b'Thetorquemustbedevelopedforadistance L = L 15+ L Tip= 25 ft + 4-1/2 ft = 29-1/2 ftgreat enough to insure that the helical plates are L = 29-1/2 feet min. at= 15 0properlyembeddedto insureadequatetension 6. Torque AnchorCapacity Verification: Acapacity.Theinstallermustaverageatleast 4,900 ft-lbs over a minimum distance of 3 feet. review of Table 2Chapter 1 indicates that the(Three times the 12 diameter plate = 3 ft.) 1-3/4solidsquarebarTorqueAnchorhasa5.SelectInstallationAngleandProduct UltimateLimitTensionStrengthof100,000lbLength. The anchors shall penetrate the wall at and a Useable Torsional Strength of 10,000 ft-lb.3-1/2feetbelowthesoilsurface.(Thisis Theprojectultimatetensioncapacityandapproximately 0.3 times the wall height.) Recall torsional requirement are approximately one-halfthatembedmentdepthwasselectedat10ftin of the mechanical and torsional capacity of theStep 2.This means that the depth below the soil product.There was no mention about rocks,surfacetothelocationofthe12helicalplate debrisorotherobstructionsinthesoilsomustbeatleast10feet.Tryusingan installation should be smooth.A check of Tableinstallationangleof15 anddeterminethe 11 Chapter1indicatesthatthree3/8thick0 helicalplateshaveanultimatecapacityofproductlengththatwillprovidethe10feetof 120,000pounds(3x40,000lb),sothetotalverticalembedmentrequired.(Recallthatthe mechanical capacity of the anchor is satisfactory.distance from the top of grade level to where the 7.TorqueAnchorSpecifications.Theanchors will penetrate the wall is 3-1/2 feet. The required Torque Anchorassembly consists of:additionaldepthrequiredbytheanchorisTAF-175-84 08-10-12 - 1-3/4 solid squaretherefore (10 ft - 3-1/2 ft) = 6-1/2 feet. bar, on a standard 7 long shaft with 8, 10The shaft length required at 15 0to achieve the 6- & 12 dia. plates,1/2footverticaldepthiscalculatedusingtheTAE-175-84extensions -7feetlong&equationgiveninTable13inChapter1foradeclination angle of 15 0 . hardware(6-9effectivelength)ThreeL 15= (6-1/2 ft/sine 15 0 ) = 6-1/2 ft/0.259 = 25 ft extensions are required.Theminimumshaftlengthat15 0 installationTAE-175-60extensions -5longwithangle is 25 feet, which will insure that the 12 hardware(4-9effectivelength)Onediameterplateislocatedatatotalembedment extension is required.depth of 10 feet below the surface.TAB-175 T Tension Pile Cap3/4 x 8 xComparing the Minimum Horizontal Embedment 8 pile cap with bolt and nut.The pile caplengthfromEquation9tothe Minimum boltstotheanchorshaftandwillbeEmbedment Depth (Step 5): incorporatedintothenewconstructionL 0= H + [10 x (d largest /12)] concrete wall.L 0= Minimum Horizontal Embedment Length Theactualassembledlengthofthespecifiedfrom Wall to the Shallowest Plate(ft) Torque Anchor system is 32 ft.H=Height of Soil Against Wall - (ft) The anchors shall mount along the wall at 7 feetd largest= Diameter Of Largest Plate - (ft) center to center and at a vertical distance of 3-1/2L 0= 12 + [10 x 1] = 22 ft. feetfromthetopoftheproposedwall.The ItisclearthatL 15 =25ft(Lengthtoinsure anchors shall be installed at a downward angle ofrequired 10 soil embedment depth determined in 15 0from horizontal.Step5)exceedsthe MinimumHorizontal The tiebacks must be installed to a length greaterEmbedment requirement. than 29-1/2 feetThe 10 ft depth of embedment also exceeds the Theanchormust beinstalledtoanaverageCritical Depth, D = 6 x d 12= 6 x 12/12 = 6 ft installationtorqueof4,900ft-lbormorefor aL 15= 25 L 0 = 22using D = 6 ft minimum distance of at least 3 feet beyond anL 15= 25 ft must be used installed length of 26 feet, if less than 4,900 ft-lb,Minimum Required Shaft Length: the anchor shall be driven deeper until the torqueL = L 15 + L Tip (Distance nearest plate to tip) requirement is satisfied.Where:L Tip= (3 x d plate 1 ) + (3 x d plate 2 ) End of Example 4L Tip= [(3 x 8 dia)+(3 x 10 dia)]/12 = 4-1/2 ftECP Technical Design ManualTorque Anchor Design Examples2021 Earth Contact Products, L.L.C.2021-09 Chapter 5Page 95 All rights reserved'