5910 LARIMER RD 2018-01-02 MF Import

Gary A. Flowers, PLLC Geological & Geotechnical Consulting 19532 12te Avenue NE Shoreline, WA 98155-1106 January 15,2007 Project No. 06-128 Mr. Ron VanDerbeken 5910B Larimer Road Everett, WA 98203 Subject: Geotechnical Services Report 5910B Larimer Road, Everett, Washington Dear Mr. VanDerbeken: This letter presents the results of our recent geotechnical inspection of the soldier pile retaining wall that was installed on your property to mitigate an ongoing landslide at the site. The wall was installed without a building permit but with the approval of the city of Everett for an emergency landslide repair. The wall was designed by Joe Lucia, S.E., based on geotechnical design parameters provided by this firm in our Geotechnical Services Report to you dated December 20, 2006. The soldier pile retaining wall was installed by McDowell Northwest. Excavation services were provided by Active Environmental. Mobilization onto the site began on December 27, 2006 and the wall installation was completed on January 4, 2007. A total of 10 piles were installed for the planned 12' high retaining wall. Design depth for the piles was 26 feet below grade. Steel beams were to be W 18x76 with 20' embedment, a 30" shaft diameter and 8' spacing between piles. Nine of the piles are located on the VanDerbeken property and one pile was located on the Keck property (with pcmiission). An additional three piles were to have been installed on the Keck property but were not due to ongoing discussions with the property developer (1-lillcrest Homes) and their insurance company. One additional pile beyond the structural engineering design was added. Design depth of the piles was 26 feet below ground surface. The drilling for pile no. 7 could not penetrate past a depth of 22 feet due to caving conditions. The hole was abandoned and filled with lean mix concrete. After consultation with the structural engineer the pile was moved 2' to the north so the pile spacing would not exceed the design spacing of 8' and was successfully installed to the required depth. Due to the potential for encountering caving conditions at pile location no. 8 the spacing between nos. 7 and 8 was reduced to 6' to allow for a shallower plccment, if required. As a result of the shortening of the pile spacing from 8' to 6' between these three piles it was necessary to add a tenth pile at the south end of the wall. Gary A. Flowers, PLLC. 19532 126 Avenue NI: Shoreline, Washington 98155.1106 206-017-7640