4945 OCEAN AVE 2018-01-02 MF Import

GEOTECHNICAL ENGINEERING STUDY Mr. Rick Remsing May 5, 2003 E-10558 Page 6 A slope stability analysis was performed on the site on the cross section shown on Plate 2. The ten most critical failure surfaces are shown on the printouts in Appendix C for existing and post construction conditions. The sandy native soils were modeled with cohesion of fifty (50) pounds per square foot (psf) and a phi angle of 34 degrees and the native silt soils were modeled with cohesion of five hundred (500) psf and a phi angle of 28 degrees. Foundations adjacent to the slope should be deepened as necessary to obtain a minimum of ten feet horizontal distance from the face of the foundation to the face of the slope as shown on Plate 3. Foundations Based on the results of this study, it is ECI's opinion the proposed residence may be supported on a conventional spread and continuous footing foundation bearing on competent native soil. For frost protection considerations, exterior foundation elements should be placed at a minimum depth of eighteen (18) inches below final exterior grade. Interior spread foundations can be placed at a minimum depth of twelve (12) inches below the top of slab, except in unheated areas, where interior foundation elements should be founded at a minimum depth of eighteen (18) inches. With foundation support obtained as described, for design, an allowable bearing capacity of two thousand (2,000) psf for competent native soil can be used. Continuous and individual spread footings should have minimum widths in accordance with the Uniform Building Code. Loading of this magnitude would be provided with a theoretical factor -of - safety in excess of three against actual shear failure. For short-term dynamic loading conditions, a one-third increase in the above allowable bearing capacities can be used. With structural loading as expected, total settlement in the range of one inch is anticipated with differential movement of about one-half inch. Most of the anticipated settlements should occur during construction as dead loads are applied. Eanh Consultants, Inc.