b'4. Determine Ultimate Torque Anchor Load: 7. InstallationTorque. Use Graph1fromUse Equation 3 from Chapter 1 to determine the Chapter 4, shown on next page to determine theultimate capacity per pile: installation torque requirement for the piles.TheP u= (X) x (w) x (FS): Ultimate Capacity from Step 4 is 21,263 pounds.Where, Find 22,000 pounds at the left side of Graph 2X = Product Spacing = 6-3/4 feet lookhorizontallytothegraphlineforsolidw = 1,575 lb/lineal foot (Step 1) square shafts, read down to torque of 2,200 ft-lb. FS = Factor of Safety (Use 2.0) T = 2,200 ft-lbP u= 6-3/4 ft x 1,575 lb/ft x 2 = 21,263 lb5.Selecttheproperpileconfiguration: By comparison, the installation torque isReferringtoGraph4 -Chapter1(reproduced calculated: from Equation 2 in Chapter 1:below), notice that the capacity line for 12 and Equation 2:T = P u/ k,14diameterhelicalplatesattachedtoshaftP u= 21,263 lb k = 10 (Table 12)crosses just above 20,000 pounds at the center of T = 21,263 lb/10 ft -1= 2,127 ft-lbSoilClass6. The12and14diameterplate 8.InstalledProductLength.Terminationconfiguration is selected for the design. depth is the stiff clay.It is likely that the pile6.CheckShaftStrengthsandTorsional would reach the desired shaft torsion at a depthStrengths to see which shaft is suitable: Refer somewherebeyondtheunconsolidatedsoiltoTable2inChapter1to verifythe shaft neargrade. Theminimumdepthistheselection has a suitable Axial Compression Load summation of the Critical Depth, defined as 6Limit and sufficient Useable Torsional Strength. x diameter of largest plate plus the distance toThe1-1/2inchsolidsquareshaftis verified the lowest plate.because it has an Axial Compression Load Limit Minimum Required Shaft Length:ratingof70,000poundsbaseduponan L min= D Critical + L Tip Where:installation torsional limit of 7,500 ft-lbs.This D Ccritical= 6 x (14 dia./12)pile exceeds the ultimate job load requirement of L Tip= 14 dia./12 x 3 = 3.5 ft21,263pounds.Theselectedandverifiedpile (Plates spaced at 3 x diameter.)configuration is TAF-150-60 12-14. L min = 6 x (14/12)+(14/12 x 3) = 10-1/2 ftTORQUE ANCHOR HOLDING CAPACITYMultiple Helical Plate Sizes12-14" 8-10-12" 10-12-14" 12-14-14"120000Estimated Ultimate Capacity10000080000600004000020000 Earth Contact Products0Graph 4. 1 7 263 5 4 453 6Soil ClassificationECP Technical Design ManualTorque Anchor Design Examples2021 Earth Contact Products, L.L.C.2021-09 Chapter 5Page 101 All rights reserved'