1920 GRAND AVE Geotech Report 2022-10-25

Mr. Bill Messner ES-6132 October 5, 2018 Page 5 The allowable anchor pullout values provided above apply to typical six-inch-diameter tieback anchors that will have the capacity to be post-grouted after installation. Tieback anchors should be verification tested and proof tested in general accordance with the most recent edition of the Recommendations for Prestressed Rock and Soil Anchors manual, published by the Post- Tensioning Institute. A minimum of two verification tests (200 percent of the design load) should be performed. Verification test anchors may be used as production anchors provided anchor testing is acceptable. Production anchors should be proof tested to 130 percent of the design load. A representative of ESNW should observe the anchor testing and provide documentation of the test results, which should include an elevation of anchor creep susceptibility. Tieback anchors should be locked off at 90 to 100 percent of the design load. The soldier pile end bearing capacity value provided in this section is based on the soldier piles embedding at least 10 feet into dense native soil. Geotechnical Plan Review We reviewed the referenced shoring plans prepared by CG Engineering, including the structural calculations. Based on our review, the plans conform to our geotechnical recommendations, including both our previous recommendations and those provided in this letter. Additional Services ESNW should be consulted to review final site designs and/or project plans to ensure appropriate geotechnical provisions have been incorporated. ESNW should also be retained to provide testing and consultation services during construction. The services described in this letter were prepared under the responsible charge of Raymond Coglas, P.E., who is a licensed engineer(with geotechnical expertise) in the State of Washington. It is noted EMC Title 19 defines "geologist" but does not define "engineer". Raymond Coglas, P.E., understands the requirements of the current geologically hazardous areas chapter, EMC 19.37.080, and the definitions of the applicable terms contained within EMC 19.4. Individuals under the responsible charge of Raymond Coglas, P.E., have prepared this geotechnical evaluation, reviewed the previously completed ECI field investigation, and researched historic records on or in the vicinity of the subject site. In our opinion, the scope of services completed for this project is adequate to meet City requirements. We have concluded the proposal will avoid impacts to the geologically hazardous area, and no geological hazards will result from the proposed development either on site or on any adjacent properties. Earth Solutions NW,LLC