330 ELM ST VIEW RIDGE ESTATES 2022-04-04

• Geotechnical Engineering Evaluation NGA File No. 1085419 View Ridge Estates 330 Building Settlement March 22,2019 Everett,Washington Page 9 replaced with 2-inch crushed rock for support of the new slab. The crushed rock should be placed in a maximum 8-inch thick lifts and each lift compacted to a firm unyielding condition. The new slab could be supported on the resulting firm subgrade. The slab should be additionally reinforced and doweled cold joints should be incorporated into the slab design to further reduce the effects of differential settlement. Some slab settlement, differential settlement, and cracking should still be expected, if the slab is not supported on pin piles/helical anchors. Structural Fill General: We do not anticipate significant structural fill placement for this project; however, fill placed beneath foundations,pavement, or other settlement-sensitive structures should be placed as structural fill. Structural fill, by definition, is placed in accordance with prescribed methods and standards, and is monitored by an experienced geotechnical professional or soils technician. Field monitoring procedures would include the performance of a representative number of in-place density tests to document the attainment of the desired degree of relative compaction. The area to receive the fill should be suitably prepared to a firm,non-yielding condition prior to fill placement as described below. Materials: Structural fill should consist of a good quality, granular soil, free of organics and other deleterious material, and be well graded to a maximum size of about three inches. All-weather structural fill should contain no more than five-percent fines (soil finer than U.S. No. 200 sieve, based on that fraction passing the U.S. 3/4-inch sieve). The use of on-site soils as structural fill is not recommended. We should be retained to evaluate proposed structural fill material prior to placement. Fill Placement: Following excavation to final subgrade,placement of structural fill may proceed. All fill placements should be accomplished in uniform lifts up to eight inches thick. Each lift should be spread evenly and be thoroughly compacted prior to placement of subsequent lifts. All structural fill underlying building areas and pavement subgrade should be compacted to a minimum of 95 percent of its maximum dry density. Maximum dry density, in this report, refers to that density as determined by the ASTM D-1557 Compaction Test procedure. The moisture content of the soils to be compacted should be within about two percent of optimum so that a readily compactable condition exists. It may be necessary to over-excavate and remove wet soils in cases where drying to a compactable condition is not feasible. All compaction should be accomplished by equipment of a type and size sufficient to attain the desired degree of compaction and should be tested. I2 � 2� NELSON GEOTECHNICAL ASSOCIATES, INC.