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Geotechnical Report Arden Oaks Street Improvements Arden Hills, Minnesota WSB Project No. 014297-000 Page 3 3. EXPLORATION RESULTS 3.1 Site and Geology The borings were performed on existing roadway alignments within the Arden Oaks neighborhood. The Ramsey County Geologic Atlas indicated the surficial geology in the area of our borings are glacial deposits. These deposits consist primarily of till consisting of silty and clayey sands to clay. 3.2 Subsurface Soil and Groundwater Conditions The boring profile generally consisted of a pavement section overlying fill and/or naturally deposited glacial till. Pavement Section The bituminous thickness ranged from about 5 to 6 ½ inches and averaged over 5 ½ inches. The underlying aggregate base ranged from about 5 to 13 inches and averaged about 7 ¾ inches. Fill Borings PB-E, PB-G and PB-H encountered fill beneath the aggregate base. The fill consisted mainly of sandy lean clay that was dark brown to brown and gray in color and moist. Naturally Deposited Soils Below the pavement section or fill, our borings encountered and terminated in glacially deposited soils. The glacial till consisted of sandy lean clay that contained gravel, was brown and moist. Glacial outwash consisting of sand was encountered beneath the till at a depth of about 10 feet in Boring PB-E. The fine- to coarse-grained sand contained gravel, was brown and considered moist. 3.3 Strength Characteristics The penetration resistance N-values of the materials encountered were recorded during drilling and are indicated as blows per foot (BPF). Those values provide an indication of soil strength characteristics and are located on the boring log sheets. Also, visual-manual classification techniques and apparent moisture contents were also utilized to make an engineering judgment of the consistency of the materials. Table 1 presents a summary of the penetration resistances in the soils for the standard penetration test borings completed and remarks regarding the material strengths of the soils. Table 1: Penetration Resistances Soil Type Classification Penetration Resistances Remarks Fill CL 5 to 7 BPF Variable compaction Till CL 4 to 20 BPF Very soft to hard Outwash SP 23 BPF Medium dense The preceding is a generalized description of soil conditions at this site. Variations from the generalized profile exist and should be assessed from the boring logs, the normal geologic character of the deposits, and the soils uncovered during site excavation. 3.4 Groundwater Conditions WSB took groundwater level readings in the exploratory borings, reviewed the data obtained, and discussed its interpretation of the data in the text of the report. Groundwater was not observed during or shortly after drilling and sampling. It should be noted that our borings were not left open long enough to allow for groundwater stabilization. In clay soils, it may take a long time (longer than what was available with our time on site) for water to enter a bore hole and rise to DRAFT REPORT 7-8-2021