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Geotechnical Report 2018 PMP Streets Arden Hills, Minnesota WSB Project No. 010111-000 Page 6 Table 2: Existing Roadway Soil Boring Profiles Boring No. Bituminous Thickness (inches) Aggregate Base Thickness (inches) Subgrade Soils (Upper 4 feet) PB-1 6 9 Lean Clay with Sand PB-2 6 8 Fill (Sand with Silt, Clayey Sand, Lean Clay) PB-3 8 5 Lean Clay with Sand PB-4 4 6 Fill (Clayey Sand), Lean Clay with Sand PB-5 3 4 ½ Fill (Sandy Lean Clay), Silty Sand PB-6 5 7 Fill (Sandy Lean Clay), Lean Clay PB-7 4 7 Fill (Clayey Sand), Lean Clay with Sand PB-8 6 ½ 4 Fill (Lean Clay with Sand), Silty Sand PB-9 5 4 Fill (Clayey Sand, Lean Clay with Sand) PB-10 4 4 ½ Lean Clay with Sand, Sandy Lean Clay PB-11 7 7 Fill (Clayey Sand), Lean Clay with Sand PB-12 3 ½ 6 Fill (Clayey Sand), Lean Clay with Sand PB-13 6 5 Fill (Sandy Lean Clay), Lean Clay with Sand PB-14 5 6 Fill (Sand with Silt), Lean Clay with Sand PB-15 3 5 Fill (Sand with Silt) PB-16 3 - Fill (Sandy Lean Clay), Peat PB-17 4 - Fill (Sandy Lean Clay), Lean Clay with Sand PB-18 5 - Fill (Sandy Lean Clay), Lean Clay with Sand After excavation to the top of subgrade elevation, we recommend removing any organic soils encountered within 3 feet of the top of subgrade and any peats encountered within 4 feet of the top of subgrade and replacement with an engineered fill. If wet clays are exposed in the bottom of the excavations, we recommend subcutting 2 feet and replacing with a granular fill. Any sands encountered at the bottom of excavation should be surface compacted with a 10-ton vibrating roller compactor with a minimum width of 60 inches. After preparation of the area as recommended above, proof-roll tests should be utilized with a loaded dump truck to help identify areas that may require corrective action such as scarifying, disking, and compaction or sub-excavations. We also recommend a proof-roll be performed again on the aggregate base just prior to placement of the bituminous pavement. Traffic data was not available for these roadways. We estimated that Average Daily Traffic (ADT) would be up to 500 vehicles. Our design is based on a twenty (20) year design life of the pavement section. Once the site has been prepared as recommended, we anticipate the prepared subgrade soils will consist mostly of lean clays with sand, silty sands, clayey sands, and sands with silt. These soils would have estimated R-values ranging from 10 to 50. W e recommend using an R-value of 12 for design at this site.