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

i �� � Adapt Engineering End Bearin� Capacities: We recommend that the drilled pier penetrate at least 10-feet below the ground surface. For vertical compressive soil bearing capacity, we recommend using the unit end bearing capacity presented in Table 1 below, where B is the diameter of the pier in feet and D is the depth into the bearing layer in feet, in accordance with the EIA/TIA G-code. This ultimate end bearing capacity does not include a safety factor. Table 1 Ultimate Gnd Bearing Capacity Depth (feet) Ultimate F3earing Capacity (ts� Limiting Point Resistance (ts� 10-35.5 7.0 D/B 10 Frictional Capacities: For frictional resistance along the shaft of the drilled piers, acting both downward and in uplift, we recommend using the ultimate skin friction value listed in Table 2. We recommend that frictional resistance be neglected in the uppermost 2-feet below the ground surface. The ultimate skin friction values presented do not include a safety factor, in accordance with the provisions of the EIA/TIA 222-G code. Table 2 Ultimate Skin Friction Capacities Depth (feet) Ultimate Skin Friction (ts� 0-2 0.0 2-5 0.5 5-35.5 1.0 Lateral Capacities: Drilled pier foundations for communication monopole towers are typically rigid and act as a pole, which rotates around a fixed point at depth. Although more complex and detailed analyses are available, either the simplified passive earth pressure method or the subgrade reaction method is typically used to determine the pier diameter and depth required to resist groundline reaction forces and moments. These methods are described below. • Passive Earth Pressure Method: The passive earth pressure method is a simplified approach that is generally used to estimate an allowable lateral load capacity based on soil wedge failure theory. Although the lateral deflection associated with the soil wedge failure may be estimated, design lateral deflections using the passive earth pressure method should be considered approximate, due to the simplified nature of the method. According to the NAVFAC Design Manual 7.02 (1986), a lateral deflection equal to about 0.001 times the pier length would be required to mobilize the allowable passive pressure presented below; higher deflections would mobilize higher passive pressures. The ultimate passive pressure may be taken as the product of the allowable pressure and factor of safety. Our recommended passive earth pressures for the soil layers AT&T Mobility Go Ryka Consulting May 5, 2014 Adapt Project No. WA14-18929-GEO Page 8