20 Civic Center Plaza - Soils Report

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Griffin Realty SA. Inc.-Geotechnical Investigation Law/Crandall Project 70131-7-0261.0001 July 8.1997 prior to backfilling, holes 2 to 3 inches in diameter and spaced at 10 feet on centers should be cored through the floor slab of the existing basement. Site Preparation After the site is cleared and existing fill soils are excavated as recommended, the exposed natural soils should be carefully observed for the removal of all unsuitable deposits. Next, the exposed soils should be rolled with heavg compaction equipment. At least the upper 6 inches of the exposed soils should be compacted to at least 90% of the maximum dry density obtainable by the ASTM Designation D 1557-91 method of compaction. Compaction Any required fill should be placed in loose lifts not more than 8 inches thick and compacted. The fill should be compacted to at least 90% of the maximum density obtainable by the ASTM Designation D1557-91 method of compaction. The moisture content of the on-site soils at the time of compaction should vary no more than 2% below or above optimum moisture content. Material for Fill The on-site soils, less any debris or organic matter, can be used in required fills. Cobbles larger than 4 inches in diameter should not be used in the fill. Any required import material should consist of relatively non-expansive soils with an expansion index of less than 35. The imported materials should contain sufficient fines (binder material) so as to be relatively impermeable and result in a stable subgrade when compacted. All proposed import materials should be approved by our personnel prior to being placed at the site. 6.9 GEOTECHNICAL OBSERVATION The reworking of the upper soils and the compaction of all required fill should be observed and tested during placement by a representative of our firm. This representative should perform at least the following duties: 17