10105 19TH AVE SE Geotech Report 2018-01-02 MF Import (2)

� � KA No. 092-06160 Octobcr25. 2000 �e 4 during lhe summcr months). If the soils cannot bc dried back to a workabfe moisturc condition,remedial measures may be rcquired. General project site w�interi2ation should consist of the placement of aggregate base and the protection of cxposed soils during the construction phas^.. It sheuld be understood that even if I3est Managcmcnt Practices (BMP's) for wintertime soil protection are implcmcnted and followed,there is a significant chancc that soil mitigation work will still be required. Any buricd structuces ercountered during construction should be propedy removed and backfilled. Excavations, dcpressions, or soR and pliant arcas cxtending below the planned finish subgrade Ievels should be cicancd io firm imdisturbed soil, and backfilled with structural fill. In gcneral, any septic tanks, underground sroragc tanks, debris pits, cesspeols, or similar structures sLould be completcly removed. Concrete footings should bc removed to an equivalent depth of at least 3 feet below proposed footing elevations or as recommended by tl�c gcotechnical engineec Thc resulting excavations should be backGllcd with structural fill. A representative of our finn should bc present during all site cicaring and grading operations to test and obscrve earihwork construction. This tcsting and observation is an intcgral part o; our service, as acccptanca of eartl�work construction is dcpcndcnt upon compaction and stability of the material. "Che gcotechnical engineer may reject any material that does no[meet compaction and stability requirements. furthcr itcommcndations, contained in this rcport, arc prcdicated upon the assumption that eanhwork constniction will conform to the recommendations scl forth in tliis section and in the Structural Fill Section. Tem porar�Ex cavet i on s 1'hc on sitc glaci�l soils have variablc cohesion strcngtlts, thcrefore Qie safe anglcs to which thcse materials may bc cut for tcmporary excavations is limitcd,as the soils may be prone to caving and slope failures in temporary excavations deeper than 4 fcet. Temporary excavations in thc medium dcnsc glncial soils should bc sloped no stceper than I II:1 V (horizontal to vertical) wherc room permits. Temporary cxcavalions in the dense to very densc glacial soils should be sloped no stccper than 3/4H:1 V (hori�ontal to vcrtical) wherc roo�n permits. If thc soil in il�e excavation is subject to vibration from heavy traCfic, thc tcmporary excavation should bc slopcd no steeper than 1%:H:l V. All tcmporary cuts sl;ould bc in accordance with Washington Administrativc Code (WAC) Part N, Excavation, "frcnclting, and Shoring. The temporary slope cuts should bc visually inspected daily by a qualificd person during construction work activities and the results of thc inspections should bc includcd in daily reports. The conVactor is responsible for maintaining the staUiliry of the temporary cut slopcs and minimizing slope crosion during construction. The temporary cut slopes should be covercd with visqucen to help minimizc crosion during wet weaUier and thc slopcs should be closely monitored until the perntanent retaining syslcros are complete. Matcrials should not be stored and equipment operatcd within 10 feet of the top of any tcmporary cut slope. A ICrazan & Associa[es gcologist or gcotcchnical engineer should observe, at lcast periodically, the tcmporary cut slopes during tlie excavation work. The reasoning for this is that all soil conditions may not be fully dclincatcd during the previous gcotcchnical exploratory work. In thc case of temporary slope cuts, the cxisting soil cottditions r�iay not be fully revealed until the excavation work exposes the soil. Typically, as cxcavation work progresses the maximum inclination of the temporary slope will need to be recvaluatcd by thc gco[echnical engineer so that supplemental recommendations can be madc. Krnzen&Assocfeles,Inc. Y Officcs Scrving The Wcstem United States rI I 1V1