Bid - Runway 4-22 Extension Project Construction Runway 4-22 Extension Project Construction OCA-25-0173vnd.openxmlformats-officedocument.wordprocessingml.document

SOLICITATION FOR SOIL

Overview:

The City of Tuscaloosa is undertaking a federally funded project to extend the Tuscaloosa National Airport’s primary runway. A future bid advertisement for the project is expected to be announced within the next 120 days.

Landowners who have potentially suitable material that can be excavated from their land are encouraged to reach out to general contractors properly licensed to perform work on airfields (Alabama General Contractor’s license with H-RR designation). The intent of this notice is to provide additional time for landowners to conduct a geotechnical investigation as a required element of the General Contractor’s submitted bid. Such costs associated with these geotechnical efforts are reimbursable only through any agreement made with the General Contractor and not directly with the City of Tuscaloosa.

Questions may be submitted in reference to this solicitation immediately upon this notice and through the specified deadline for questions referenced in the subsequent bid advertisement. At the option of the landowner, results of the geotechnical investigation may be submitted for review, but no later than with the General Contractor’s bid submittal.

The contact for this solicitation is:

Airport Director

7601 Robert Cardinal Airport Road, Tuscaloosa, AL 35401

jrpowell@tuscaloosa.com

This project will require the embankment of approximately 900,000 cubic yards of imported fill material for the construction of an extension to Runway 4-22 to the southwest. Landowners who have potentially suitable material that can be excavated from their land are encouraged to reach out to general contractors properly licensed to perform work on airfields (Alabama General Contractor’s license with H-RR designation).

Material to be supplied for runway, taxiway, and runway safety area embankments will need to be demonstrated to meet certain physical requirements typical of the embankment of structural fills for heavy-duty pavements. Demonstration of the material’s suitability will be required in the form of a geotechnical investigation supplied along with a contractor’s bid on the project.

Details concerning minimum physical properties of the soils and approximate embanked volumes of soil materials comprising various portions of the embankment are provided below, along with the minimum required frequency and degree of sampling and testing needed to demonstrate that the material meets these properties.

Minimum Physical Properties:

Please see Figure 1, a schematic drawing representing the fill placement on the project site entitled “Embankment Utilization Typical Section,” provided at the end of this narrative. The following general notes and symbol definitions apply to the figure:

GENERAL NOTES:

1. Runway and taxiway width dimensions are representative, along with typical surface slopes noted in units of “feet per foot,” and embankment slopes and control line slopes listed in ratios of horizontal run to vertical fall. Subgrade dimensions and control lines are standard. The details shown on the Figure 1 “Embankment Utilization Typical Section” do not supersede the details that will be included in the fully developed project bid Plans when they are issued.

2. Plastic (P) soils may be placed above the existing water level (at the time of construction) to within 24 inches of the proposed pavement base. It should be placed uniformly in the lower portion of the embankment for some distance along the project rather than full depth for short distances.

3. High Plastic (H) soils excavated within the project limits may be used in embankment construction as indicated on the Figure 1 “Embankment Utilization Typical Section.” High Plastic soils are not to be used for embankment construction when obtained from outside the project limits.

4. Select (S) soils having an average organic content of more than two and one-half (2.5) percent, or having an individual test value which exceeds four (4) percent, are not permitted in the subgrade portion of the roadbed. Select (S), Plastic (P), or High Plastic (H) soils having an average organic content of more than five (5) percent, or an organic content individual test result which exceeds seven (7) percent, are not permitted in the portion of embankment inside the control line, unless written authorization is provided by the Engineer; these soils may be used for embankment construction outside the control line, provided they can be compacted sufficiently to pass a proof roll by a loaded dump truck with 80 psi tire pressure. Determine average organic content from the test results from a minimum of three randomly selected samples from each stratum or stockpile of a particular material. Perform tests in accordance with AASHTO T 267 on the portion of a sample passing the No. 4 sieve.

5. Highly organic soils, composed primarily of partially decayed organic matter, often dark brown or black in color with an odor of decay, and sometimes fibrous, are designated as muck. Further, any stratum or stockpile of soil which contains pockets of highly organic material may be designated as Muck (M). Highly organic soils are not permitted within the subgrade or embankment portion of the roadbed.

Classifications are listed left to right in order of preference.

* Certain types of A-2-4 material are likely to retain excess moisture and may be difficult to dry and compact. They should be used in the embankment above any water level that may be existing at the time of construction. They may be used in the subgrade portion of the roadbed when approved by the Engineer. A-2-4 material placed below the existing water level must be nonplastic and contain less than 15% passing the No. 200 U.S. Standard sieve.

• Approximately 270,000 cubic yards of Select (S) materials, as defined in the Figure 1 “Embankment Utilization Typical Section” will be required

• Up to approximately 160,000 cubic yards of High Plastic (H) materials, as defined in the Figure 1 “Embankment Utilization Typical Section” will be allowable in designated areas on the outer embankment slopes

• The remaining roughly 470,000 cubic yards of embankment material may be of Select (S) or Plastic (P) designation, in designated areas as defined in the Figure 1 “Embankment Utilization Typical Section.”

Minimum Geotechnical Testing Requirements:

The following guidelines shall be used for a geotechnical investigation demonstrating the characteristics of the borrow materials to be supplied for embankment. Suppliers of borrow materials must be prepared to provide the results of the geotechnical investigation at the time that project bid documents are due.

• The investigation shall be sealed by a licensed engineer in the State of Alabama.

• A map of the boring locations overlaid on aerial imagery shall be provided.

• Borings for subsurface exploration shall be no farther apart than a 300-ft grid spacing

• Borings shall be advanced to suitable depth to identify the depth to which excavation of the borrowed materials will be excavated.

• Grid coverage area and depth shall represent, at minimum, a volume of material equal to the required borrow volume of approximately 900,000 cubic yards.

• Standard Penetration Test (SPT) data taken at a minimum of 2.5-ft intervals and presented in a boring log for each boring showing blow counts and N-values alongside moisture content.

• Boring logs shall note the presence of any groundwater encountered. If groundwater is encountered in a boring that boring shall be left open and groundwater level checked after 24 hours.

• For each distinct soil type encountered in each boring, the Unified Soil Classification System (USCS) designation shall be listed.

• For each distinct soil type encountered in each boring, Atterberg limits tests shall be performed on bulk samples and the Plastic Limit and Liquid Limit shall be listed.

• For each distinct soil type encountered in each boring, Sieve Analysis shall be performed, noting the percent of material passing the No. 10, No. 40, and No. 200 sieves

• For each distinct soil type encountered in each boring, AASHTO Classification of the soil shall be noted on the boring logs.

Figure 1 Embankment Utilization Typical Section