9908 18TH AVE W 2024-12-03 - Laserfiche WebLink

Pacific Ridge — DRH, LLC ES-7852.01 March 15, 2022 Page 6 Existing Fill Removal and Replacement Existing fill extending to depths of up to about four to six feet bgs should be anticipated in the western/southwestern portion of the site. The existing fill is not suitable for structural support in its current condition. The following is recommended for existing fill removal and replacement in structural areas: • Overexcavate existing fill and segregate deleterious material from suitable fill soil (if practicable). • Place a layer of quarry spalls which extends above moderate to heavy groundwater seepage. • Cover quarry spalls with filter fabric. • Begin mass grading with structural fill. The suitability of the existing fill for reuse and the need for quarry spalls (and thickness) can be further evaluated by ESNW during construction. In-situ and Imported Soils The in-situ soils encountered at the subject site have a high sensitivity to moisture and were generally in a moist to wet condition at the time of exploration. Soils anticipated to be exposed on site will degrade if exposed to wet weather and construction traffic. Compaction of the soils to the levels necessary for use as structural fill may be difficult or impossible during wet weather conditions. Soils encountered during site excavations that are excessively over the optimum moisture content will likely require aeration or treatment prior to placement and compaction. Conversely, soils that are substantially below the optimum moisture content will require moisture conditioning through the addition of water prior to use as structural fill. Areas of existing fill may be unsuitable for reuse as structural fill due to composition and/or deleterious material. An ESNW representative should determine the suitability of in-situ soils for use as structural fill at the time of construction. Imported soil intended for use as structural fill should be evaluated by ESNW during construction. The imported soil must be workable to the optimum moisture content, as determined by the Modified Proctor Method (ASTM D1557), at the time of placement and compaction. During wet weather conditions, imported soil intended for use as structural fill should consist of a well-graded, granular soil with a fines content of 5 percent or less (where the fines content is defined as the percent passing the Number 200 sieve, based on the minus three-quarter-inch fraction). Earth Solutions NW, LLC