b'Design Example 2Light Weight New ConstructionCohesive SoilStructural Details: New buildingsingle story brick veneer house onmonolithic concrete slab on grade The estimatedweight is 1,269 lb/lineal ft on the18 tall steel reinforced perimeter beam TheclientwantsTorqueAnchorsontheperimeter of the structure because of lot fill. Top of shaft to be one foot below soil surface Soil data:4 feet of poorly compacted fillN = 56 feet of silty clay (CH)N = 5 to 715 feet of very stiff clay (CL) N= 25 to 30 bpfTorque Anchor Design:1. Select suitable pile spacing and working load ULT. CAP = 17,766 lbfromthedescriptionofthefoundationbeam. WORKING LOAD = 8,883 lbUse Equation 3 from Chapter 1 to determine theworkingloadonthehelicalpile. FirstrefertoGraph 2 -Chapter6todeterminerecommendedPOORLYspacing for an 18 beam.Choose X = 7 ft TAB-150- COMPACTEDNC 1/2 (6x6) FILLP u= (X) x (w) x (FS): PILE CAP DEPTH = 4\'Where,P u= Ultimate Capacity of Torque Anchor (lb)w = Foundation Load (lb/ft) TAE-150-84 SOFT SILTY CLAY= 1,269 lb/lineal foot EXTENSION DEPTH = 6\'FS = 2.0X = Suggested Product Spacing = 7 ft MINIMUMPRODUCTP u= 1,269 lb/ft x 7 ft x 2.0 LENGTHSTIFF SILTY CLAYP u= 17,766 lb (Use 18,000 lb.) DEPTH = 15\' L = 18\'DENSITY = 120 pcfP u= 18,000 lb SPT - "N" = 12 - 162. Select the proper ultimate capacity equationand collect the known information. Because the 8"soil on the site is cohesive (clay soil), Equation 1afrom Chapter 1 is used: TAF-150-60 08-08LEAD SECTIONA H= P u/ (9c) Where:P u= 18,000 lb 10" LENGTH TO EMBEDc = 3,400 lb/ft 2(Assume N = 27 bpf) HELICAL PLATESA H= P u/ (9 x 3,400) S = 3 x (8") = 24"A H= 18,000 lb / 30,600 lb/ft 2 Figure 8.Design Example 2A H= 0.59 ft 23.SelecttheECPHelicalTorqueAnchorsolidsquareshafthasaplateareaof0.87ft 2 .suitable to support the load. The requirement The designation is TAF-150-60 08-10. Referringstatesanultimatecompressivecapacityof to Table 10 from Chapter 1 (next page), we can18,000 lb.Referring to Table 2 in Chapter 1, the manually select a combination of plates along therow to the right of the 1-1/2 square shaft size.1-1/2solid squarepile shaftisaneconomical Atleast0.59ft 2 ofbearingareaisrequiredchoice because it has an Axial Compressive Load according to Step 2.Limitratingof70,000poundsanda UseableTorsional Strength of 7,000 ft-lbs. The combination of 8 & 10 inch diameter platesLooking at the product tables in Chapter 1, Page on the 1-1/2 solid square shaft is selected.6 following Table 2 one can easily see that an 8 A H= 0.333 + 0.533 = 0.87 ft 2 0.59 ft 2 - O.K.and a 10 diameter helical plate on a 1-1/2 inchECP Technical Design ManualTorque Anchor Design Examples2021 Earth Contact Products, L.L.C.2021-09 Chapter 5Page 85 All rights reserved'