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Geotechnical Engineering Report lierracon I <br /> Proposed Flight Line Steam Line Project <br /> Boeing Everett Facility • Everett, Washington I <br /> January 17, 2012 • Terracon Project No.: 81115085 <br /> 4.4.1 Foundation Design Recommendations <br /> Design recommendations for shallow spread and mat foundations bearing on at least 6 inches I <br /> of compacted Foundation Material Class A over dense to very dense glacial till soils are <br /> presented below. I <br /> DESCRIPTION Column Wall I Mat <br /> Net allowable bearing pressure 1,2 4,000 psf 4,000 psf 4,000 psf I <br /> 300 pounds per <br /> Modulus of subgrade reaction NA NA square inch per <br /> inch (psi/in) I <br /> Minimum dimensions 24 inches 18 inches 36 inches <br /> Minimum exterior footing embedment I <br /> below finished grade for frost 18 inches 18 inches 18 inches <br /> protection <br /> Minimum interior footing embedment I <br /> below finished grade for frost 12 inches 12 inches 12 inches <br /> protection 1I<1 inch over 30 ' <1 inch over 30 <br /> Approximate total settlement 2 <1 inch <br /> feet feet <br /> Estimated differential settlement 2 < '/z inch < 1/2 inch over 30 < 1/2 inch over 30 I <br /> feet feet <br /> Allowable passive pressure 3 375 pcf(triangular distribution) <br /> Ultimate coefficient of sliding friction 0.45 1 <br /> 1. The recommended net allowable bearing pressure is the pressure in excess of the minimum <br /> surrounding overburden pressure at the footing base elevation. Based upon a Factor of Safety of I <br /> 3. <br /> 2. Assumes existing uncontrolled fill, or any unsuitable fill or soft soils, if encountered, will be undercut I <br /> and replaced with engineered fill. <br /> 3. Assumed that foundation backfill is compacted in accordance with Section 4.2.4. Based upon a <br /> Factor of Safety of 1.5. Passive resistance may be used in combination with sliding friction to resist <br /> lateral loads. I <br /> The net allowable bearing pressures presented in the table above may be increased by one- I <br /> third to resist transient, dynamic loads such as wind or seismic forces. <br /> 4.4.3 Foundation Construction Considerations <br /> The base of all foundation excavations should be free of water and loose soil and rock prior to <br /> placing Foundation Material Class A, and should be prepared as recommended in this report. <br /> Foundation Material Class A should be placed soon after excavating and compaction to reduce I <br /> bearing soil disturbance. Should the soils at bearing level become excessively dry, disturbed, <br /> I <br /> Responsive • Resourceful • Reliable 14 <br />