4920 EVERGREEN WAY STAPLES Geotech Report 2022-10-25

GEOTECHNICAL ENGINEERING REPORT Staples Rockery Failure Everett, Washington Terracon Project No. 81175122 March 8, 2019 1.0 INTRODUCTION Terracon Consultants, Inc. (Terracon) is pleased to present the results of our geotechnical engineering services for the proposed project. The site is located at 4920 Evergreen Way as shown on the Site Location Map, Exhibit A-1. Terracon's geotechnical scope of services included the advancement of a soil boring atop the rockery between Glacier Lane and the west side of the Staples building. The boring was advanced to 56'/2 feet below ground surface (bgs). The boring log is included in Appendix A. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: subsurface soil conditions geologic hazards groundwater conditions lateral earth pressures earthwork retaining walls Through discussions with the property tenant, Staples, Inc., we understand there is a desire to replace the rockery with a retaining wall for only the northern half of the building wall. For purposes of this report, design recommendations for the proposed retaining wall design are focused on the northern half of the rockery, which includes the failed section of rockery. A meeting with the City of Everett was held to discuss the feasibility of several retaining wall options. The City indicated they would be willing to permit a permanent easement for retaining wall construction within the City right-of-way. Therefore, the recommendations presented herein are based on an assumed retaining wall design for soldier pile and tieback system. 2.0 PROJECT INFORMATION 2.1 Site Location and Description Item Description The project is located just west of the building located at 4920 Evergreen Way in Everett,Washington along the east side of Glacier Lane. Site Location Latitude: 47.952000° Longitude: -122.215784° Responsive • Resourceful • Reliable 1