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FOUO(I81t005 <br /> Sprcad footing foundations may bc used for foundation support of thc planned singlc family <br /> residences when foundcd on medium dense, documented swctural fill. An allowablc <br /> foundation bearing capacity of 2000 pounds per squarc foot may be uscd for design of thc <br /> spread footings. A shon term incrcase of one-third may be used for wind,snow, or seismic <br /> loads. Steps in thc foundation grade arc acceptablc provided that none of the foundations are set <br /> to bcar adjacent to Uic slep. A ]I1:I V load line extending down from lhc edge of the foundation <br /> must not daylight a cut slope. Anticipatcd settlemcnt of the foundation when properly set to bcar <br /> on an approved bearing stratum will be Icss than 1 inch. We recommend that Dattemiann <br /> Gcotcchnic:il Consulting, pllc pccform a foundation soil bcaring cvaluation prior to placing <br /> foundation concrctc. <br /> Floor Support <br /> Slab-on-grade concrctc iloors should be cast atop a p�pamd subgrs:le. The subgrade soils <br /> should bc compacted to a minimum of 90 percent oC Ihe modified Proctor maximum dry density <br /> or be firm, non-yielding native sediments. 17�e floor slab should be cast atap a capillary break <br /> consisting of a minimum of 4 inchcs of pea gravcl or clean crushed rock with Icss ehan 5 percent <br /> fines (materia] passing the No.200 sieve). The capillary brealc will reduce the potential for <br /> moisturc Gom wicl:ing through thc floor slab. A plastic shccUng vapor barricr should also be <br /> placed atop U�e capillary 6rcak materi:il. All conerele placement should follow the guidclines <br /> set forih by the American Concrete Institute (ACI). <br /> Drainagc Considcrations <br /> A perimcter foundation drain should bc eslablished to prolect the foundation/mwlspace from <br /> ground waler inwsion. The Icvcl oCthe foundation drain sUould be sct at, or sliglrily bclow, thc <br /> base of the footing elevation. The drain should consist of 4 inch diametcr, rigid, perforated, <br /> PVC drain pipc and should be set to nllow for gravity discharge. '1'he drain pipc should hc <br /> surrounded by a minimum nf 6 inches of pea gnvcl or washed dnin rock.. Roof drains should <br /> not tic into U�e fooling drain but should be c;ollected in a scparate, Uglilline drain. The drains <br /> should be routed to discharge on a rockcd splash pad at the east side of the property wherc <br /> curnnt runo(1'from the site discharges. Tlie rocked splash pad should be a minimum of 4 fect <br /> widc by 6 Icct long by 1 '/: tcct tl�ick. The top of thc pad should hc fltLsh wiili thc ground <br /> surf:�cc and should hc constnictcd usin�, G to 12 inch diamc�cr crushcd mck <br /> Conclusion <br /> I�icld conswction monitoring and observation scrvices should be considcrcd an extension of <br /> this initial geotechnical cvaluation, and are essential to Gre deterniination of compli:uice with thc <br /> projcct drawings and spccitic:ations. Such activitics would incl�dc sitc cicaring a�id grading, <br /> subsurface drainagc, foundntion bearing soil cvaluations, fill placement and compaction. <br /> Our findings and rccommendations provided in this report wcrc pr�pated in accordancc will� <br /> generally acceptcd principles of enginecring geology and gcotcchnica] enginecring as practiced <br /> in thc Puget Sound arca at thc lime this rcport was submitted. Wc maY.c no other w:uranty, <br /> cilhcr cxpresscd or implied. <br /> BGC, pllc 14267 209�'Avenue NE, Woodinville, WA 98077 (425) 273-5062 <br />