6301 36TH AVE W 2016-11-01 - Laserfiche WebLink

' Geotechnical Report Powdermill Business Center 36th Avenue West ' Everett, Washington 1.0 PROJECT DESCRIPTION Tlie project consists of developing the approximately 35-acre site with industrial buildings and associated site infrastructure. Based on the site and grading plans prepared by PacLand, Phase I buildings are located on the ' west side of the site. The buildings are proposed to be terraced with building grades descending from west to east. Finished floor grade of the western most building is Elevation 443 and with the adjacent east building at Elevation 420. Grading to establish building and roadway elevations will involve cuts approaching 37 feet in the west-southwestern site areas with fills of 10 to 28 feet in the north and eastern site areas. The development will be accessed from the west off of 36th Avenue West. Grade transitions throughout the site will be supported with site retaining walls, rockeries, or 2:1 (HorizontaiXertical) slopes. ' We understand the buildings will be constructed using precast concrete tilt-up wall panels with interior columns supporting the roof framing. Structural loading is expected to be light to moderate, with isolated columns carrying loads of 50 to 200 kips, and bearing walls carrying 4 to 8 kips per foot. The building floors will be ' constructed at grade with dock high loading on the east sides of the buildings. Stormwater will be collected and routed to a detention pond located in the northeastern portion of the site. The ' pond will be formed by a combination of excavation below current site grade and construction of a fill contaimnent berm along the north, east, and west perimeters. The excavation required to achieve the floor elevation of 391 will extend 10 to 19 feet below current site grades. The fill depth required to achieve the berm ' crest elevation of 407 will range from 1 to 7 feet. The pond berm width is 15 feet, with exterior and interior pond slopes graded at 2:1 and 3:1, respectively. The recommendations contained in the following sections of this report are based on our understanding of the above 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 ' On July 24 and 25, 2008, we explored subsurface conditions at the site by observing the excavation of 14 test pits to depths of about 10 to 15 feet below existing surface grades using a track-mounted excavator. We revisited the site on July 29, 2008 to observe the drilling of 2 soil test borings to a maximum depth of 30.5 feet below existing site grades. Using the information obtained from our subsurface explorations and laboratory testing, we performed analyses to develop geotechnical recommendations for project design and construction. Specifically, this report addresses the following: ' • Soil and groundwater conditions • Geologic hazards ' • Site preparation and grading • Excavations o Slopes and embankments