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A. M. ENGINEERING AND TESTING, INC. ATTACHMENT A SITE PREPARATION and FILL PLACEMENT RECOMMENDATIONS I . General Site Preparation The construction area should be stripped of all topsoil, surface vegetation, trees, roots, debris and other deleterious matter within and five feet beyond the perimeter of the proposed building and in all paved areas . Areas to receive fill should be likewise stripped. Any holes or voids from tree roots, abandoned septic tanks, etc . should be filled as indicated in Section IV. We recommend that a representative of A. M. Engineering and Testing, Inc. inspect the stripped site prior to placing fill. (This can be done while monitoring the proof4olling as recommended below.) The cleared areas should then be proof4oiled and compacted with a 10-ton (minimum) vibratory roller operating at a "slow walk" speed. The vibratory compactor should make at least six overlapping passes over the entire cleared area, three passes in one direction and three more at a right angle to the first three passes . (When proof4olling areas with adjacent or nearby structures, refer to Section II.) Proof4olling helps to detect any soft or loose zones and buried debris. If unstable areas are encountered, the project engineer or the geotechnical consultant should be advised, the matter investigated and the problem resolved. Because the initial proof- rolling is very critical, we recommend that a representative of A. M. Engineering and Testing, Inc. monitor the operation. After proof4olling, the cleared areas should be compacted until the upper two feet of soil aclueve a density of at least 95 percent of the modified Proctor maximum dry density (ASTM D 1557). The compaction should be checked with field density tests. II. Where Vibratory Equipment May Affect Adiacent Structures Where the project site is located adjacent to existing structures that may be damaged by the operation of heavy vibratory rollers, the required densification should be achieved with alternative equipment. Loaders, heavy plate compactors, and "jumping jack ' type compactors have been used successfully. The densification procedure may need to be modified because of reduced capacity of the acceptable equipment. For example, since small plate compactors are generally effective only to a maximum depth of six to eight inches, thinner lifts will be required. III. Excavation and Backfilling Where excavation and backfilling are required, the soils should be removed to the specified depth. Soils that are suitable for use as fill should be stockpiled separately. The excavated surface should be compacted (as described in Section I) so that the upper two feet of the subgrade soil achieve a density of at least 95 percent of the modified Proctor maximum dry density (ASTM D 1557) . The compaction should be checked with field density tests . The site should then be filled to grade in compacted lifts as indicated in Section IV . i