Laserfiche WebLink
Preliminary Report of Geotechnical Exploration <br />Main & Gates Redevelopment; Elk River, Minnesota AMERICAN <br />July 9, 2021 ENGINEERING <br />Report No. P-0001445 TESTING, INC. <br /> <br /> <br /> <br />Page 4 of 10 <br />5.3 Groundwater <br />We encountered groundwater while drilling in Boring SB-3 at a depth of 13 feet which is an <br />elevation of 76 feet. Groundwater was not encountered in any of the other borings at the time <br />they were drilled. As these borings terminated in free draining sands, we judge the water level to <br />be below the depth explored by our borings. <br /> <br />Groundwater levels fluctuate due to varying seasonal and annual rainfall and snow melt amounts, <br />as well as other factors. The Twin Cities area has been in a low precipitation pattern for the last 2 <br />years and the presently observed ground water levels may be lower than normal. Long term <br />monitoring of the groundwater table can be performed with piezometers, which were not part of <br />our work scope. <br /> <br />6.0 RECOMMENDATIONS <br />6.1 Approach Discussion <br />Based on the soil conditions encountered at our boring locations and on the preliminary design <br />information that is available, it is our opinion that the building can be supported on conventional <br />spread footings after removing the fill and topsoil to the underlying alluvial sands and placing <br />engineered fill to attain building subgrade elevation. In our opinion, the existing fill soils are <br />considered undocumented fill soils that were not placed with the intent to provide structural <br />support. <br /> <br />We recommend that full-time observation and testing services be provided by a Geotechnical <br />Engineer/Technician during stripping of the near surface soils and excavation of the previously <br />placed fill with observation of all exposed soils prior to placing new fill or concrete. <br /> <br /> Details of our recommendations for site preparation are as follows. <br /> <br />6.2 Building Grading <br />6.2.1 Excavation <br />To prepare the building area for foundation and slab support, we recommend complete <br />excavation of the fill and topsoil, thereby exposing the naturally deposited alluvial sands. Any <br />remnants or utilities from the previous residence or structures at the site should also be Draft