3000 ROCKEFELLER AVE SEPA 017 - 012, SPU 17 - 012 & REV 17 - 021 - COURTHOUSE ADDITION Geotech Report 2025-04-16

GEOTECHNICAL ENGINEERING DATA REPORT SNOHOMISH COUNTY JUSTICE CENTER EVERETT, WASHINGTON 1.0 INTRODUCTION This report presents the results of our geotechnical subsurface investigation and laboratory testing for the proposed new courthouse at the Snohomish County Justice Center in Everett, Washington. Specifically,this report presents the results of Task 1 -Geotechnical Explorations and Laboratory Testing phase of the project, which is part of the Schematic Design (SD)Services portion of our work. 1.1 Site and Project Description The project site is located at the Snohomish County Justice Center campus in Everett, Washington, shown on the Vicinity Map (Figure 1). The new courthouse building will be located in the courtyard north of the existing courthouse as shown on the Site and Exploration Plan (Figure 2). The new building will be bounded by Wetmore Avenue on the west, Wall Street on the north, the projection of Rockefeller Avenue on the east, and the existing courthouse on the ( south. We understand the project will extend up to the city street right-of-way on the east,west, and north sides, and that those three sides of the excavation will require structural shoring. We understand the planned depth of the excavation will be approximately 12 feet below existing grade on the east side and approximately 2 feet below existing grade on the west side of the site. These depths are based on an anticipated floor elevation of 142 to 145 feet across the site. Figure 3 depicts a subsurface cross section around the perimeter of the site. The new courthouse building site is the courtyard of the existing courthouse building. The courtyard consists of a combination of level concrete paved areas connected by stairways and landscaped areas that include short retaining walls. The site grade drops in elevation from 155 feet at the east side of the courtyard to elevation 140 feet at the west side. We also understand that re-routing or extending an existing cut-and-cover pedestrian tunnel connecting the courthouse with the jail facility at the basement level may be necessary. Hart Crowser Page 1 17960-00 June 17,2013