Attachment 1 Government Questions to Industry.pdf

Fort Worth Central City (FWCC) Bypass Channel South (BCS) Request for Information to Industry RFI-0001

Attachment 1- Industry Questions Background for Questions 1-2: The South Bypass channel is anticipated to require the importing of borrow materials from a prior construction project called the North Bypass channel on the opposite side of the Trinity River. Reference Sheet GC004 in Attachment 2. The materials to be imported include riprap (estimated 70,000 CY) to be processed from raw rock excavated during the North Channel project and consisting of D50 material in the 15-18” range and select common fill (Estimated 115,000 CY). The select common fill is anticipated to be crushed stone that will also be processed during the North channel contract from rock excavated onsite. The material stockpiles are anticipated to be near the intersection of Throckmorton Street and NE 6th Street. The default hauling method is to use on-road dump trucks, which will require an approximately 5.6-mile round trip (2.8-mile each way).

1. The Government would like to know if, based on the material types and estimated quantities, there are other feasible means to move the material that would be cost-effective and preclude the need for a significant number of on-road trips. Advise on the feasibility of the following:

a. Use of a conveyor system, to be designed by the Contractor, to go over the existing levees and crossing over the West Fork Trinity River. Estimated conveyor length 1,600 feet.

b. Use of off-road haul trucks which would require temporary earthen ramps over the existing levees and a temporary bridge, to be designed by the Contractor, over the West

Fork Trinity River. Estimated bridge length 260 feet.

c. Are there any other hauling alternatives that should be considered? If yes, please describe.

2. The answers to the questions above will assist the Government in defining specification and submittal requirements for the Contractor for potential alternatives. It would be anticipated that if any of these alternatives are allowed, additional design would be as a delegated design component to maximize the flexibility and innovation of the contractor. Based on a delegated design component requirement, please advise on the following:

a. Provide a list of any specific design requirements that would be desirable to be provided by the Government

b. Provide a list of any limitations that would preclude the feasibility of the alternatives.

c. Provide any other lessons learned or other inputs that may be beneficial for consideration to the hauling operation.

Background for Question 3-10: South Bypass Channel includes large retaining walls on one side of the channel for approximately 3800 linear feet or more of the channel alignment. The retaining walls are currently designed to be supported on a foundation consisting of deep mixing method (DMM) (i.e., deep soil mixing), panels that are 6 feet wide and spaced 20 feet on center. Within the DMM panels are 2 or 3 wet sticked steel pipe piles. The following are the general site conditions.

a. Soil Conditions:

i. CL/CH 25-35 feet thick, underlain by

ii. SM/SW/SP/GP/GW 5-20 feet thick, underlain by

iii. Limestone/Shale (40-50 feet below grade)

b. Groundwater

i. 10 to 15 feet below grade

c. Consistency

i. CL/CH: medium stiff to hard

Attachment 1- Industry Questions

ii. SM/SW/SP/GP/GW: loose to dense

iii. Limestone/Shale: A couple inches to a couple feet of weathered over competent, unweathered rock

d. Strength

i. CL/CH: Su = 1000 psf to 4000 psf above the GWT, 750 psf below the GWT

ii. SM/SW/SP/GP/GW: Friction angle = 29 deg

iii. Shale: 40 tsf

iv. Limestone: 250 tsf

3. What’s a rough order of magnitude (ROM) cost range (per cubic yard) for DMM 6 foot wide shear panels through 30 ft of medium stiff clay and 10 ft of medium dense to dense sand and gravel (40 foot total depth)?

4. For DMM in a medium stiff clay, can a mix strength UCS of 150 psi be readily achieved, and what is a typical cement percentage by weight to achieve this? What are typical spoils percentages for deep soil mixing in these materials for a 150 psi strength?

5. What typical SPT N-value for sand and gravels would significantly slow production and constructability of shear panels?

6. For the channel 6 ft wide x 82 ft long shear panels approximately 40 feet deep are planned.

a. Based on typical production equipment, what would an estimated number of panels per day per crew?

b. Given the overall size of the site, would multiple crews by used? If yes, advise on the estimated number of separate crews.

c. Based on typical production equipment, what is the minimum overhead clearance and swing radius needed for DMM?

7. What type of mix strengths are achievable for jet grouting where overhead clearance is not adequate?

8. Are there issues with excavating cured shear panels for lower wall foundation construction?

9. Would a laboratory bench scale treatability study be beneficial data for bidding, or is it preferred that this work be conducted by the contractor during construction? Would it be worthwhile to provide representative soil samples to contractors during bidding to design their mix design?

10. Installation of the pipe piles in DMM

a. What types of issues would arise for installing pipe piles in “wet” shear panels and driving to bedrock?

b. What is your project experience with “wet-stick” structural elements in DMM shear panels for permanent design?

c. What concerns would you have with the proposed wet-stick design, and how would you recommend the design mitigate the risks?

Attachment 1- Industry Questions

11. Since project’s floodwalls are founded on deep foundations and deep soil mixed panels, provide recommendations for construction phasing and sequencing for the floodwall’s foundations, DMM panels, sheetpiles.

12. The contractor will likely have to perform mass concrete pours, some being during very hot

Texas summer months. Aside from performing night pours and concrete mix design modifications, provide recommendations on how to mitigate contractor schedule, cost, and quality risks due to mass concrete pours for the proposed floodwall design.

13. Please provide any specific types of material, sources of labor, or other areas of cost that are considered high-risk for pricing in firm-fixed price proposals as the result of any tariffs announced by Executive Orders 14193 and 14194 and any amendments.

14. Does your company advocate the use of FAR 52.216-4, Economic Price Adjustment-Labor and

Material, to mitigate risk? If not, please provide any recommendations on other methods the

Government could use in reducing pricing risk.

15. If the Economic Price Adjustment (EPA) clause were included in a contract, would FAR 16.203(c) or (d) be the preferred method for determining price adjustments? The standard limitation on

EPA clauses is 10%. Do you believe this is adequate? If not, please provide a reasonable limitation for any of the materials, sources of labor, or other areas of cost identified in response to Question 12.

16. Do you have any recommendations on the structure of the requirements or the overall contracting strategy that would potentially reduce pricing risk (financing, payments, etc.)? Please provide information about methods that have been successful and not successful to assist in creating potential best practices.

17. Do you have any other comments about these features or recommendations on things to consider?