2023-05-10 CC Packet - Laserfiche WebLink

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Proposal for Geotechnical Evaluation May 3, 2023 1737 Main Street, Centerville, MN footprint are not suitable for drill rig set-up, alternative locations will be drilled in locations as close as practical. The borings will be drilled to these depths or to refusal depending upon subsurface conditions encountered. This planned exploration program results in approximately 60 linear feet of borings. The Minnesota public utility locating service, "Gopher State One Call," will be contacted by our subcontracted driller prior to our field program. VIEAU/GZA will also contact a private underground locating service to provide secondary clearance of the soil boring locations. The soil borings will be advanced using hollow -stem auger drilling techniques and split -spoon standard penetration tests (SPTs) will be conducted at 2%-foot intervals to 15-feet bgs, and 5-foot intervals thereafter. VIEAU/GZA will also monitor the groundwater conditions during and after drilling if encountered. The SPT samples will be supplemented with relatively undisturbed Shelby tube samples, if conditions encountered are suitable. Soil samples will be collected for classification and select laboratory testing. The borings will be located in the field using a handheld GPS unit with accuracy of±3 feet. Surface elevations at the test locations will be determined relative to a specific datum using elevation data provided by the Client. Ground surface elevations, if provided, are assumed to be accurate to the nearest ±1-foot. If more accurate locations/elevations of the borings are required, a surveyor should be contacted to stake boring locations in the field prior to commencement of fieldwork. GZA can coordinate a surveyor for additional cost, if requested. Excess auger cuttings from the borings will be thin spread and disposed on -Site. After the depth to boring cave-in or groundwater are measured in the borings, the borings will be abandoned in accordance with State of Minnesota and local requirements. This proposal is based on our assumption that the Site is accessible by either a truck -mounted or an all -terrain drill rig to conduct the borings. For an additional cost, limited tree limb clearing and/or matting can be placed below the rig tracks/tires in green space areas to reduce potential damage caused by the rig. The Client should notify VIEAU/GZA if tree clearing and/or matting is required. VIEAU/GZA will notify Client if conditions are encountered that require a change in scope. Task 2 - Classification and Laboratory Testing A geotechnical engineer or geologist will classify soil samples that are recovered from the subsurface exploration in general accordance with ASTM D2488, Standard Practice for Description and Identification of Soils (Visual -Manual Procedure). Geotechnical laboratory tests will be performed on select soil samples to assist with the development of geotechnical design parameters. Depending on the subsurface conditions encountered, we anticipate submitting samples for gradation and moisture content. If cohesive soils are encountered, additional testing consisting of Atterberg limits, one-dimensional consolidation, and unconfined compression may be conducted. Additional tests may be assigned if soil conditions warrant the additional effort. Task 3 - Engineering Analyses and Geotechnical Recommendations VIEAU/GZA will prepare a geotechnical engineering report based on the subsurface conditions that are encountered at the boring locations and the results of the field and laboratory testing. The geotechnical engineering report will include the following: • Descriptions of the soil and groundwater conditions encountered in the borings; • A summary of the geotechnical field and laboratory test results; • Borehole water levels observed during and after drilling; 2