7501 EVERGREEN WAY 2016-01-01 MF Import

( DWR CONSULTANTS, Inc., Geofechnical lnvesfigation Proposed Safeway Gasoline 5(ation, June 8, 2000 1,000,000 psf. As some of lhe native gravel contains large particles, it may be required that loose gravel, disturbed during the excavation process, be replaced with a 3/4 inch minus crushed gravel for the top 6 inches or so to enhance proper compaction. 3. An allowable passive pressure against sides of foundalion components of 400 psf per foot of depth may be used for design. Pour the foundations "neat" against the adjacent soil or provide compacted backfill in the void to fully mobilize the passive resistance. We recommend using a hoe-pack, with the generous addition of water, for compaction. Take care to ensure �he foundation walls are adequately braced to resist the compaction process. Assume the friction between the foundation base and underlying soil at 40% of the dead load. 4. For seismic design considerations, U.C. Earthquake guidance contains a siaiic force procedure and a dynamic iorce procedure for design base shear calculations. I suggest using a spectral acceleration of 0.2 g spectra for soil type 3(fig. 16-3, 199� U.C. Code). 5. The site location in "zone 26" of the U.B.C. Seismic Zone Map and the character of the soils, provides minimal opportunity for liquefaction. 6. Slab-on-grade floors may be supported on re-compacted fiil materials free of debris and foreign material. Provide a iirm and stable sub-grade. Over excavate and replace loose and yielding soils such as wet or very moist silt. We recommend that all floor slabs be founded on at least 6 inches of compacied, crushed gravel. If the gravel is founded on the silt layer, we recommend installing a separation barrier of an inexpensive, non-woven geotextile such as AMOCO 4535 to prevent migration of the gravel into the silt layer. This is not necessary if the gravel is founded on naiive or fill gravel. For compaction, a stiffness of 30,000 Ibs.Cn. or a density of 92% of Modified Proctor Dry density is sufficient. 6.3 Pavements The adequacy of the site pavements responds to the adequacy of the sub-grade. If native soil is to be used for till under the pavement sections, lhe sand shouid be placed in maximum lifts of 8 inches and the gravel in maximum lifts ot 12 inches. All pavement areas should be "proof rolled," in the presence of the Geotechnical Engineer with a fully Ioaded 10 cu. yd. dump truck. We recommend ihe following pavement sections: Page 8 of 11