1004 BROADWAY EVCC STUDENT HOUSING - PUBLIC WORKS 2017-01-13

Geotechnical Report - Revised Proposed Apartments: 1002, 1006, and 1008 Broadway Street, Everett, Washington Mav 1 Z, 20l 5 6.2 STRUCTURAL FILL AND COMPACTION Structural iill, should be fi�ee af organic and inorganic debris, Ue near the optimum moisture content and be capable of being compacted to the recommendations pi•ovided bclow. If the site soils cannot be compacted, then an imported structural fill may be needed. Fill for use during wet weather should consist of a well graded soil free of organic material with less than 5 percent fines (silt and clay sized particles passing the U.S. 200 sieve). St�uctural fill should be moisture conditioned to within about 3 pei•cent of optimum moisture content, placed in loose, horizontal lifts less than 8 inches in thickness, and compacted to at least 95 percent maximum density, determined using ASTM D-1557 (Modified Proctor). The procedure to achieve proper density of a compacted fill depends on the size and type of compacting equipment, the nuinber of passes, thickness of the lifts being compacted, and certain soil properties. If the excavation to be backfilled is constricted and limits the use of heavy equipment, smaller equipment can be used, but the lift thickness will need to be reduced to achieve the required relative compaction. Generally, loosely compacted soils are a result of poor construction teclulique or impropes moisture content. Soils with high iines contents �re particularly susceptible to becoming too wet and coarse-grained materials easily become too dry, for proper compaction. Silty or clayey soils with a moisture content too high for adequate compaction should be dried as necessary, or moistui•e conditioned by mixing with drier materials, o�• other methods. G.3 WET WEATHER CONSTRUCTION General recommendations relative to earthwork perfonned in wet weather or in wet conditions are presented below. The following procedures are best managemenc practices recommended for use in wet weather consttuction: • Earthwork should be pet•formed in srnall areas to minimize subgrade exposure to wet weather, Excavation or tlie removal of unsuitable soil should be followed promptly by the placement and compaction of clean st�uctural fill. The size and type of construction equipment used may have to be limaied to prevent soil disturbance. I 5-043 1008 E3roadway, Revised Page 14 PanGEO, Inc.