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Prior to placement ofthe slab, we recommend that the subgrade soil be moisture <br />conditioned under the observation of the geotechnical consultant. In order to <br />reduce the potential for shrinkage cracks in the concrete during curing, we <br />recommend that low water-cement ratio (.45 or less) concrete be placed with a <br />maximum slump of 4 inches based on ASTM D-143. The slump should be <br />periodically checked prior too placement. We further recommend that crack <br />control joints be provided in the slabs in accordance with the recommendations of <br />a structural engineer to reduce the potential for distress due to minor soils <br />movements and concrete shrinkaee. Concrete should be placed in accordance <br />with "ACI Manual of Concrete Practice," sections 301 Specification for Structural <br />Concrete for Buildinqs and 305R Hot Weather Concreting <br />10.4 Laterd Reristrncc ind Earth Pressures <br />The following recommendations may be used for shallow footings on the site. <br />Foundations placed in firm, well-compacted, fill material may be designed using a <br />coefficient of friction of 0.25 (total frictional resistance equals coefiicient of friction <br />times the dead load). A design passive resistance value of 150 pounds per square foot per <br />foot of depth (with a maximum value of 1800 pounds per square foot) may be used. The <br />allowable lateral resistance can be taken as the sum of the frictional resistance and the <br />passive resistance provided the passive resistance does not exceed two-thirds of the total <br />allowable resistance. The passive resistance values may be increased by one-third when <br />considering loads ofshort duration such as r.vind or seismic forces. <br />J <br />Report of Soils Investigation Page 21 of27 <br />2215 South Standard Ave., Proposed Addition Job No. 40-0613 <br />Santa Ana- Califomia April 5. 1999 <br />10.3.4 Moisture Conditionins and Concrete Placement <br />{ <br />l