1329 MADRONA AVE Geotech Report 2022-10-25

Subsurface Exploration,Geologic Hazard,and Janowicz Property Geotechnical Engineering Report Everett,Washington Preliminary Design Recommendations washed pea gravel to act as a capillary break. They should also be protected from dampness by a vapor retarder. 14.0 DRAINAGE CONSIDERATIONS All basement and retaining walls should be provided with a drain at the footing elevation. Drains should consist of rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by washed pea gravel. The level of the perforations in the pipe should be set at or slightly below the bottom of footings, and the drain collectors should be constructed with sufficient gradient to allow gravity discharge away from the building. In addition, backfilled foundation walls should be lined with a minimum, 12-inch-thick, washed gravel blanket provided to within 1 foot of finish grade that ties into the footing drain. Roof and surface runoff should not discharge into the footing drain system,but should be handled by a separate,rigid,tightllne drain. Surface runoff from the driveway should be collected and directed away from the slope and toward an approved facility. In planning,exterior grades adjacent to foundations should be sloped downward away from the structure to achieve surface drainage. 15.0 DRIVEWAY The driveway should be constructed atop medium dense or dense natural sediments, or atop structural fill soils. The structural fill should be constructed as previously recommended. The edge of the structural fill should extend a minimum of 3 feet beyond the edge of the paved area or sidewalks before sloping to grade. We recommend a paving section that includes a minimum of 2 inches of Class B asphalt concrete pavement (ACP) atop 3 inches of asphalt treated base (ATB) atop 4 inches of crushed surfacing base course. The crushed rock shall be compacted to a firm, non-yielding condition, and the asphalt layers should be compacted per Washington State Department of Transportation (WSDOT) standards. We recommend that all subgrades be proof-rolled under the observation of an AESI field technician or geotechnical engineer prior to placing pavement materials to identify any soft or yielding areas. Proof-rolling consists of tracking a loaded, 10-yard dump truck across the subgrade and watching the performance of the subgrade under the loading of the rear tires. Identified, unsuitable areas should be removed and replaced with structural fill or an approved rock course. 16.0 PROJECT DESIGN AND CONSTRUCTION MONITORING We are available to provide additional geotechnical exploration and consultation as the project design develops and possibly changes from that upon which this report is based. We recommend that AESI perform a geotechnical review of the plans prior to final design May 10,2018 ASSOCIATED EARTH SCIENCEs,INC. NS/1d-17o6a5E0o2-2-Projectsj201706491KE{WP Page 19