1600 MADISON ST 2016-01-01 MF Import

Mr. Chris Lark Fe6ruary 20, 2001 BaseJ on the measured standard penetration resistance values, the on-site soils aze sufficiently dense that the potential for earthquake induced soil liquefaction is considered to be very low. In addition, based on existing information, the site is not underlain by any known active fault. Therefore, ground rupture from faulting and liquefaction aze not design considerations for this project. 5.2 FOOTINGS Conventional spread footings bearing directly on the underlying glacial till or a structural fill extending to the till aze recommended for the support of the new fire station. T'he footings should be designed based on a maximum allowable beazing pressure of 3,U00 psf that may be incr�ased by 1/3 for uansient conditions such as wind and seismic loadings. All exterior footings should be founded a minimum distance of 18 inches below the adiacent finished grade, and all interior footings should be at least 12 inches below the top of floor slab. Lateral forc;es resulting from wind or seismic e��ents :nay be resisted by a co�nbination of sliding resistance at the footing base and passive earth pressure against the buried portions of the structure. A coefficient of friction of 0.5 may be assumed between the base of the footings and the bearing surface. Passive soil resistance against the sides of buried footings can be estimated using an equivalent fluid unit weight of 500 pounds per cubic foot (pct) assuming that the backfill against the footings coiisists of granulaz structural fill compacted to 95 perccnt of the materiai's mauimum dry density, determined :�sing ASTM D1557 (Modified proctor). The recommended passive resistance includes a factor of safety of about 1.5. All footing excavations should be trimmed neat and the bottom of the excavation should be cazefully prepared. The footing excavations should be observed by an engineer from our fian prior to placing steel an3 concrete, to verify that the tecommendations of this report have been followed, and that an approp;iate bearing stratum has been exposed. Total and differentiai settlements of footings designed and constructed in accordance with our recortunendations aze anticipated to be within tolerable limits. Under static loading, we estimate that the spread footings may experienGe total settlements of less than about %2 inch. Differential settlements between twa adjacent load-bear:ng components supported on competeni soils aze expected to be less than about Y, inch. 5.3 CONCRETE SLAB-ON-GRADE Interior slab-on-grade floors should be provided with an adequate moisture break. The capillary break should consist of a minimum of 6 inches of free-draining, crushed rock or well-graded sand and gravel which is compacted to a firnt and unyielding condition. We recommend that the capillary break material have a maximum particle size of'/. inch, with no more than 80 percent passing the No. 4 sieve and less than 5 percent passing the U.S. Standazd No. 100 sieve. In areas � r � �� � � � � � � � � � � 00-046-100 Geotech Report 4 PanGEO, Inc. �