7425 HARDESON RD BASE FILE 2016-01-01 MF Import

� �� i� GEOTECHNICAL ENGINEERING STUDY Trace and Associates July 19, 2005 E-11880 Page 8 �� The proposed site improvements will also include a new stormwater conirol vault. A � soil consisting of sandy silt with organics was encountered at approximately 9 feet below existing grade in Test Pit TP-6 within the approximate footprint of the proposed �1 vault. Based on preliminary design information provided by the client, the bottom of the �� vauit will be located at or near the elevation of the organic soil layer. If organic soils are encountered at the construction subgrade elevation within th�e vault, the organic soils � should be overexcavated and replaced with structural fill. Once the organic soil is removed, the vault may be supported on a conventional spread and continuous footing � foundation system bec ring on at least 12 inches of newly placed structural fill or existing fill compacted in-��lace to the requirements of structural fill. � For frost protection, exterior foundation elements should be placed at a minimum depth of 18 inches below tinal Exterior grade. Interior spread foundations can be placed at a niinimum depth of 12 inches below the top of slab, except in unheated areas, where � interior foundation elements should be founded at a minimum depth of 1 S inches. Continuous and individual spread footings should have minimum widths of 18 and 24 inches, respectively. �� � � With foundation support obtained as described, for design, an allowable soil bearing capacity of 2,500 psf may be used for structural fill. The allowable soil bearing capacity described above is provided with a theoretical factor-of-safety in excess of 3.0 against actual shear failure. For short-term dynamic loading conditions, a one-third increase in the above allowable bearing capacity may be used. With structural loading as expected, total settlement of less than 1-inch is anticipated with differential movement of less than 1/2-inch. Most of the anticipated settlement � should occur during construction as dead loads are applied. � Horizontal loads can be resisted by friction between the base of the foundation and the supporting soil and by passive soil pressure acting on the face of the buried portion of the foundation. For the latter, the foundation must be poured "neat" against � competent native soils or backfilled with structural fill. For frictional capacity, a coefficient of 0.35 can be used. For passive earth pressure, the available resistance � can be computed using an equivalent fluid pressure of 300 pounds per cubic foot (pcf). Tliese lateral resistance values are allowable values; a factor-of-safety of 1.5 has been included. Unless overlain by pavements, the passive pressure should be neglected in � the upper 1 toot. As movement of the foundation element is required to mobilize full passive resistance, the passive resistance should be neglected if such movement is not acceptable. � � Earth Consulian�s. Inc.