b'5. Installation Torque:A.) Use Graph1from GRAPH 6 -MOTOR OUTPUT TORQUE vs ULTIMATE CAPACITYGraph 1.Chapter 4 or B.) Equation Torque Efficiency Factor - "k" to Shaft Configuration2 fromChapter1to 240determine the installation 220Sq. Shaft (k = 10)torquerequirementfor 2002" Sq. Bar (k = 8.5)Ultimate Capacity x 1,000 lb.the selected piles. 180 2-7/8" Dia (k - 9)A. Findacapacityof 160 3-1/2" Dia (k - 8)60,000 pounds on the left 140 4-1/2" Dia (k = 7)side of Graph 1 and move 120horizontally to where the 100graph line for 2-7/8 inchdiameter shafts intersects 80with60,000pounds. 60Readdowntodetermine 40thatthemotortorque 20 Earth Contact Productsrequirementis 6,900ft- 0lb. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23T = 6,900 ft-lb, min. Motor Torque x 1000 ft-lbB. Calculating from h tip= 2-3/4 ft(Round up to 3 ft)Equation 2 shows a comparison of results L min= 18+ 3 + 1 ft (specified above grade)between the formula and the graph. L min= 22 feet - Minimum Shaft LengthT = P u/ k, Where, P u= 60,000 lb k = 9 (Table 12) The least amount of shaft needed for this designT = 60,000 lb / 9 ft -1= 6,700 ft-lb is a7footlead,one 7foot andone10footT = 6,700 ft-lb (Not a significant difference) extensionsection(Extensionshaveacoupled6. MinimumEmbedmentDepth. The lengthof 6incheslessthannominallength.)minimum depth requirement from the surface to This is a combined length of 24 feet.the shallowest plate on the pile must be at least 8.TorqueAnchorSpecifications.Thesix times the diameter of the 14 dia. top helical minimum pile assembly shall consist of:plate. (Chapter 1, Equation 9)TAF-288-8410-12-14 2-7/8diameterD=6x(14in/12in/ft)= 7feet 18 standard tubularshaftwith0.276wall(Specified as minimum depth by the engineer.) thickness witha10,a12anda14D mid= 18 mid-plate (Specified) diameter plate on a 7-0 long shaft,7. Minimum Required Shaft Length. HelicalTAE-288W-84 & TAE-288W-120plates are spaced at three times the diameter of extension sections7 & 10 long.the next lower plate.The selected configurationwas 10-12-14.The additional shaft length from If 7,000 ft-lb is not achieved before reaching 24h mid (mid-plate) depthof18ft.tothepiletip feet, then additional extensions may be required.must be determined and added to h mid = 18 feet. End of Example 1Ah tip= [(3 x 10 dia)+(3 x 12 dia)] / 2 = 33Review of Results of Example 1 & 1AThis type of problem may appear when using can see that the result obtained by the Quick -Solveanalysis clearly suggested a larger pile configuration than predicted by the calculations.The Quick -Solve system was designed to be conservative and this example demonstrates this. Thisis a valuable tool to rapidly obtain a preliminary design. It is likely that the 10-12-14 pile design ofExample 1A will reach the required shaft torque at a shallower depth than the 8-10-12 pile. Dependingon the project design, the engineer may require the pile terminate at least 22 feet below grade to meetspecifications. It is possible that the shaft may over torque with the 10-12-14. With the engineerspermission, you could cut off the 10 inch plate and the effective area would equal the 8-10-12.ECP Technical Design ManualTorque Anchor Design Examples2021 Earth Contact Products, L.L.C.2021-09 Chapter 5Page 82 All rights reserved'