDER NO. AS DESCRIBED IN ITEM 14.

12. ACCOUNTING AND APPROPRIATION DATA (If required) is not extended.is extended, Items 8 and 15, and returning

Offers must acknowledge receipt of this amendment prior to the hour and date specified in the solicitation or as amended , by one of the following methods: (a) By completing

The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offers

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

FACILITY CODE CODE

10B. DATED (SEE ITEM 13)

10A. MODIFICATION OF CONTRACT/ORDER NO.

9B. DATED (SEE ITEM 11)

9A. AMENDMENT OF SOLICITATION NO.

CODE

8. NAME AND ADDRESS OF CONTRACTOR (No., street, county, State and ZIP Code)

7. ADMINISTERED BY (If other than Item 6)CODE 6. ISSUED BY

PAGE OF PAGES

4. REQUISITION/PURCHASE REQ. NO.3. EFFECTIVE DATE2. AMENDMENT/MODIFICATION NO. 5. PROJECT NO. (If applicable)

1. CONTRACT ID CODE

AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT

10/24/2024

CHECK ONE A. THIS CHANGE ORDER IS ISSUED PURSUANT TO: (Specify authority) THE CHANGES SET FORTH IN ITEM 14 ARE MADE IN THE CONTRACT

B. THE ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, C. THIS SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:

D. OTHER (Specify type of modification and authority) appropriation data, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE AUTHORITY OF FAR 43.103(b).

E. IMPORTANT: Contractor is not is required to sign this document and return __________________ copies to the issuing office.

ORDER NO. IN ITEM 10A.

14. DESCRIPTION OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.)

Project MS ERFO NPS VICK 2020-1(2)

The purpose of this Amendment is to:

1) Make a general statement in response to multiple inquiries about pay item B0370

30211-0000 Mechanically Compacted Aggregate Column (Impact (Displacement) Rammed Aggregate

Pier) and associated design work required for this pay item.

2) Respond to bidder questions (including updated responses to Questions "m" and "n" under

Amendment 0001).

Continued ...

16A. NAME AND TITLE OF CONTRACTING OFFICER (Type or print)15A. NAME AND TITLE OF SIGNER (Type or print)

15C. DATE SIGNED 16B. UNITED STATES OF AMERICA 15B. CONTRACTOR/OFFEROR 16C. DATE SIGNED

(Signature of person authorized to sign) (Signature of Contracting Officer)

STANDARD FORM 30 (REV. 11/2016)

Prescribed by GSA FAR (48 CFR) 53.243

Previous edition unusable

Except as provided herein, all terms and conditions of the document referenced in Item 9 A or 10A, as heretofore changed, remains unchanged and in full force and effect .

ITEM NO. SUPPLIES/SERVICES QUANTITY UNIT UNIT PRICE AMOUNT

NAME OF OFFEROR OR CONTRACTOR

2 5

CONTINUATION SHEET

REFERENCE NO. OF DOCUMENT BEING CONTINUED PAGE OF

(A) (B) (C) (D) (E) (F)

693C7325B000002/0004

3) The bid opening date will be rescheduled to

Thursday, December 12, 2024, at 2:00 p.m. EST.

NSN 7540-01-152-8067 OPTIONAL FORM 336 (4-86)

Sponsored by GSA

FAR (48 CFR) 53.110

Amendment 0004

Info Page 1 of 3

U.S. DEPARTMENT OF TRANSPORTATION

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

Amendment No. 0004

Project MS ERFO NPS VICK 2020-1(2)

Vicksburg National Military Park

Solicitation: 693C73-25-B-000002

The purpose of this Amendment is to:

1) Make a general statement in response to multiple inquiries about pay item B0370

30211-0000 Mechanically Compacted Aggregate Column (Impact (Displacement)

Rammed Aggregate Pier) and associated design work required for this pay item.

2) Respond to bidder questions (including updated responses to Questions “m” and “n” under Amendment 0001).

3) The bid opening date will be rescheduled to Thursday, December 12, 2024, at 2:00 p.m. EST.

Solicitation Changes

1) Due to multiple inquiries received for the work required for pay item B0370 30211-0000

Mechanically Compacted Aggregate Column (Impact (Displacement) Rammed Aggregate

Pier), the Government’s explanation is as follows:

Alternative installation methods to rammed aggregate piers will be reviewed after the award and need to comply to the design parameters in the Solicitation.

In accordance with the Special Contract Requirements (SCRs) subsection 302.03A(f) (page J-17), the Contractor is required to submit design computations and design the aggregate columns in accordance with subsection 104.03(b)(2) of FP-14 and based on the information in the

Government’s Geotechnical Report.

The design should satisfy the following parameters:

• A composite friction angle of 32-degrees,

• Minimum Global Factor of Safety of 1.5, under static conditions, and

• Minimum Global Factor of Safety of 1.1, under seismic conditions.

The design for all and any alternatives to rammed aggregate piers will be reviewed by the

Government and either approved or disapproved prior to construction. If the Contractor’s proposed design will require pre-drilling for pier installation, the removal of the soil (currently unaccounted for in the Government’s design) will only be measured and paid under B0370 30211-0000

Mechanically Compacted Aggregate Column (Impact (Displacement) Rammed Aggregate Pier).

Info Page 2 of 3

In addition, Offerors must consider in their bid all costs related to the correction or remediation of any settlements beyond specified tolerances, cave-ins resulting from construction techniques and pre-drilling methods, and constructability challenges stemming from the contractor's chosen methods, equipment, or sequencing. The Contractor will need to haul the waste material offsite and will need to stay within the limits of disturbance currently included in the plans.

2) Responses to Questions:

Revised responses to Questions “m” and “n” under Amendment 0001:

m: Question: Subsection 302.03C(e)(3) states that we can only construct the stone column by utilizing rammed aggregate piers. We request if the use of Casagrande stone column equipment such as what is seen below could be utilized to produce a continuous stone column with quality control methods.

Response: Alternate designs will be considered provided the design meets the design requirements in the J-pages, FP-14 and the Geotechnical Report and all other construction work and materials that would be required for the updated design including replacement of the surrounding loose soil will be a part of pay item B0370 30211-0000 Mechanically Compacted Aggregate Column (Impact

(Displacement) Rammed Aggregate Pier) and will not be measured under any other pay items.

Displacement rammed aggregate piers are considered the most suitable alternative for the subsurface conditions at the site due to the following reasons: 1) In general, the ramming action generates higher lateral stress (less pier deflection) and improves the soil matrix better (high composite friction angle and high soil stiffness). 2) The displacement method eliminates the risk of cave-ins during pre-drilling and pier installation, and 3) No spoils will be produced for off-hauling. However, other alternatives can be considered if they can achieve a composite friction angle of 32-degrees after the improvement, minimum Global Factor of Safety of 1.5, under static conditions, and, minimum Global Factor of Safety of 1.1, under seismic conditions.

n: Question: Specifications state the following:

“302.03C Mechanically Compacted Aggregate Columns Installation.

(e) Column Systems.

(3) Densify each lift using a mandrel/tamper. The mandrel/tamper foot is required to adequately increase the lateral earth pressure in the matrix soil during installation.

Compaction equipment that induces horizontal vibratory energy (such as Vibroflot equipment) is not permitted.

Can you please clarify if any vibratory compaction installation methods are permitted for aggregate pier installation?

Response: See above response to question “m”.

Question: Per specification and RFI response for using any vibratory compaction installation method, can we use down-hole tamper & vibrator methods (Vibratory compaction method)? Using displacement installation method, with being very limited contractors in MS State, it is going to affect the project schedule and cost. Any thoughts on this would be appreciated.

Response: See above response to question “m”.

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Question: The plans and specifications show a 24” constructed diameter Impact Rammed

Aggregate Pier. However, patented Impact tooling only builds a 20” Rammed Aggregate Pier. Are

20” constructed diameter Impact (Displacement) Rammed Aggregate Piers acceptable, as 24” constructed diameter Impact Rammed Aggregate Piers are not constructible with the patented

Impact Rammed Aggregate Pier tooling?

Response: The aggregate pier parameters in the contract documents are preliminary. The

Geotechnical Report (provided as part of the Solicitation), on page 7 (last sentence of the first paragraph), states that the piers “…should be designed and constructed by qualified specialty contractor with a proven record of success in such applications.”. The size and installation methodology of the piers should be selected by the specialty contractor to satisfy the following parameters:

• A composite friction angle of 32-degrees,

• Minimum Global Factor of Safety of 1.5, under static conditions, and

• Minimum Global Factor of Safety of 1.1, under seismic conditions.

Question: Can you advise on the size of the RAP intended?

Response: See above responses about size and installation methodology.

Question: The provided subsurface boring data does not adequately extend to the proposed depth of ground improvement. Our current scope of parameters for the Rammed Aggregate Piers assumes that the soil conditions represented in the subsurface boring data are relatively continuous to the full depth of the Rammed Aggregate Pier. If changes in soil conditions are encountered, the design and cost may need to be revised.

Response: All available subsurface data is included in the Solicitation (Geotechnical Report).