505 LAUREL DR 2025-03-12 - Laserfiche WebLink

Miles Residence Pool Everett, Washington Limited Geologic Hazard Reconnaissance Perimeter footings should be buried at least 18 inches into the surrounding soil for frost protection. However, all foundations must penetrate to the prescribed bearing strata, and no foundations should be constructed in or above loose, organic, or existing fill soils. Anticipated settlement of footings founded as recommended should be on the order of 1 inch or less, with differential settlement of %2 inch or less. However, disturbed material not removed from footing trenches prior to footing placement could result in increased settlements. All footing areas should be observed by AESI prior to placing concrete to verify that the foundation subgrades are undisturbed and construction conforms to the recommendations contained in this letter -report. Such observations may be required by the City of Everett. Perimeter footing drains should be provided. It should be noted that the area bounded by lines extending downward at 1H:1V (Horizontal:Vertical) from any footing must not intersect another footing or intersect a filled area that has not been compacted to at least 95 percent of ASTM International (ASTM) D-1557. In addition, a 1.5H:1V line extending down and away from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings should not be placed near the edges of steps or cuts in the bearing soils. Lateral Wall Pressures Horizontally backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be designed using an equivalent fluid equal to 35 pounds per cubic foot (pcf). Fully restrained, horizontally backfilled, rigid walls that cannot yield should be designed for an equivalent fluid of 55 pcf. Walls that retain sloping backfill at a maximum angle of 2H:1V should be designed for 55 pcf for yielding conditions and 75 pcf for restrained conditions. If parking areas are adjacent to walls, a surcharge equivalent to 2 feet of soil (i.e., 250 psf) should be added to the wall height in determining lateral design forces. Undrained walls/structures must be designed for combined soil and hydrostatic pressures (85 pcf for yielding walls, 100 pcf for unyielding walls with horizontal backfill) and for buoyant/uplift forces. In accordance with the International Building Code (IBC), retaining wall design should include seismic design parameters. Based on the mapped site soils and assumed wall backfill materials, we recommend a seismic surcharge pressure in addition to the equivalent fluid pressures presented above. A rectangular pressure distribution of 5H and 10H psf (where H is the height of the wall in feet) should be included in design for "active" and "at -rest" loading conditions, respectively. The resultant of the rectangular seismic surcharge should be applied at the midpoint of the walls. Wnll Rnrkfill The lateral pressures presented above are based on the conditions of a uniform backfill consisting of either the on -site glacial sediments, or imported sand and gravel compacted to 92 percent of ASTM D-1557. A higher degree of compaction is not recommended, as this will increase the pressure acting on the walls. A lower compaction may result in unacceptable settlement behind November 15, 2022 ASSOCIATED EARTH SCIENCES, INC. JPL/jh - 20220343EO01-003 Page 3