Geotechnical Services - RFP.docx

REQUEST FOR PROPOSAL

GEOTECHNICAL SERVICES – HIGHWAY 103 WATERLINE

A. Overview of the Project

Project Description: The proposed project will consist of the construction of a new 16” C900 PVC waterline in Clear Creek County, outside of the City of Idaho Springs (City, Owner). The Work will be split into two phases. Phase 1 will include approximately 4,860 LF of 16” C900 PVC waterline and Phase 2 will include approximately 11,760 LF of 16” C900 PVC waterline. Each phase will include the necessary labor, supervision, equipment, tools, and materials for construction of that section of the 16” C900 PVC waterline. Work includes but is not limited to hydrants, valves, tie-ins, new service line connections, erosion control, earthwork, cutting, patching, and repaving of roads, and all appurtenances as specified and required for a complete and functional system. The work also includes up to four creek crossings under a Nationwide Permit. This RFP is for geotechnical testing services for Phase 1 only.

Project Area: The pipeline will follow Mount Bluesky Road (Highway 103) and begin at the City of Idaho Springs Water Treatment Plant at 3407 Chicago Creek Road and will terminate approximately 800 feet south of Interstate 70 at exit 240, reaching approximately 16,620 linear feet in length.

Site Access: Site access is open, and the required equipment for construction testing can be transported to the testing locations.

B. Scope of Services

Work for this proposal will cover construction testing along the planned waterline for Phase 1. A Limited Geotechnical Evaluation was performed by Ground Engineering in July 2023 and can be provided upon request. Below are the construction tests requested, and number of tests anticipated:

1. Soil Proctors

a. Provide two moisture-density relationship tests (proctor) ASTM D698 or relative density tests (ASTM D4253/D4254) for each type of fill material

i. Assume three proctors on native material, and one proctor on imported fill material

ii. Provide unit cost for additional soil proctors.

2. Pipe Embedment and Backfill Compaction Test

a. Estimated Linear Feet of Trench: 4,860

b. Estimated Number of Backfill Tests: 125 (25 locations along pipeline)

i. Application: One in-place compaction test every 200 linear feet of trench in the compacted embedment zone and at every 1.5 feet of vertical lift of backfill materials per ASTM D6938

ii. Assume at least one set of tests per day. Multiple visits per day may be warranted depending on productivity rates.

3. Asphalt Concrete Mix Sampling and Testing

a. Uncompacted asphalt concrete mix

i. Asphalt cement content: ASTM D2172 (AASHTO T164)

ii. Maximum Specific Gravity: ASTM D2041 (AASHTO T209)

b. Compacted asphalt concrete mix

i. Bulk density: ASTM D1188 (AASHTO T166)

c. Application: Perform at least one test for each day’s paving but not less than one test per each 4,000 SF of each lift – 4 lifts total

i. Estimated Tons of Asphalt Paving: 1,760

ii. Estimated Square Feet of Asphalt Paving: 43,000

iii. Minimum Number of Tests: 44 Minimum

iv. Please provide quote for additional tests each day (up to 88 tests total)

4. Concrete Cylinder Compression Test

a. Cubic Yards of Concrete for Encasement: 20

b. Estimated Number of Tests: 3 (Three stream crossings that will require concrete encasement) Application:

Provide one set of 6 cylinders for each concrete encasement Test a minimum of one cylinder in each set at 7 days Test at least two 6x12 cylinders or at least three 4x8 cylinders in each set at 28 days The other two cylinders to be used as directed by Engineer at any time Engineer will evaluate in accordance with ACI 214 and 318 Make, cure, store, and deliver cylinders in accordance with ASTM C31 Test in accordance with ASTM C39 Mark or tag set of test cylinders with the date and time of day the cylinders were made, the location in the work where the concrete represented by the cylinders was placed, the delivery truck or batch number, the air content, and the slump

C. Schedule

Indicate in proposal duration needed to perform field work and complete geotechnical report. The Notice to Proceed was issued on February 18, 2025.

The City will receive proposals until end of day on February 28, 2025, electronically through Rocky Mountain E-Purchasing System – BidNet Direct (BidNet). Proposals shall be clearly marked “City of Idaho Springs – Geotechnical Services – Highway 103 Waterline”.

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