7920 EVERGREEN WAY 2018-01-01 MF Import

�\,. GEOTECHNICAL ENGIyEEF�., G STUDY E-8879 McDonald's Corporation Page 4 August 30, 1999 With structural loading as e::;�.:::t.�.i, [otal settlement in the range of one inch is anticipated with differential movement of abaut �ne-half inch. Most of the anticipated settlaments should occur during construction as dead loads are appiied. Horizontal loads can be resisted by friction between the base of the foundation and the suppurting soil and by passive soil pressure acting an the face of the buried pertion of the foundation. For the latter, the foundation must be poured "neat" against the competent native soils or backfiiled with structural fill. F�r frictional capacity, a coefficient of .40 can be used. For passive earth pressure, the available resistance can be computed usinfl an equivalent fluid pressure of three hundred fifty (350) pcf. These lateral rssistance values are allowable values, a factor-of-safety of 1.5 has been included. As movement of the foundation element is required to mobilize full passive resistznce, the passive resistance should be neglected if such movement is not acceptable. Footing excavations should be examined by a representative of ECI, prior to placing forms ar rebar, to verify that conditions are as anticipated in this report. Seismic Desiqn Considerations The Puget Lowland is classified ^s Seismic Zone 3 hy the Uniform Building Code 1UBC). The largest earthquakes in the Puget Lowland are widespread and have been subcrustal events, ranging in depth from thirty (30) to fifty-five (55) miles. Such deep events have exhibited no surface faulting. Liquefaction is a ph��nomenon in which soils lose all shear strength for short periods of time during an earthquake. The effects of liquefaction may be large total and/or differeniial settlement for struciur�s with foundations founded in the liquefying soils. Grouncishaking of sufficient duration results in the loss of grain to grain contact and rapid increase in pore w2ter pressure, causinc� the soil to behave as a fluid for short peri�ds o1 time. To have potential for I'quefaction, a soii must be cohesionless with a grain size distribution of a specified range �generally sands and silt); it must be loose to medium-dense; it must be below the groundwater table; and it nwst be subject to sufficient magnitude and duration or groundshaking. Based on the subsurface conditions encountered during our field exploraYion, it is our opinion that the liquefaction potential at the site is negligible due tu the relative density of the soils encountered. I�� accordance with Table 16-J of the 1997 UBC, a soil profile of S�should be used for design. Slab-on-Grade Fioors Slab-on-grade floors may be supported on competent native soil subgrade or on structural fill. Disturbed subgrade soil must either be recompacted or replaced with structural fill. Eerth Conauhante, Inc.