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

Proposed Retail Development J-1443 112'�Street and Hwy.99 February 26,2004 � Everett,Washington Page 18 the upper 12 inches of exposed soil Se removed and the underlying soils compacted to a minimum of 95 percent of the modified Proctor maximum dry density. T'he stripped soils co,�id then be moisture conditioned and placed as shvctural fill anywhere on site provided it is also cor.ipacted to a minimum of 95 perccnt of �he modified Proctor maximum dry density. �'or on-site soils compacted to 95 perccnt of the niodified Procror maximum dry density, �•�e have estimated a ver[ical modulus of subgrade reacdon af 200 pounds per cubic inch,based upon a correlation with the California Bearing Ratio test results. We understand tt�at the exposed conerete sl.�-on-grade floor will be 4 to SY� inches thick. The floor slab should be underlain by a layer of granular aggregate consisting of 2 inches of fine aggregate base over 4 inchcs of coarse aggregate base. We recommend that the fine aggregate base be underlain by a 6-inch thick layer of coarsc aggregate base.The Snc aggregate base should consist of confom�with the gradation requirements of ASTM D-448, grading No. 10,with 6 to 12 percent passing the U.S. No. 200 sieve while the course aggregate base should conform with the gradation requirements of ASTM D-448, grading No. 57 or No.67. With the recommended site preparation and monitoring, the differential setUcment of the floor slab constructed as recommendcd is estimated to be less than 0.9 inch in 40 feet and 0.5 inch between the exterior walls and adjacent floor slab. Drainage Considerations � A perimcter foundation drainage system is recommended around the building bccause of the occurrence of glacial till in the building pad azea. Drains arc also recommended behind all retaining walls. Aiternatively,retaining walls could be drained with weep holes on a maximum 8- foot horizontal spacing. Retaining wall drainege syslems should be slopcd to drain by gravity to a storm sewer or other suitable dischazgc location. Water &om downspouts and surfacc water should be independently collected and routed to a storm sewer. Additionally,we recommend t6at the finished grades around thc building be designed to route surface water away from the building Pinal exterior grades should promote free and positive drainage from the building azeas at all times. Water must not be allowed to pond or to collect adjacent to foundafions or within the immediate building arca. We rccommend that a gradient of at least 3 percent for a minimum distance of 10 fcet from Qie building perimeter be provided, except in paved locations. In pavai areas, a minimum gradient oF one percent should be provided unless provisions are .ncluded for collcction and disposal oFsurface water adjacent to the structure. Retainine Wall Desi� ' Walls may be dcsigned as a "restrained" retaining wall based on "at rest" earth pressure, plus any surcharge on top of the wall as described below, if the wall is attached to the building ' and movement is not acceptable. The wall could also be desi�ned based on "active" earth pressure, if the wall is not part of the building and some movement of the rctaining wall is acceptable. This movement could equa? at least 0.1 percent of the wall height. For active and at- rest earth pressures, we recommend using 35 and 55 pcf, respectively. For those portions of foundations embcdded more than 18 inches below finish sunounding grade,we rccommer,d using J-1443,022604 \$ .