4937 SEA BREEZE WAY 2017-01-13 - Laserfiche WebLink

! • Geotechnical Engineering Evaluation NGA File No. 916915 Pepe Retaining Wall April 27, 2015 Everett, Washington Page 10 geotechnical professiona] or soils technician. Field monitoring procedures would inciude 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 till should be suitably prepared as described in the Site Preparation and Grading subsection of this report prior to beginning fill placement. Materials: Structural fill should consist of a good quality, granular soil, free of organics and other deleterious material, and be well graded to a maximuin size of about three inches. All-weather structural till should contain no more than live-percent tines (soil finer than U.S. No. 200 sieve, based on that fraction passing the U.S. 3/4-inch sieve). The on-site soi] should not be used as structural till. We should be retained to eval��ate proposed structural fill �r�aterial prior to placement. Fill Placement: Following subgrade p�•eparation, 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 should be compacted to a minimuir� of 95 percent of its �naximum dry density. Maxiin�im dry density, in this report, refers to tha�t density as determined by the ASTM D-1557 Compaction Test procedure. �I�he moisture content of the soils to be compacted should be within about two percent of optimwn so that a readily coi��pactable condition exists. It inay be necessary to over- exeavate and remove wet soils in eases wherc drying to a coir�pactable conditioi� is not feasible. All compaction should be accomplished by equipinent of a type and size sufficient to attain the desired degree of compaction. Retaining Wall Repair or Replacement The extent of wall repairs or the decision to replace the wall should be determined by the structural engineer afteT• reviewing current wall conditions. At a minimum, the wall should be restrained from further lateral movement by installing an adequate nu�nber of tiebacks that are structurally tied to all of the steel beams. Also, the plastic lagging should be reir�oved and replaced with pressure-treated timber lagging. The existing beams should be evaluated for structural integrity and sufficient embedment. We should be retained to review final repair plans and provide specific recommendations for design and installation of retaining walls and fill placement. NELSON GEOTECHNICAL ASSOC/ATES, INC.