1130 RAINIER AVE WHOLE SITE DOCUMENTS 2016-01-01 MF Import

� Everett Housing Authority May 16, 2012 PAVEMENTAREAS � JN 12080 Page 11 The pavement seclion may be supported on competent, native soil, on structural fiil, or on existing fill compacted to a 95 percent density. Because the sile soils are silry and moisture sensitive, �ve recommend that the pavement subgrade must be in a slable, non-yielding condition at the time oi paving. Granular structural (ill or geotexlile fabric may be needed lo slabilize soft, wet, or unstable areas. To evaluate p2vement subgrade strenalh, we recommend ihat a proof roll be completed �;�ilh a loaded dump lruck immedialely before paving. In most instances oihere unslable subgrade condilions are encountered, an addilionat 12 inches of granular sfructural till viiil slabilize Ihe subc�rzde, except for very sefl areas :vhere adtlitional (ill could be required. i i?e subgrade shouid be ev2!uated by Geotech Consu!!arts, Ir:c., after lhe site is stripped and cut to grade. Rer,ommendalions for the cer:ipac(ion o` struclural fiil beneath pavements are given in the secticn enfitled General Earthwork and Structural Fill. The perionnance o( sile pavernents is direc(ly related to the strength and stability of Ihe underlyirg subgrade. The pavement for lightly ioaded traHic and pzrking areas should consist of 2 inches o( asphait concrete (AC) over 4 in�hes o( crushed rock base (CRF` or 3 inches of asphalt•ireated base (ATB). We recommend providing heavily loaded areas �vith 3 inches of AC over 6 inches o( CRB or 4 inches of ATB. Heavily loaded areas are typically main driveways, dumpster sites, or areas with truck lraffic. Increased maintenance and more frequent repairs should be expected if thinner pavement sections are used. Water from planter areas and other sources should nol be allotived to infiltrate into the pavement subgrade. The pavement section recommendations and guidelines presented in this report are based on our experience in the area and on what has been success(ul in similar siluations. As wlth any pavements, some maintenance and repair oF limited areas can be expecled as the pavement ages. Cracks in the pavement should be sealed as soon as possible after they become evident, in order to reduce the potential for degradalion of the subgrade from infiltralion of surface water. For the same reason, it is also prudent to seal the surface of the pavement a(ter it has been in use for several years. To provide for a design without ihe need for any maintenance or repair would be uneconomical. GENERAL EARTHWORK AND STRUCTURAL FILL All building and pavement areas should be stripped of surface vegetation, topsoil, organic soil, and olher deleterious material. The stripped or removed materials should not be mixed wilh any materials to be used as struclural till, but Ihey could be used in non-structural areas, such as landscape beds. Structural fill is defined as any fill, including utility back(ill, placed under, or close to, a building, behind permanent retaining or foundation �valls, or in other areas where the underlying soil needs to support loads. All slructural fill should be placed in horizonlal litts �vith a moisture content at, or near, the optimum moisWre conlent. The optimum moislure content is lhat moisture content lhat results in the grealest compacted dry density. The moisture content of fill is very important and must be closely controlled during the filling and compaction process. Thc allowable thickness of the tili lift will depend on the materlal type selected, the compaclion ec;uipment used, and the number of passes made to compact the Iiit. The loose litt thickness =nould not exceed 12 inches. We recommend tesling the fill as il is placed. If the fill is not su(ficien�ly compacted, it can be recompacted before another lift is piaced This eliminates lhe CEO��CH CO�dSULTAWTS, iNC.