7710 EVERGREEN WAY NEW CINGULAR WIRELESS ANTENNA 2016-09-26

CJ • Adapt Engineering ultimately depend on the actual soil, rock and groundwater seepage conditions exposed in the cuts at the time of construction. It is the responsibility of the contractor to ensure that the excavation is properly sloped or braced for worker safety protection, in accordance with OSHA safety guidelines. In any case, appropriate inclinations will ultimately depend on the actual soil, rock and groundwater seepage conditions exposed in the cuts at the time of construction. It is the responsibility of the contractor to ensure that the excavation is properly sloped or braced for worker protection, in accordance with OSHA guidelines. In addition to proper sloping, the excavation cuts should be draped with plastic sheeting for the duration ofthe excavation to minimize surface erosion and ravelling. Dewaterin�: Based on our site reconnaissance investigation, we do not anticipate significant groundwater seepage within the upper 4-feet. However, perched groundwater may be encountered depending on the actual excavation depth and the time of year that construction proceeds. If groundwater is encountered, we anticipate that an internal system of ditches, sump holes, and pumps will be adequate to temporarily dewater the excavations. Subgrade Preparation: Exposed subgrades for shallow footings, mat foundations, slabs-on-grade, roadway sections and other structures should be compacted to a firm, unyielding state, if required to achieve adequate density and warranted by soil moisture conditions. Any localized zones of loose, granular soils observed within a subgrade area should be compacted to a density commensurate with the surrounding soils. In contrast, any uncontrolled fill material or organic, soft, or pumping soils observed within a subgrade should be overexcavated and replaced with a suitable structural fill material. It should be noted that the near-surface bearing soils at this site are anticipated to consist of silty sandy clays, which are generally considered to be moderately to extremely moisture sensitive. To minimize disturbance and subsequent need for recompaction, we therefore recommend that all bearing subgrade areas be excavated with a smooth-edged bucket. Frozen Sub =rades: If earthwork takes place during freezing conditions, we recommend that all exposed subgrades be allowed to thaw and be recompacted prior to placing foundations or subsequent lifts of structural fill. Equipment Foundations It is our understanding that support for the proposed equipment cabinet pad will consist of a poured-in- place, concrete slab-on-grade with thickened edges; we recommend that these thickened slab edges be designed as spread footings. Alternatively, the equipment support pad may be designed as a structural slab-on-grade with a uniform thickness and a reduced bearing pressure. In either case, we anticipate that the support pad bearing pressure will be relatively light. The following sections provide our recommendations and comments for equipment pad design and construction. Subgrade Conditions: The prepared bearing subgrade soils should consist of firm and unyielding, very dense sand with gravel, crushed rock, and rock spalls. Exposed slab-on-grade, footing or overexcavation subgrades should be compacted to a firm, unyielding state, in accordance with the recommendations provided in the Site Preparation section of this report. AT&T Mobility c/o Ryka Consulting May 5, 2014 Adapt Project No. WA14-18929-GEO Page 5