11632 EVERGREEN WAY BASE FILE 2018-01-01 MF Import

Proposed Retail Development J-1443 l 12th Street and Hwy.99 February 26,2004 I � Everett,Washington Page 17 I structural fill, we recommend that all foundations be designed for the structural fill conditions, even though some foundations will be supported on dense native soils. Continuous or colwnn footings cast atop suitable native soils or sWctural sill pads compacted to a minimum of 95 percent of the modified Proctor maximum dry density may be dcsigned for a maximum allowabie, net, bearing pressure of 2,000 psf. A one-third increase of i the bearing pressure may be used for short-te�n dynamic loacis such as wind and seismic forces. Either cast-in-place concrete or masonry block stem walls are considered suitable. Hase friction and carth pressure recommendarions are preser.ted in the Retaining Wall section of this report. � Some unsuitable bearing soils consisting of loose undocumented material, fill wiGti I substantial amounts of deleterious materials,and compressible peat wili lx;encounzered within the � proposed building pad. These materials should be removed to suitable nafive soil and Ute i resulring excavations should be brought back up to grade with curnpacted structural fill. The overexcavation should also extend laterally away from the base of the overexcavation a distance I equal to the depth of the overexcavation or a minimum of 10 ouuide the building pad,whichcver � is greatest,and be backfilled with compacted shuctural fill. I Shallow, conrinuous and interior spread footings should be a minimum of 18 and 24 '�� inches wide, respectively. According to local codes, foundations should be designed with a minimum embedment depth of 18 inches bclow the lowest adjacent finished exterior grad^ tbr frost protec6on. We recommend that interior footings be placed at least 12 inches below finished � � subgrade elevations. All footings must be protected against weather damage both during and after construction, and must be supported by suitable bearing materials as recommended herein. Foundation settlement is oftentimes the function of the condition of the footing excava6on subgrade. Footing excavations should be free of loose or soft soil, slough,debris or water pric;to pouring concrete. If disturbed or soR soils are left beneath the footing azea prior to concrete placement, future settlements may be greatly increased. For that reason, we recommend that the footing sub�rade soils be observed by a qualificd geotechnical engineer prior to pouring footing concrele to document that the condition of the bearing soils is consistent with lhe recommendations contained in this report. ProviJcd the foundation bearing soils aze prepazed as rccommended and the foundations 3re supported on thc recommendcd bearing soils, we estimate that settlements will be within the tolerances spccified. If possible, we recommend that the foundation elements be placed within the samc soil type to minimize the magnitude of possible differential settlemcnt. It should be notcd that dif�erential settlement could approach the total settlement values if adjacent footings are founded on different bearing strata. Floor Slab Desipn Parameters Slab-on-grade floor subgrades should be prepared in accordance with the previous site ' preparation recommendations. In out opinion, t6e loose native soils exposed a&er gading is complzted will not suitable for floor slab suppoct. We anticipate that loose soils will be limited in j extent to the area of transilion bctween thc cut and fill portions of the pad. We recommend that J-1443,022G04 � \-1 , I