1011 39TH ST 2016-01-01 MF Import

I GEOTECHNICAL ENGINEERING STUDY Susan and Tfiomas Zakos E-1Q138 August 20, 2002 pa�� 3 A re!atively level c�rass area extends to the north of the existing residence out to an existing four to six foot high railroad t�e retaining v��all constructed within ihe descending slope. The retaining wall supports a fill zone that creates a relatively level yard area along the north side of the residence. The base of the wall is bounded to the north by an ��PProximately four to six foot wide relatively level bench area. The slope then descends steeply frorn the northem edge of the bench lo tl-.e centerlinc of the undeveloped road easemenl at yradients on :he order of 65 to .�i5 percent. Subsurface Conditions Subsurface conditions wit'iin the vicinity cf the wall �roere evaluated by drilline� four bo;ings to a maximurn depth of twenty-one and one half (21 .5) feet below existing grade. Please refer to the Boring Loys, Plates A2 through A8, for a more detailed description o( the conditions encountered at each location explored. A description of the field exploration methods is included in P.ppendix A. The followirg is a generalized description of the su�s�nfdce wn�iliui�s encuunlere�. At our boring locations, we encountered three and one half to eig!it ieet of very loose to loose (ill. Tlie fill is cornprised primarily of silty sanci (Uni(ieci Soil Classification, SM) witii localized zones of poorly graded sand with silt (SP-SM). At the base of the wall in Boring B-2 we encountered up to two feet of debris laden fill. Partially exposed blocks of concrete, brick, and miscellaneous household debris are exposed in the face of the slope downslope from the face of the wall. The fill was characterized by its disturbed appearance, very loose to loose consistency, and the presence of localized areas of abundant debris. The underlyir.y native soils at our boring locations were comprised primarily of interbedded sequences of poorly graded sand with silt (SP-SM1, poorly c�raded sand (SP), and silty sand (SMI to the maximum exploration depth of twenty•one and one half (21 .5) feet below c�rade. In Borinc� E-1 , we encountered a six inch thick layer of sandy silt at twenty (20) feet belc�v grade. The upper one and one half to three and one half feet of rative soil at our borin� locations was loose to medium dense becoming dense to very dense to the maximum exploration depth. The native soils are defin�d as advance outwash deposits (Map Unit Qva) on a 1985 United States Geological Survey map of tl�e Everett �uadrangle. __,:��n c��„�,�:i;.�:�;�:. i,,,: C; (4�1 � Z 4L] . � . .5"aW y Mr�A. � ��R�y r ��.•��il � . �. � ' � . ♦ ,. �' ::: � . .. . . " ` . . .+�"..:�ti . �,r. . . .. . . . ' . �.. ..�:..i` . �_