4704 HARBOR LN 2018-01-02 MF Import

From NELSON GEOTECHNICAL ASSOCIATES, INC 17311 135TH Ave. NE #A-500 11/20/2009 14:09 #243 P.008/011 FIELD REPORT Project: Anderson Property File No.: 816909 Owner: Location: Weather: Woodinville, WA 98072 Purpose of (425) 486-1669 FAX 481-2510 Visit: Rick and Holly Anderson Date: 09/13/09 Everett, Washington Report No: 3 Rainy, Cloudy, partly Sunny, Page: 1 of 4 40's Wall Installation Monitoring By: BD We visited the site today at the request of Rick and Holly Anderson to observe the installation of a soldier pile retaining wall along the top of the existing steep north -facing slope adjacent to their existing residence and pool. Upon arrival, we observed that steel plates had been placed behind the piles that were set yesterday. These are temporary and will be removed after the lagging has been placed. After a short rain shower when the contractors covered the site to prevent the disturbance of the existing subgrade, we observed the installation of 4 piles (N6 through N9) as shown on the Site Plan. Each hole was augured with a 24- inch auger to approximately one foot below the planned bottom of pile elevation. The soil that was exposed during the excavation consisted of brown -gray, fine to medium sand with silt to silty fine to medium. sand. We did not observe sloughing in the holes after they were drilled, and we did not observe evidence of groundwater. All the holes were backfilled today with CDF and the top of the piles were set at an elevation of 190 feet +/- 0.1 inches. We also observed that the contractor began placing the lagging between piles N16 to N15 and N15 to N 14. The lagging consisted of 6 inch by 6 inch treated timber lagging. We observed that the contractor placed a nail between each lagging board to allow for. proper drainage, as indicated on the project plans. The contractor has been able to stay approximately three to six feet away from the wall with the large drilling machine. However, as the machine works its way to the west, towards the pool and hot tub area, the machine will be approximately 12 inches or less away from the back of the piles. The wall was not designed to hold the weight of large equipment, and the wall will not be totally stable until all of the tiebacks are installed. Also, there is a safety concern for the equipment and operator. It is extremely important to not overload the beams and cause distress to the wall. If it is determined that the wall could potentially be damaged due to the proximity of the large equipment, we will recommend the removal of the hot tub to allow additional room for equipment access. We discussed this with Jason and he agreed that the limits of access have been reached, if not exceeded, and will inform us immediately if he decides that the wall or his workers are at risk. We recommend that no material be removed from the front of the wall until all of the piles have been installed. Attachment. Site plan + wall profile Signe - Z19N Distribution: