3003 W CASINO RD 1992 SITE DEV 2018-01-01 MF Import

�DRAFT structure. KeysWne Retaining Walls have been installad around other nearby pazking lou at the Boeing Everett Facility. Detailed design parameters can be provided if this type of wall is selected. OeotexUle or Reiniorced Eerth Wail Geoteztile walls are conttruaed by placing the geotezale in layers wittiin the fiil with about 1 foot of compacted soil between the layers. 'It�ese walls are also relatively low cost although they typically do not provide a uniform face. A "Reinforced Eanh Retaining Wall" is wnswcced by using metallic reinforcemeot svips layered within the fill. In most cases, the reinforced carth mazs has a facing of precast concrete. T'6is type of retaining wall is the most expensive and is more suitable for larger embankments. PAVEMENT CONSIDERATIONS The pavement subgrade should be prepared in accordance with our recommendations for site preparation. We recommend that the parking area subgrade be thoroughly proofrolled with heavy equipment in areas of cut or areat disturbed by construccion to ezpose areas of aoft, loose or wet soils which require additional compaaion or excavation and replacement with structural fill. Recommendations for placement and compaction of subgrade soils are p:esented in a previous section of this report. Because of the rapid construction schedule, trafficability of the siiry-sand soils and for drainage considerations, we recommend that a subbaze layer be planned az part of the pavement� sectioa in parking and driveway areas, The subbaze layer should consist of a minimum 8-inch thicirness of I'h-inch minus material with less than 5 percent passing the U.S. No. 200 sieve. We recommend a CBR value of 15 be used for design of pavement sections over subgrade placed and compacted as recommended. ' DRAINAGE CONSIDERATIONS We recommend that the parking areas be sloped lo drain such that sur(ace runoff is collected and carried off the site. 1he subbase recommended for support of the pavement will aa as a drainage layer to transport the water from beneat� the pavement section. LIMITATIONS We 6ave prepared ehis report for use by Reid Middleton, The Boeing Company and other members of the design tcam for use in design of a portion of this project, The report is not inteaded for use by others and the information contained herein is not applicable to other sites. The data and report should be provided to prospecti�e contractors for their bidding or estimating purposes, but our report, conclusions and interpretations should not be conswed az a warranty of the subsur[ace conditions. G c o E n p i n e s t � IO Filc No.01I0.150.R10�062292