406 SE EVERETT MALL WAY BASE FILE 2018-01-02 MF Import

Auto Mall Associates E-2976 May 16, 1986 Page 8 due to changes in rainfall amounts, surface drainage or other factors. If seepage is encountered in excavations, the water should be drained away from the site by use of drainage ditches, perforated pipe or French drains, or by pumping from sumps interconnected by shallow connector trenches at the bottom of the excavation. We suggest that appropriate locations of subsurface drains, if needed, be established during grading operations by a represen- tative of Earth Consultants, Inc., at which time the seepage areas, if present, may be more clearly defined. The excavation and site should be graded so that surface water is directed off the site and away from the tops of slopes. Water should not be allowed to stand in any area where buildings, slabs, or pavements are to be constructed. During construction, loose surfaces should be sealed at night by compacting the surface soils to reduce the infiltration of rain into the soils. Final site grades should allow for drainage away from the building founda- tions. We suggest that the ground be sloped 3 percent for a distance of at least ten feet away from the buildings except in areas that are to be paved. Pavement Areas All parking and roadway areas may be supported on native soils or existing fills provided these soils can be compacted to 95 percent density and are stable at the time of construction. Structural fill and/or fabric may be needed to stabilize soft, wet or unstable areas. In most instances twelve (12) inches of granular fill will stabilize the subgrade except for very soft areas where additional fill could be required. The upper twelve (12) inches of pavement subgrade should be compacted to at least 95 percent of the maximum density. Below this level a compactive effort of 90 percent would be adequate. The pavement section for liohtly loaded traffic and parking area hould consist of two inghe_a_Of._aSphalt concrete tAC:) over tour £our _nCns T CrUSneu Les base (CRB) or three inches o asphalt treated base (ATB). Heavier 1 ao ded—areas would require thicker sections. We will be pleased to assist you in developing appropriate pavement sections or specifications for heavy traffic zones, if needed. Site Preparation and General Earthwork The building and pavement areas should be cleared of all slabs, foundations, trees, existing utilities, surface vegetation, all organic matter and any other deleterious material. It is anti- cipated that a stripping depth of six (6) to eighteen (18) inches will be required. Stripped materials should be removed from the site or stockpiled for later use in landscaping, if desired. The Earth Consultants, Inc.