7825 EVERGREEN WAY 2018-01-01 MF Import

'i . . �� Embar Equities Corporation E-2773 hovember 4, 1585 Page 4 increase in the above bearing pressures may be used when consider- ing short term wind or seismic loads. For the above 3esign criteria, it is anticipated that total settlements of footings founded on medium dense to dense native soils and on fills less than five feet thick will be less than one inch, with differential settlement� of one-half inch or less. Almost all settlements should occ�: during construction. If any continuous footings are located partially in cut and partially in fill, we recortonend that the structural engineer consider adding additional reinforcement in the footings aud footing walls near the cut-fill transition lir.e to minimize the possibility of atructural damage due to differential settlement. Isolated spread footings should be extended to natural soils in the transition zone. Lateral loads due to wind or seiamic forces may be resisted by friction between the foundations and the supporting compacted fill subgrade or by passive earth pressure on the foundations. For the latter, the foundations must be poured "neat" against the existing soil or backfilled with a compact fill meeting the requirements of eitructural fi11. A coefficient of friction of 0.40 may be us�ad bet.ween the structural foundation concrete and the supporting subgrade. The passive resistance of undiaturbed natural eoils and well compacted _'ill may be taken as equal co the pressure of a fluid having a density of three hundred fifty (350) pounda per cubic foot (pcf). We recortunend that drains be placed around all perimeter foot- � ings. The draina should be co:�strucred wit'� a four inch diameter � perforuted pipe bedded and covered with free draining gravel. The drains should have a positive gra3ier.t towards suitable discharge facilities. The footing drainage system should not be tied into the roof drainage system until the �jrains are tightlined well away .`:rom the building. The footing excavation should be backfilled with granular soil except for the tep foot which should be backfilled with a relatively impermeable soil such as silt, clay or topsoil. Alternatively, the aurfacw can be �ealecl with asphalt or concrete pavements. Slab-on-Grade Floore Slab-on-grade floors may be supported on the rnmpacted compe- tent native soil subgrade or on structural fill. Any disturbed native eoils must either be recompaated or replaced with structural fill. The slab Bhould be provided with a minimum of four inches of £ree firaining sand or gravel. We aleo recommend that a vapor barrier such ae a 6 mil plastic membrane be placed beneath the slab to reduce water vapor tranemission through the Ear1h Consultants, Inc.