3716 UPLAND AVE 2018-03-27 - Laserfiche WebLink

B e 44444444, e an G E CJ TECH13256 Northeast 20th Street,Suite 16 !Cl Bellevue,Washington 98005 CONSULTANTS, INC. �-1 Y (425)747-5618 FAX(425)747-8561 March 30, 2015 JN 15044 Jesse Jerabek 3716 Upland Drive Everett,Washington 98203 Subject: Geotechnical Engineering Study—Foundation Bearing and Slope Concerns Proposed Residence 3716 Upland Drive Everett, Washington Dear Mr. Jerabek via email The undersigned associate visited the subject site on February 5, 2015. The purpose of this visit was to observe the existing site conditions, excavate some shallow hand auger holes, and to develop opinions regarding the slope and the new house that will be constructed on the subject site. The recommendations and conclusions presented in this report are professional opinions based on the visual observations made during our site visit and on previous experience with similar projects. We excavated shallow hand auger test holes during our visit, but no deep subsurface explorations were conducted for our work. We were provided with plans developed by American Home Planners and dated December 15, 2014. Based on this plan and discussions with you, we understand that a new, two-story house with a basement on its eastern end will be constructed in the general footprint of the existing house. The western end of the new house will have a crawlspace and will approach within approximately 40 feet of the top of the western steep slope. If the scope of the project changes from what we have described above, we should be provided with revised plans in order to determine if modifications to the recommendations and conclusions of this report are warranted. The southwestern wall of the new house will be located about 40 feet from the crest of a steep slope that extends down to a ravine. This slope is moderate to steep and appears to be on the order of 80 feet tall. The slope is well vegetated with trees, grass, and black berry vines. No evidence of large-scale slope instability was observed, though we did observe some indications of shallow soil creep. Also, there was a skin slide scar on the opposite side of the ravine visible during our visit. The remainder of the lot is essentially flat. Neighboring properties to the north and south are also residential and are generally slightly below and above the subject property, respectively. Our understanding of the subsurface conditions at the site is based on the observations made during our recent site visit and on experience gained from other projects in the site vicinity. During our visit, we excavated three shallow hand auger test holes in the back and side yard (See Plate 2). The first test hole (northwest corner of house)was located approximately 40 feet from the top of the slope and-revealed 2 feet of loose fill overlying 6 inches of remnant topsoil over loose reddish-brown slightly silty sand that became loose to medium-dense at 3 feet, and wet at 3.5 feet. Underlying the sand, we encountered gray, cemented, very dense, silty sand with gravel. This glacially compressed cemented soil is commonly referred to as glacial till. The second (western) hole was near the crest of the steep slope, and this hole revealed 3 feet of loose fill and topsoil overlying loose to medium-dense slightly silty sand which in turn at 5 feet was underlain by very dense, gray, glacial till. Our third hole was located to the northeast of the existing house and revealed loose fill and weathered silty sands to 3 feet,where we encountered very dense glacial till. All of the hand auger holes were terminated due to auger refusal in the till(Detailed Logs Plate 3). GEOTECH CONSULTANTS,INC.