2222 LOWER NORTON AVE 2018-01-01 MF Import

The alluvial sand cfeposits below the fill layer can be characterized as having relatively high strength and low cornpressibiliry, becoming generally stronger and less compressible with depth. iu 4.3 GROUNDWA'TER CONDITIONS t� I;� �� I? Grouudwater was measured at the time of the currem explorations at depths ranging from about 5 to 7 feet below ef:isting site grades. We understand that this groundwater level is generally consistent wich previously measured levels at other areas of the mill. Groundwater levels may fluctuate due to factors such as tide-level changes in the nearby Port Gar�ner T3ay and seasonal changes in precipitalion. �. 4.4 LIQUEFACTT��N pnT�NTIAL a Liquefaction is a ph�.nomenon wherein saturated soils suffer a]oss of internal shear strength when subjected to cyclical loading that is charact�ristic of earthquake induced ground shaking. Documented conditions indicate that a]iquefiable soil will likely be a snturate�, very loose to medium dense, fine- to medium-grained sand with a very :ow fines con[ent. S.ince portions of , the hydrau]ic sand fil] layer appear to meet this general criterion, there appears to be a potential for liquefaction to occur during a major earthquake. Possible consequences of Iiquefaction for pile foundation supperrt of the planned facility are briefly discussed in subsection 6.1.3 below. t i� i: f :� �;, The scope of this investigation did r.ot include a specific liquefaction assessment and eval,ation of this risk. We would be pleased to assist you with any further evaluation, as requested. 5.0 CONCLUSIONS The Converting Plant Addition can be supported on conventional augercast pile Poundations. Our analyses indica[e that 18-inch diameter augercast piles, installed to an embedment depth of � at least 50 feet below present site grades, can be designed for allowable axial compressive capacities of up to 100-tons each. E: t� Our analyses indicate that 18-inch diameter sugercast piles will experience about 1/2-inch of pile head deflection under an applied static ]ateral load at the cap of 1Q-tons per pile. As discussed in subsection 4.4 above, the hydraulic sand fill layer covering the site may be subject eo a significant loss of strength during a major earthquake. Unless a liquefaction analysis is undertaken, we suggest that lateral capacities of 18-inch diameter augercast piles be reduced by about 50 percent for earthquake loading. The remaining sections of this report present our geotechnical recommendations pertaiiung to design and constructian of pile foundations. I h:F � 503289-01.01 li t� January 19, 1995 DA\fES & b{ppR�