3500 TERMINAL AVE Geotech Report 2022-10-25

Port of Everett—South Terminal Wharf& Electrical Upgrades—Phase 2 129 ■ The backfill should be continuous and envelop the drainage behind the wall. Site Drainage Final grades should be sloped to carry surface water runoff away from structures to prevent water from infiltrating near the foundation walls. Roof drainage and new surface water drainage should not be tied into the subdrain system and should not discharge onto the site. Pavement Recommendations We understand that the upland pavement will be based on the Port of Everett's Standard Pavement Section,consisting of 12 inches of asphalt concrete over 12 inches of crushed rock base.The wharf paving will consist of 6 inches of asphalt concrete over 12 inches of crushed rock base,over the existing concrete panels.We understand that new pavement will be placed only in areas where utility trenches have been excavated and the existing building demolished.The above pavement sections are considered suitable, provided that at least the upper 2 feet of subgrade is inspected by a Hart Crowser representative and compacted to 95%relative density.The existing base course may be suitable for reuse as base course, provided that it is inspected and approved for reuse by a Hart Crowser representative. Earthwork Recommendations Site Preparation and Grading We recommend all site grading, paving,and any utility trenching be conducted during relatively dry weather conditions. It may be necessary to relocate or abandon some utilities. Excavation of these utility lines will probably occur through fill.Abandoned underground utilities should be removed or completely grouted. Ends of remaining abandoned utility lines should be sealed to prevent piping of soil or water into the pipe.Soft or loose backfill should be removed,and excavations should be backfilled with structural fill. Coordination with the utility agency is generally required. Structural Fill Backfill placed within the building area or below paved areas should be considered structural fill.We make the following recommendations for structural fill: • For imported soil to be used as structural fill, use a clean,well-graded sand or sand and gravel with less than 5 percent by weight passing the No. 200 mesh sieve (based on the minus 3/4-inch fraction). Compaction of soil containing more than about 5 percent fines may be difficult if the material is wet or becomes wet during rainy weather. • Place and compact all structural fill in lifts with a loose thickness no greater than 10 inches. For hand- operated"jumping jack"compactors, loose lifts should not exceed 6 inches. For small vibrating plate/sled compactors, loose lifts should not exceed 3 inches. Ns I.I 19232-01 HARTO? V5 R December 6,2017