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1629 Lena Ct - Soils testing letter?- CINSTANT TESTING COMPANY ?'I T j 7125 West 1'6th Street • Suite 500 • Savage. YIN 5i;78 PHONE: 9?;2-890-7166 • FAX: 952-390-585" June 12, 2003 'IWCzr4? ??kAttn: Andy JU?? Manley Land Development ??0? 2113 Cliff Drive Eagan, Minnesota 55122 RE: Inspection - Centennial Ridge 2nd Addition Eagan, Dakota County, Minnesota As requested, a site visit was conducted on June 10, 2003 to evaluate soil consolidation within graded pads for commercial buildings #1 and #2 of the Centennial Ridge 2nd Addition. A grading and construction plan prepared by Pioneer Engineering Mohagen Hansen Architectural Group, dated March 19, 2003 was provided prior to the inspection. Also referenced, subsurface geotechnical report #00004 dated January 25, 2000 provided by Test Drilling Company. 35th ANNIVERSARY 2003 and Allied our observations, and data provided by the soil borings, indicates quantities of undocumented fiii, primarily within the northeast section of the development. A grade stake, located near the NE corner of building pad #2, indicated a existing elevation of 947.0. Based on topographic elevations provided by the preliminary grading plan and proposed building elevations of 948.0 and 949.0, we would conclude that recent grading has added 3 1/2 to 4 feet of fill to the building pads. To evaluate the consolidation and relative loadbearing capacity of the inpiace sui:s, dynamic cc:e per?tromete: tests were conducted approximately 25 feet on center from the end of each pad. Buil3ing pad #1:-"test A" (west end), "test B" (east end), building pad #2: "test C" (north end) and "test D" south end. The dynamic cone penetrometer (DCP), uses a eight kilogram (17.6 pound) hammer to drive a 20 millimeter diameter conical point into the soil, with the penetration recorded in millimeters per blow. At the referenced locatians, the DCP was advanced a total of: test "A"- 641 millimeters (25.2 inches), test "B" - 841 millimeters (33.1 inches), test "C" - 1476 millimeters (42.4 inches) and test "D"- 686 millimeters (27.0 inches). A composite, per blow, penetration average of 32.2 MM, 30.0 MM, 65.2 MM and 24.7 MM respectively was racorded. Our experience with the DCP in similar soils to those at the site, would indicate a average penetration N- ti value of N-10.5 for tests "A" &"B", (bldg #1) and N-4.5 test "C" & N-12.0 test "D" (bldg #2). This N-value, is an empirical relationship we have established to equate the dynamic cone data to the more familiar blows per foot (BPF) standard penetration soii boring test. Based on this data, we would predict a relative loadbearing capacity of 1500 PSF within the zone penetrated for test "C" (north end bldg pad #2), which indicates a DCP penetration value greater than 50 MM per blow. The remaining tests conducted, indicate a loadbearing capacity of 3500 PSF. As the referenced tests represent a limited evaluation of soil consolidation within the building pads, It is recommended that the soil conditions be reviewed at footing elevation during construction. We wouid expect the loadbearing capacity to improve or meet the target capacity of 2500 PSF, for the north end of building #2, when excavated to frost footing elevation. jincerely, Instaryt-Zesting Company 3 'arp-S)Eand3 s h Seniq? Inspect Chg: #605 - ?,/Hours / #306 - 4 (DCP) / #612 - 22 Miles