b'Plate Embedment in Tension Applications: overlaying a weak and softer stratum of soil.,When a pile must resist uplift or tension loads, One must consider the possibility that the Torquethe pile must be adequately embedded into the Anchorcouldpunch throughtotheweakerbearing stratum to offer resistance to pull out. soilwhenfullyloadedtoachieveaxialcompressivebearing. Usecaution insituationsThe pile must first qualify as a deep foundation, whendesigningtheTorqueAnchorinanydefinedasbeinginstalledtoadepthfrom competent soil situated directly above a weakerintendedsurfaceelevationofnolessthansix soil stratum.times the diameter of the largest and shallowesthelical plate (6 x d Largest ).In addition, to insure Whendesigningapileinsuchsituations,itisthatthepileisfullyembedded,therequired recommendedthatadistancegreaterthanfiveterminal torsion applied to the shaft must have timesthediameterofthelowest(smallest)been an average of the torsion developed over a helical plate (5 x d Lowest ) must exist below the tipdistance of no less than three times the diameter oftheTorqueAnchortopreventpunchingof the uppermost (largest) plate.L t= 3 x d Largest through intothestratumofweakersoilandPreventing Punch Through: A soil boring possibly failing.on occasion may report a layer of competent soilTieback Design ConsiderationsOne of the most common applications for helical When ECP Helical Torque Anchortiebacks aretiebackanchorsisforsupplementalbasement installed and anchored into the soil; two repairwall support.Many basement walls show signs options are available:ofinwardlybulging,havehorizontaltension 1. The tieback is designed and loaded to supportfractures and/or have rotated inwardly. orsupplementthewallstructure.SoilisnotConsolidationofthefillsoil,inoperativedrain removedfrombehindthewall; therefore,thetiles,plumbingleaks,pondingwateronthe wall can be only supported and not restored.surfacenearthebasementwall,orother 2. The soil behind the wall is removed and theenvironmental factors are largely the cause of the tieback anchor is used to restore the wall to neardistressseen inmanybasementwallfailures. itsoriginalposition.PropergranularmaterialPASSIVE FAILURE ACTIVEPLANES FAILUREPLANEPASSIVE EARTH ACTIVE SOILPRESSURE AREA PRESSURE AREAT UCRITICALEMBEDMENT INSTALLATIONDEPTH - "D" ANGLE TIEBACKLARGEST HELICAL PLACEMENTPLATE DIAMETER = "d" SOIL(MEASURE IN FEET)HEIGHT "H"MINIMUM HELICAL PLATE LATERAL FORCEEMBEDMENT AT THE REQUIRED OF SOIL AGAINSTINSTALLATION TORQUE = "d" x 3 WALL(LARGEST PLATE DIA. x 3)Lo = MINIMUM HORIZONTALEMBEDMENT = H + 10d (ft)(EQUATION 10) EMBEDMENT LENGTH = L / COS(TABLE 13) Figure 3 .ECP Helical Torque Anchors Technical Service Manual2021 Earth Contact Products, L.L.C.Figure 3.Elements of Tieback Design2021-09 Chapter 1 - Page 29 All rights reserve'