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[� 5FA Design Group, LLC <br />STRUCTURAL I GEOTECHNICAL I SPECIAL INSPECTIONS <br />Concrete Backfill(s) Alona Gridline <br />PROJECT NO. ISHEET NO. <br />Concrete Backfill Dimensi- -" -- - — _ ^ --- - ons <br />Effective Friction Angle = 26 <br />Passive Coefficient, Kp = tan A2*(45+0'/2) <br />Kp = 2.57 <br />Passive Pressure, Pp = 2.57 * 100 = 257 pcf <br />Cohesion, c' = 1500 psf <br />Soil Unit Weight, y = <br />100 pcf <br />Depth of Backfill, d = <br />2.0 It <br />Width of Backfill, w = <br />1.5 ft <br />Depth to Backfill, r = <br />2.0 It <br />Soil Neglected = <br />1.0 ft <br />Backfill Depth Below Grade = <br />4.0 It <br />Passive Lateral Resistance Acting on Concrete Backfll <br />Passive Pressure at Base, up '= Pp (d+r) <br />256.8pcf * (4 ft) = ap' = 1027 psf <br />Lateral Capacity/Pier, Rp = ((A+B)/2)*d <br />Rp=((A+B)/2)*d=((770 p1f+1541 plo/2)*2 ft = 2311 lbs <br />IftNEGLECTED <br />Depth to Backfill - 1 ft = 1 ft <br />Depth of Backfill d = 2 ft <br />LOADING DIAGRAM PER PIER <br />= (Kp*y*r)*w = 770 plf <br />Rp = 2311 Ibs <br />I = (Kp*y*(r+d))*w = 1541 plf <br />Isf <br />Literal Resistance per Pier <br />Concrete Backfill Spacing = <br />30.6 It (20.39B) <br />P-Multiplier 1st Backfill = <br />1.00 <br />P-Multiplier 2nd Backfill = <br />perAASHTO TABLE BELOW <br />1.00 <br />P-Multiplier Other Backfills = <br />(INTERPOLATION OK) <br />N/A <br />Number of Piers to Be Backfilled = <br />2 pier(s) <br />Lateral Resistance of 1st Backfill = <br />1 * 2311 Ibs = 2311 Ibs <br />Lateral Resistance of 2nd Backfill = <br />1 * 2311 Ibs = 2311 Ibs <br />Lateral Resistance of Other Backfills = <br />N/A <br />Table 10.7.24.1—Pile P-Multlpllers, a, for hiulllple Row Shading (averaged from Hannigan et aL, 2006) <br />Pile CTCspachig of the direction of <br />loadh ) <br />P-Muldphers, P,o <br />Row 1 <br />Row 2 <br />Row 3 and ]d her <br />3B <br />0.8 <br />0.9 <br />1.3 <br />5B <br />1.0 <br />0.85 <br />0,7 <br />Total Lateral Resistance of Piering System - -. _ - - - - <br />—__"------- ----- __- --- -- ----- ----1 <br />Lateral Resistance = 1 st Backfill + 2nd Backfill + Other Backfills + Slab + Unplered + Passive Pressure on Footing + Pier Passive + Tiebacks <br />Total Lateral Resistance = 2311 Ibs + 2311 Ibs + 0 Ibs + 0 Ibs + 0 Ibs + 198 Ibs + 0 Ibs + 0 Ibs = 4820 Ibs <br />Factor of Safety = <br />1.1 <br />Allowable Resistance = <br />4382 Ibs >3761 Ibs OK <br />(Polyurethane Foam Capacity <br />Compressive Strength of Foam = <br />67.0 psi <br />Diameter of Pier = <br />2.875 in 0 <br />Area of Pier Bearing on Foam = <br />69.00 in' <br />Bearing Strength of Pier on Foam = <br />4623 lb <br />Factor of Safety = <br />2.0 <br />Bearing Strength of Pier on Foam = <br />2312 lb OK, Soil Bearing Controls <br />