9910 EVERGREEN WAY SPRINT ANTENNA 2018-01-01 MF Import

� ' LSI Adapr Clearing and Grubbine: We do not anticipate that sisnificant grade changes will be required to achieve proposed site grades. At this location, site preparation will consist of the removal of the asphalt, near- surface soil and limited grading, followed by foundation preparation 1'or the monopole tower and eqeipment cabinct foundation. Backfill materials, where required, should be placed and compacted according ro the recommendations presented in the Structural Fill section of this repori Wet Conditions: Because o1'the fines content of the near surface soils, the existing site soils at shallow depths are extremely r.ioisture-sensitive, and will be prone to disturbance when wet. The contractor should minimize traiiic aoove thr, prepared subgrade areas to minimize disturbance and softening which would requi• : removal of the unstable soils. During wet conditions, the us� of a working surface of quarry spalls or clean sand and gravel may be required to protect the subgrade, especiaily from vzhicular traffic. Frozen Subgrades: If earthwork takes place during freezing conditions, we recommend that all exposed subgrades be allowed to thaw and be racompacted prior to placing subsequent lifts of structural fill. Frozen materials, ice and sno�v should be prohibited from Structural Fill. Equipment Cahinel Foundntion It is our undcrstanding that the foundation for the proposed concretc equipment pad will consist of a concrete slab-on-grade. We anticipate that the net bearing pressure will be relatively light, as the weight of the pad and equipment will likely be less than the weight of the excavated soils displaced by the pad. However, we recommend that the slab edges be evaluated as spread 1'ootings. The following recommendations and comments are provided for purpnses of footing design ar.d conswction: Suberade Conditions: The proposed equipment pad may be supported by thickened slab edges extended to bear on the existing site soils encountered at depths below I.5 feet at the location of boring B-1, after they have been campac[ed in place resulting in a firm and unyielding subgrade condi[ion, or upon structural fill placed above similarly prepared soils. We anticipate the subsoil encountered at the proposed foundation grade will likely consist orloose, silty sand with organics. Depending on the time of year that cunstruction proceeds, it may be difficult o. impossible to compact those soils in place. It will be difficult ro achieve a specified compaction should moisture contenu sienificantly above the optimal moiswre condition be encountered. Some overexcavation may be necessary if excessively sofl or wet subgrade conditions were to be encountered at the 1'oundation design grade levels. In consideration of the light loads imposed by the equipment, we recommend the overexcavation extend no deeper than 2-feet below the thickened slab bearing elevation. A layer of geotextile may be required to separate the structural fill soils from the underlying subgrade materials. Footings should never be casl atop sofi, loose, organic, or frozen soils; nor atop subgrades covered by standing water. A representative from Adapt should be retained to observe the condition of footing subgrades before concrete is poured to verify that they have been adequately prepared. Spnm PCS August 4, 2003 !/ Adap� Project No. \VAU3-9720 a�F� q ( 7