Tununak Airport Rehabilitation Drilling Services

Contract#: CFAPT00854-A Federal# / IRIS Program#: AIP 3-02-0486-003-2024 / CFAPT00854-A Region: Central Region This federally funded contract will perform drilling in Tununak, Alaska beginning approximately October 10, 2022. This drilling is in support of gathering geotechnical design data. Approximately 34 test holes from 15 to 40 feet in depth and 24 test holes to 3 feet in depth are planned. Field work will be supervised by a DOT&PF engineering geologist. On the Job Trainees/Apprentices (item 645): None Engineer's Estimate Range: Between $200,000 and $500,000 AKDOT - Tununak Airport Rehabilitation Drilling Services *The value for this project is based on a financial range. The value is listed as the highest possible cost from the range provided by a stakeholder or official project document. Description of Work The Alaska Department of Transportation and Public Facilities (DOT&PF), Central Region Materials (CRM) Section requests bids to perform drilling services for the above-mentioned project in Tununak, Alaska. This work is in support of gathering design data. o A total of 34 test holes from 15 to 40 feet deep are planned. o See the Proposed Test Hole Location Map (2 pages) (attached). o A total of 24 test holes to 3 feet deep are planned. o These shallow test holes are not shown on the map. They are located on the runway, taxiway, and apron embankment. The CRM Engineering Geologist will provide locations for these shallow test holes when on site. o Field work will be supervised by a DOT&PF Engineering Geologist who may modify the number of test holes drilled, depth drilled, and location. o DOT&PF will obtain any necessary permits and perform the utility locates. o DOT&PF will coordinate any FAA NOTAMs required for drilling on the runway. Proposed Drilling: 1. Shallow Airport Embankment Test Holes a. 24 shallow test holes drilled by hollow stem auger from two to three feet deep. b. These test holes will be drilled with hollow stem auger and the auger spin up will be sampled. c. These are to define the thickness of the runway, taxiway, and apron gravel surface and underlying subbase material with cobbles. 2. Deep Airport and Access Road Test Holes a. 30 test holes drilled though the airport and access road embankments and at least 4 test holes located off the embankment on unimproved ground next to the taxiway and runway embankment. These will range from 15 to 40 feet deep and will encounter rocky hard drilling within the embankment and will probably encounter variable conditions beneath and adjacent to the embankment (ranging from soft soil that was previously frozen to hard intact permafrost). b. Test holes will be drilled initially with hollow stem auger and sampled with a split spoon. Alternate methods described in the Drilling Equipment and Supplies section shall be utilized if necessary to achieve the planned depth. c. Sample intervals will be from surface and every 2.5 feet to ten feet below ground surface (bgs) and then every five feet to bottom of test hole d. The number of test holes may be increased or decreased depending on field data. Offembankment test holes may be added. Surface and Subsurface Drilling Conditions 1. The soil types are expected to be variable across the site: a. On Runway, Taxiway, and Apron: o One to two feet of granular surface material, over o One to two feet of crushed rock with cobbles, over o Five to twenty-five feet of silty poor quality rock embankment, over o Organic or silty soil that may be either saturated or frozen. Drilling Equipment and Supplies: 1. General a. Provide a track-mounted drill rig capable of drilling test holes to 40 feet using hollow stem auger (HSA) and direct push methods and collecting macro core samples. b. Provide all necessary labor, material and equipment to drill test holes using hollow stem auger or direct push macro core to at least 45 feet (five more feet of tooling than the planned 40 foot depth). c. Rock embankment is expected beneath the granular surface course at the airport and access road. Provide an air rotary and driven casing system AND (as a backup) a down-hole hammer system to drill to 40 feet in case HSA isn't able to penetrate the rocky embankment. Provide an air compressor with 185 CFM and 130 PSI capability to accomplish the work. d. Winching the rig up or down the embankment slope to reach proposed test holes will be necessary to access some of the drill sites. The drill rig shall be fitted with a heavy duty winch rated for the weight of the fully loaded drill rig used on this project. Provide all equipment necessary to winch the rig upon arrival to the site. Provide six four-foot by eight-foot geo-mats to be used when the tracked rig is drilling at the toe of the embankment or on tundra (with surface water possible). Also provide at least four six-inch by six-inch by six-foot long timbers. e. Provide the necessary equipment and split spoon samplers (at least two samplers) to conduct Standard Penetration Tests (SPT) using a 1.4-inch I.D. x two-inch O.D. split spoon sampler driven by a 140-pound automatic hammer. This includes a minimum of two new or unused split barrel samplers, 10 extra plastic sample retainers, and five extra drive shoes. f. Provide a minimum of 200 5-foot plastic sleeves for macro core sampling. g. Provide a generator and light stand with two LED lamps (144 W, 13,200 Lumens) to illuminate the work area when working at night. Also provide an orange strobe light (120V AC, 90 flashes per minute) to be placed on the drill rig mast. h. The Contractor shall be responsible for proper compaction of cuttings placed back into the boring. Such as back-spinning augers while placing cuttings back into the boring (no peat or wet soil will be used as backfill of the borings). The Contractor shall use a six-inch diameter steel plate attached to drill rods to compact the soils in the boring. Compaction shall be accomplished by driving the drill rods (with an anvil attachment) using the 140-pound automatic hammer to ensure the soils in the bore hole are well compacted. i. The Contractor shall have on-site a spill kit consisting of a 35-gallon drum that contains (at a minimum) two Tyvek Suits with plastic gloves and boot covers, five 45-gallon heavy duty trash bags, ten feet of oil sorbent boom, 100 oil absorbent pads (two feet square, high absorbency), and a five-gallon bucket of oil absorbent material. j. The automatic hammer shall already be mounted to the drill mast and ready to deploy when the rig is moved to the first test hole site. No automatic hammer will be accepted that has to be suspended from a cable and hydraulic lines having to be attached before it is operational. k. The Snow Removal Equipment (SRE) Building is not available to the contractor. Supply lockable toolboxes to keep materials secured while the work is performed at the site. Power from the SRE is available using extension cords (provide your own extension cords).

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Concrete, Cast-in-Place Concrete.