4711 GLENHAVEN DR 2016-01-01 MF Import

r . recommend that the foundation wa11s along the southem perimeter of the building be eztended 4 feet above ouuide grades. This feature wiil mitigate structural damage from potendal future, shallow-seated landsiide debris flows from the slope above. It should be noted that the area bounded by lines extending downward at 1H:1V from any footing must not intersect another footing or sofUdisturbed natural or fill soils. In addition, a 1.SH:1 V line extending down from any footing must not daylight because sloughing or raveling may eventually undemune the footing. Thus, footings should not be pia=ed near the edge of steps or cuts in the bearing soils. Lateral loads can be resisred by friction between the foundation and the supporting nawral or compacted fill subgrade, or by passive earth pressure acting on the buried portions of the foundations. Tl�e foundations m�st be poured "nea[" against the existing soil, or backfilled with - a compacted fill meeting the requireme.n[s of structural fill. We recommend the following design _ parameters: ' • Equivalent passive fluid density = 300 (pounds per cubic foot) • Coefficient of friction = 0.35 The above values include a factor of safery of 1.5. Anticipated setdement of footings founded on the natural, medium dense, silry fine sand and site soils prepared as previously reconunended should be on [Ue order of 1 inch or less. Iiowever, disturbed soil not removed from footing areas prior to placing the footings could result in increased se�tlemen�s. Footing subgrades should be inspected by AESI prior to placing concrete to veriCy tl�at d�e design bearing capacity of the soils has been attained and d�at construction confornu with the recommendations coniained in this report. Such - inspections may be required by the governing municipality. Perimeter footing drains should be provided as discussed under thc section on Drainage Considerations. 10.1 Retainine Walls To achieve the daylight basement elevations of the residence and to retain tbe upper slope solls witlrin the parking area as proposed, we anticipate that foundation retaining walls ranging from about 6 to 12 feet in height will be required. Due te the presence of loose fill soils wtvch exrend to depttu of approximately 12 feet below the base of the proposed parking area, we recommend diat the retaining walls consuvcted for this area be supported using drilled picr foundations. The piers would need to extend through the fill and be embedded within the underlying de��se [ill soiis. I'lease refer to the desien recommendations contained in the following Drilled Pier section of ttiis rcport. The proposed retaining walls should be designed ro resist tl�e lateral earth pressures imposed by the mtained soils. \Valis diat are designed to yield 0.001H, where H equals the heieht of the wall, may be designcd to resist the lateral earth pressure imposed by an equivalent fluid with a I1