3210 36TH PL NE 2018-01-02 MF Import

i sutt comprestiiblc silt and achieve suitablc embedment in the underlying s�nd la��cr. Piks should not extcnd �leeper than GO Iect below propescd linal site grades (Glevation 11� fcet) to a�•oi�l loss of Uearing capacity in the dceper fine-grained soil deposits. Recommended allowable axial pile capacities for l8-inch diameter piles are presented in Table 1 for various pile tip elevations. Thcse estima[es assume that the pile supported strucmres will be preloaded as previously discussed prior to installing piles to minimize downdrag loads and that finished site grade is at about Elevation 15 fcet. Downdrag due to setdement of the upper organic sil[ layer has bcen taken into account in the axial load capacity of thc augcrcast pilcs. Table 1. Axial Pile Capacities Augercast Pile Embedmant Augarcast Pilo Allowa6lo Pile Capacity(kips) Diametar gelow Final Site Tip Elevation (inches) Grade(fnot) (feet) Compression Uplift 40 -25 20 50 � ------.—......_.. — -- �----- - ----. _.— --- '�, 18 50 -35 60 75 --------- ----.........---- _. ._.. _ _— . _.--._ 60 -45 100 110 � �� Allo�vable pile capacities are provided for Alfowable Stress Design (ASD) and the allowable capacitics are ior comUined dcad plus long term live loads and may be incrcascd by one-third when considerinc I desibm loads oi short duration such as seismic forces. The allo��able capacities are based on the strength of die supporting soils for the depths below the existing ground surface and include a facror of safety oC diree for end bearing and t�co for shaft friction. The capacities npply ro single piles. If piles are spaced at least thme pilc diameters on center, as recommendcd, no reduction for group action is needed. The structural characteristics of pile materials and structural connections may impose limitations on pile capacitics and shoidd be caaluated by the strucwral enginecr. Por example, steel reinforcing �aill bc I� needcd for augerc�st piles �ubjected to uplitt or largc bcnding moments. i Lateral Capacities I Lateral loads can bc resistcd Uy the skin Gictiun and p�ssice soil prusurc on the nrtical piles and by th� � passivc soil pressures on pile caps. Because of the potential separation Uctwecn the pile-supported foundation components and the underlying soil lram settlement, base Iriction on pilecaps should not be includcd in calcula[ians for lateral capacity. �Ve analyzcd the ultimate lateral load capacity of 1S-inch augercas[ piles with the pile head fixed against rotation and under Gee liead conditions agains[ rotation. Ne evaluated the lateral capacity for '/,-inch, '/-inch, and 1-inch deflection at the top of the pilc. The results of our analyses are summarized in Table 2 and the results represent ultimate values and do not include a factor of safery. �Ve recommend that the passive resistance for the portion of die pile cap located above die groundwater table be estimated using an equivalent tluid density of 4�0 pounds per cubic tbot where the soil adjacent to the foundation consists of compacted structural fill. We anticipate that the structural fill placcd around dic pilecap will be above the water table. This passi��c resistance valucs^�sume a 5-foot thick pilecap and z minimum lateral deflection of'/,-inch. If the actual pilecap thickiies� is greater than 5 feet or if lateral dcflections arc less ,han '/�-inch, these passive resistance values may b • unconservative and we should be contacted to provide re��iscd values. 1'he passive resistance value presented aUove represent an ultimare value and docs not include a factor of safety. I Ff1r;\'u ,P'i,S7-OOJ-0O Fage�J GEOENGINEEp� n�,�.i.�� i�.,nn� — — ---- _. ._-- -- -.,....,. �" � _ .. m_ .�_. :�. �„ _ . _ . �,. _ . _ _ _... _ __._ x �:�. __ .v,;