1318 37TH ST Geotech Report 2018-01-02 MF Import

. James Pirie 1 JN 97072 � March 18, 1997 Page 9 could be required. The subgrade should be evaluated by G�otech Consu!tants, Ir+c., after the siYe is stripped and cut to grade. Recommendations for the r,ompaction of structural fill beneath i pavements are given in a later sub-section entitled General Earthwork and Structurel Fill. The performance ef site pavements is directly related io the strength and siability of the underlying subgrade. � The pavement for lightly loaded traffic and parking areas should consist of 2 inches of asphalt �I concrete (AC) over 4 inches of crushed rock base (CRB) or 3 inches of asphalt-treated base (ATB). I Wa recommend providing heavily loaded areas with 3 inches of AC over 6 inches of CFtB or 4 inches of ATB. Heavily loaded areas are typically main drveways, dumpster sites, or areas with truck traffic. The pavement section reconmendations and �uidelines presented in th?s report are based on our experience in the afea and on what has been successful in simila� siivations. Some maintenance and repair of limited areas can be expected. To provide for a design without the neec+ for any repair would be uneconomical. General Earthwork and Struc4urai Fill Ali building and pavement areas should be stripped of surface vegetation, topsoil, organic soil, and other deleterious material. The stripped or removed m�terials should not be mixed with any � materials to be used as structural fill, but they coulc be used i� non-structural areas, such as landscape beds. Structural fill is defned as any fill placed under a building, betiind permanent retain�ng or foundation walls, or in other areas where the underlying soil needs to �upport loads. All structural fill should be placed in horizontai lifts with a moisture content at, or nea�, the optimum moisture r,ontent. The optimum moisture content is that moisture content that results in the great�st compacted dry density. The moisture content of fill is very important and must be closely controlled during the filling and compaction process. The allowable thickness of the fill lift wili depend on the material type selected, the compaction equipment used, and the number of passes made to compact tha lift. The loose lift thickness should not exceed 12 inches. We recommend testing the fill as it is placed. If the fill is not I compacted to specifications, it can be recompacted before another lift is placed. This eliminates the need to remove the fill to achieve the required compaction. The following table presents recommended relative compactions for structural fill: i Minimum � Location of Fill Placement Relative Compaction Beneath footings, slabs, 95% or walkways Behind retaining walis 90°/a d 'q� GEOTGCH CONSULTANTS,INC.