5700 23RD DR W 2018-06-28 - Laserfiche WebLink

Geotechnical Report Northshore Christian Church, Building F 5700 — 23rd Drive West Everett, Washington 1.0 PROJECT DESCRIPTION The project consists of developing the site with a 14,134 square-foot classroom building (known as Building F) with a basement level and associated access and utilities. Review of Sheet A 1.2, dated October 27, 2016 indicates the classroom building will be located east of and adjacent to existing Building E. Building F will be a single-story structure framed over a full depth basement. Basement and main floor elevations will be constructed at Elev.416.34 feet and 428.0 feet,respectively. Excavation depths are expected to be between 10 and 15 feet for construction of basement level foundations. A new patio will be constructed north of and adjacent to the building. A retaining wall will be built on the site's northern slopes for support of patio subgrades. The wall will have a maximum height of approximately 12 feet. We expect that the lower level floor will be constructed as a slab-on-grade with wood-framing for the main level. Foundation loads should be light, in the range of 2 to 5 kips per foot for bearing walls and 25 to 75 kips for isolated columns. The recommendations contained in the following sections of this report are based on our understanding of these design features. If actual features vary or changes are made, we should review them in order to modify our recommendations, as required. We should review final design drawings and specifications to verify that our recommendations have been properly interpreted and incorporated into project design. 2.0 SCOPE OF WORK Our work was completed in accordance with our Scope and Fee/Work Authorization proposal dated November 3, 2016. Accordingly, on November 11, 2016, we explored subsurface conditions at the site by excavating 3 test pits to a maximum depth of 13 feet below current site grades. Using the information obtained from our subsurface explorations, previous subsurface explorations, and laboratory test results on soil samples, we performed analyses to develop geotechnical engineering recommendations for project design and construction. Specifically,this report addresses the following: • Soil and groundwater conditions • Geologic hazards areas per City of Everett Municipal Code(EMC) • Seismic design parameters per 2015 International Building Code(IBC) • Site preparation and grading • Excavations and slopes • Foundation support • Floor slab-on-grade support • Drainage • Utilities