3611 FEDERAL AVE 2018-01-02 MF Import

Geologic /m,evtigation and Geotechnical Engineering Repor! 98-08-10 Jones Reddence 3611 Federal. -he. Everett, Washington 4.7 Gravity Retaining Walls At the time of preparation of this report, we are aware of the possibility of at least one retaining wall on the project site. This wall would be located at the bottom of the driveway/access road into the site and would retain structural fill placed for the driveway. The retaining wall would be located below grade. For ease of construction and cost considerations, we would recommend utilizing a Lock Block Retaining Wall System from Ultra Block of Vancouver, Wa. for this application. A Lock Block Wall Detail and construction specifications are given in Appendix F of this report. 4.8 Seismic Considerations The Puget Sound Lowland Physiographic Province is a seismically active area. Earthquakes ranging between 1.0 to 3.5 on the Richter scale are recorded on a regular basis. Larger earthquakes are not quite as prevalent, however, several have been recorded in the Province within the last few years. Careful and prudent engineering practices are necessary to limit damages incurred during seismic events. In general. wood framed structures such as the one proposed for this site tend to be fairly forgiving and have a high survivability rate during seismic events. Due to the massive. dense to very dense nature of the Transitional Beds (Qtb) Silts below this site and the lack of any observable indications of shallow ground water at the time of our investigation, it appears that the site soil will not be subject to liquefaction potentials and should remain relatively stable during most anticipated seismic events. 4.9 Drainage Controls Overall long-term soil stability, foundation settlement potentials and long term foundation stability will be influenced by drainage controls in and around the exterior of the building. We recommend that all exterior footings be drained by a minimum 4" diameter perforated PVC drain line laid alongside the base of the footing so as to positively drain toward an appropriated point of discharge. The footing drain should be 14 GES, Inc.