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I I I I I I I I I I I I I I I I I I .1 Transport Tire, Inc. -12- t>1arch 1; 1983 Pavement Design It is our opinion that pavements can be supported on the existing fill soils. We anticipate that silty and clayey sands will comprise the majority of the subgrade soils beneath pavements at this site. We recommend that the bituminous parking areas not be constructed over or in organic topsoils. The organic soils should be removed and should be replaced with select compacted fill. Either non-organic cohesive or granular fill may be used for this purpose. The fill should be placed in loose lifts of 6 to 12 inches, depending on the compaction equipment used, and should be compacted to at least 90% of the Modified Proctor dry density. The best compaction characterisitcs for fill materials will be achieved if the moisture content is maintained at +2% of the optimum moisture as determined by the Modified Proctor procedure. In order to locate any areas of excessively loose or soft materials, which may be detrimental to the long-term performance of pavement areas, we recommend that test rolling be perfonned as defined in Section 2111 of the Standard Specifications of the Minnesota Department of Transportation. Test rolling of the exposed subgrade slab area can be performed using a heavily loaded piece of construction equipment, such as a tandem axle dump truck (25 tons or more gross weight). We recommend that test rolling be performed immediately after stripping operations and not after the subgrade has been allowed to dry in the sun, freeze or become softened due to rainfall. All test rolling should be observed by a qualified soil engineer STS Consultants, Ltd.