711 112TH ST SE 7 ELEVEN Geotech Report 2018-01-02 MF Import

Subtrrrface Ezp(aration and Prapored 7-E7even Properry Geotechnical Engincering Report Evcrerr, WashinRfa� DesiRn Recommendarians After removing any unsuitablc fill to thc satisfaction of the geotechnical engineer, the upper 12 inches of the subgrade should be recompacted to atleast 90 percent of the modified Proctor maximum density as defined by ASTM:D 1557. Strucmral fill is defined as non-organic soil, acceptable to the geotechnical engineer, placed in maximum 8-inch loose, horizontal lifts, with each lift being compacted to at least 95 percent of the modified Proctor maximum density using ASTM:D 1557 as the standard. The top of the compacted fill should extend horizontally outward a minimum distance of 3 feet beyond any structure or pavement edge before sloping down no steeper than 2H:1V (Horizontal:Vertical). The contractor should note that Associated Earth Sciences, ?nc. (AES[) must evaluate any proposed fill soils prior to their use ir. fills. This would require that we have a sample of the material 48 hours in advance of filling activities to perfortn a Proctor test and determine its field compaction standard. Soils in which the amount oF fine-grained material (smaller than the No. 200 sieve) is greater than ap�roximately 5 percent (measured on the minus No. 4 sievc size) should be considered moisture-sensitive. Use of moisture-sensitive soil in structural fills should be limited to favorable dry wcather conditions. The on-site soils generally contained significant amounts of fine-grained material and are considered moisture-sensitive. Construction equipment traversing the sire when the soils are wet can cause considerable disturbance. If proper compaction cannot be obtained, a select, import material consisting of a cican, free-draining gravel and/or sand should be used. Free-draining fill consists of non- organic soil with the amount of fine-grained material (less than the No. 200 sieve size) limited to 5 percent by wcight when measured on the minus No. 4 sieve fraction. We recommend a maximum, loose lift thickness of approximately 1 foot, depending on the type of compactor used. A represemative from our firm should inspect any overexcavared areas and be present during placement of structural fill to observe d�e work and perform a representative number of in- place density rests. In this way, A�e adequacy of the earthwork may be evaluated as filling progresses and any problem areas may be corrected at that time. 9.0 FOUNDATION DBSIGN PARAMGTERS Since the on-sire soil conditions are variable, several faundation support options consisting of rock- or CDr-filled tmnches, drillcd picrs, and small diamcter piles are provided. Gach is discussed in ;nurc dctail bclo�v. .t�a,�n iv, zau----- .as:;UCI,iTF.DF.iRINSCf6.\'CES SNfLllp. A'F7M1Y,Iq1/ �O i14P'.,�U.lq - N7A' PB�C H C�