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A. M. ENGINEERING AND TESTING, INC. Geotechnical Exploration Indian River County Parks Maintenance Complex, IRC Project No. 0710 A . M. Engineering Project No. PSL1825 - 1 i Earthwork Recommendations Fill should be "clean" sand with less than five percent fines (percent of dry weight passing a U. S . x No . 200 sieve). Higher fine contents can be used but more construction control is necessary . f Backfill behind walls should be very pervious, with no more than three percent fines . Hand operated equipment should be used when in close proximity to walls or other structures that could be adversely affected by vibrations or heavy equipment. t Where fill is to be placed on the existing � und, the surface must be previous section. The outer edges of the fill should extend uffic ently bey ndreparedsthe buildingsinch icatc' intto provide slopes with a minimum horizontal to vertical ratio of4(H): 1 (V) from approximately five feet outside the building perimeters to the existing grade. The fill should be placed in 12-inch thick compacted lifts with each lift compacted to at least 95 percent of the modified Proctor maximum dry density (ASTM D 1557). The compaction should be checked with field density tests. Fill that is -placed in confined areas such as utility trenches. or. holes should be compacted -in six to eight inch thick lifts to at least 95 percent of the modified Proctor maximum dry density (ASTM D 1557). Groundwater Control Groundwater was encountered between depths of 3 '/4 and 6 feet during our explorations . We estimate that the average wet season high water table will be strongly influenced by the adjacent Lateral ` G ' Canal , and will be 1 to 2 feet above the canal level depending on the distance to the canal . However, should rainfall intensity and duration or total rainfall quantities exceed the normally anticipated rainfall quantities, the groundwater levet may exceed our estimate of the average wet season high groundwater level . Some dewatering may be required for excavations that will extend to within 2 feet above the groundwater table and for deep excavations such as sewer and utility trenches. Although the actual dewatering methods should be determined by the contractor, the use of well points and sump pumps in the excavation usually is adequate for most dewatering operations. We recommend that the contract documents require an accurate determination of the ground water level immediately prior to initiating any dewatering operation. Positive drainage should be maintained at the site during construction and throughout the life of the project. 6