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Geotechnical Report 2018 PMP Streets Arden Hills, Minnesota WSB Project No. 010111-000 Page 3 3. EXPLORATION RESULTS 3.1 Site and Geology The Ramsey County Geologic Atlas indicates the surficial soils at this site are mostly glacial deposits consisting of a mixture of silty sands, clayey sands, and lean clays with sand. The roadways were bituminous paved at the time of drilling. The borings were completed through the drive lanes of the roadways. 3.2 Subsurface Soil and Groundwater Conditions The boring profile generally consisted of pavement section materials and fills overlying coarse alluvial deposits and glacial deposits. Pavement Section The bituminous asphalt thickness ranged from about 3 to 8 inches and averaged about 5 inches at our boring locations. The aggregate base thickness ranged from about 4 to 9 inches where encountered and averaged about 6 inches. Borings PB-16, PB-17, and PB-18 did not encounter a discernable aggregate base layer. Fills The fills encountered in the borings generally consisted of a mixture of clayey sands, sandy lean clays, and sands with silt. Fills extended to depths of about 2 to 7 feet below grade. Organics Boring PB-9, PB-15 and PB-16 encountered organic clays and peat below the fills. These organic clays and peat deposits were black in color and were wet. Fine Alluvium Boring PB-6 encountered lean clays that were brown in color and wet. Glacial Deposits Glacial deposits were the predominant soils encountered in our borings. These deposits consisted mostly of sands lean clays, lean clays with sand, clayey sands, and sands with silt. These soils were brown to gray in color and were moist to wet. 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 borings completed and remarks regarding the material strengths of the soils. Table 1: Penetration Resistances Soil Type Classification Penetration Resistances Remarks Fills - 2 to 10 BPF Variable compaction Organics OL, PT 1 to 5 BPF Average 3 BPF Very soft to soft Generally very soft Fine Alluvium CL 5 BPF Soft Glacial Tills SM, SC, CL 3 to 21 BPF Average 12 BPF Very loose to medium dense Generally medium dense