2721 WETMORE AVE MARQUEE APARTMENTS Geotech Report 2023-06-22

Subsurface Exploration, Geologic Hazard, and 2721 Wetmore Preliminary Geotechnical Engineering Report Everett, Washington Preliminary Design Recommendations For this project, it can be assumed that the vertical and horizontal dynamic subgrade modulus for the very stiff to hard/dense to very dense native soil is 150 and 100 pci, respectively. 13.5 Monitoring Program A program should be established to monitor the horizontal and vertical movement of the excavation sidewalls and the installed shoring wall. This monitoring program will be required by the City of Everett. The monitoring should be performed by a licensed surveyor with monitoring points established on settlement-sensitive structures (buildings, manholes, poles, etc.) around the excavation and at regular intervals along the shoring wall. Monitoring should be performed at least twice a week and the specifics of the monitoring program should be provided to AESI for review prior to implementation. We recommend the monitoring program be prepared as part of the final shoring wall design. 14.0 BASEMENT WALL DESIGN PARAMETERS Permanent basement wall design can be performed based on apparent earth pressures presented for the temporary shoring design with the addition of a seismic surcharge loading. Additional lateral loads associated with seismic activity should be incorporated into permanent wall design. Based upon review of the site location the additional loading due to seismic event should be 8H to 11H, for an active or at-rest condition, respectively. 15.0 PROJECT DESIGN AND CONSTRUCTION MONITORING The recommendations contained in this report are preliminary. The conclusions and recommendations of this report should be reviewed and modified, as necessary, to reflect the additional exploration borings and a more mature building design. We are available to provide additional geotechnical consultation as the project design develops and possibly changes from that upon which this report is based. We recommend that AESI perform a geotechnical plan review of all earthwork, foundation, or shoring-related specifications prior to completion of the final design. In this way, our earthwork and foundation recommendations may be properly interpreted and implemented in the design. We are also available to provide geotechnical engineering and monitoring services during construction. The integrity of the foundation depends on proper site preparation and construction procedures. In addition, engineering decisions may have to be made in the field in the event that variations in subsurface conditions become apparent. Construction monitoring services are not part of this current scope of work. May 28,2019 ASSOCIATED EARTH SCIENCES,INC. FSM/Id-190168E001-2-Projects\20190168\KE\WP Page 20