307 80TH PL SW 2018-01-16 - Laserfiche WebLink

s . • �11 � } G E O T E C H 13256 Northelst 20th Street,Suite 16 � Be(levue,Wlshington 98005 CONSULTANTS, INC. (�25)747-5618 FAX(425)747-8561 j � July 3�, 2012 � i JN 12233 ! Dennis Colyn � 4601 —21st Drive West ; Everett, Washington 98203 via email to: dennis.colyn@yahoo,com ' Subject: Geotechnica! �ngineering Considerations i Residence Addition Project � 307 - 80th Place 5outhwest i Everett, Washington i Dear Mr. Colyn: � On July 20, 2012, the undersigned Principal of Geotech Gonsultants, Inc. met with you at the ; subject residence in Evaret#. Based on plans we received and conversations with you, we i understand that an addition is proposed on the western side of the residence, and a basement i addition is proposed beneath the existing western portion of the residence where a deep crawl spaced now exists. The foundation in a porfion of the crawl �pace is to be lowered because of the depth of the propased basement slab. The purpose of fhis visit was to observe the existing site canditiQns in the area of Yhe new addition, observe the soii conditions in some test holes, and subsequently develop opinions regarding the geotechnical engineering aspects of the project. The recornmendations and eonclusions presented in this report are professional opinions based on the visual observ�tions made during our site visit, and on previous experience with other projects in the � Puget Sound area. i SIT� COND[TIOPIS The residential property is located north of the cui-de-sac of 80th Place Southwesfi. The residence is located on the eastern portion of the property. There is a smafl y�rd west of the existing residence and a forested area is located west of that. Based on our observations, it appears that fhe inclination of the property within at feast 50 feet of the residence is approximately 20 to 30 percent. We did not observe any indications of soil instability of the slope. ' i A large crawl space is located under the western sidE of the residence. It is apparent that, based - on our observations, the residence is founded on conventional footings buried abaut 2 feet below the existing, outside ground surface. The footingslfoundation appears to be in a very sfabie condition in the crawispace area. Based on #est holes excavated inside and outside of the crawl space, it is very apparenfi that the native site soil is giacial tiil comprised of graveily silty sand. 7his ls also the soif nafed in the area on a published Geology map (ivtinard, 1985}. The glaciai tiil is mostly medium-dense within abou# 1 foot of the native ground surface, then becomes very dense at approximately 3 to 4 feet. CONCLUSIONS AND RECOMMENDATIONS �I i As noted above, glacial till soil that is mostly medium-dense is located near the surface. This soil becomes very dense about to 4 feet below the native ground surface; this soil has a very high she�r strength and is desirable in the Puget Snund Region from a slope stabilify standpoint. The .i i ; GEOTECH CONSULTANTS,INC. i;