2802 HOYT AVE EVERETT ELKS Geotech Report 2018-01-02 MF Import

Geotechnical-Engmeering F..valuation Everett Elks Club November 2, 2006 NGA File No. 751106 Page 10 site at the time the holes are drilled. The holes should not be left open for any length of time, as that may increase the potential for caving and water seepage to impact wall installation. If groundwater seepage is encountered, we recommend that the concrete be tremied from the bottom of the excavations to displace the groundwater to the surface. Extra Portland Cement may also be placed in the bottom of the excavations to reduce the affects of seepage. The spoils from the soldier pile excavations are expected to be moismrc-sensitive materials and should be hauled off site. We should be retained to observe shoring wall installation. Foundations Building foundations independent of the shoring wall, as well as the foundations for the sky bridge, can be designed as conventional shallow spread foundations placed on undisturbed medium dense or better native soils, or be supported on structural fill or rock spalls extending to those soils. Where less dense soils are encountered at footing bearing elevation, the subgrade should be over -excavated to expose suitable bearing soil. The over excavation may be filled with structural fill, or the footings may be extended down to the bearing native soils. If footings are supported on structural fill, the fill zone should extend outside the edges of the footings a distance equal to one-half of the depth of the over -excavation below the bottom of the footings. Footings should extend at least 18 inches below the lowest adjacent finished ground surface for frost protection and bearing capacity considerations. Minimum foundation widths of 18 and 24 inches should be used for continuous and isolated spread footings, respectively, but footings should also be sized based on anticipated loads and allowable soil bearing pressure. Standing water should not be allowed to accumulate in footing trenches. All loose or disturbed soil should be removed from the foundation excavation prior to placing concrete. I -or foundations constructed as outlined above, we recommcnd an allowable design bearing pressure of not more than 2,500 pounds per square foot (pso be used for the footing design for footings founded on the medium dense or better glacial soils or structural fill extending to the native competent material. The foundation bearing soil should be evaluated by a representative of our firm. Higher bearing capacities may be achieved for wider footings supported on the very dense unweathered material. We should be consulted if higher bearing pressures are needed. Current IBC guidelines should be used when NELSON GEOTECHNICAL ASSOCIATES, INC.