b'Likewise, soil Class 8 was not represented in the stable soil stratum underlying these undesirablegraphsbecause Class8soilsusuallycontain strata.significant amounts of organics or fill materials. It is also important to understand that the GraphsThe organics may continue to decay and/or soil 2 through 5 below do not take into considerationwithorganicsand/orfillmaynotbeproperly the installationsoilfrictionoftheshafttypeconsolidatedandarethereforenotconsidered being used with the helical plate configurations.suitable for long term support. As a result, these graphs could suggest holdingGraphs 2 through 5 presented here also show a capacitieswellabovetheUseableTorsionalshaded area for Class 7 soils and part of Class 6 Capacity of the helical shafts shown in Table 2.soils.This is to alert the user that, in some cases, Where the graph line is truncated at the top ofsoilsthatfallwithintheseshadedareasofthe thegraphforaparticularhelicalplategraphsmaynotberobustenoughtosupport configuration, one should not try to extrapolate aheavyloads.Ifthesoilintheshadedareas highercapacitythanindicatedbythetoplinecontain fill; the fill could contain rocks, cobbles, because these plate configurations have reachedtrash,and/orconstructiondebris.Inaddition, theultimatemechanicalcapacityforthatthese soils may not be fully consolidated and/or particularconfigurationbeingrepresented.Itcould contain organic components.Any of these mightbepossibletoachievehighercapacitiescouldallowforcreepofafoundationelement withagivenconfigurationpresentedintheembedded within the stratum.This could cause graphsifoneordersthe TorqueAnchor withaseriousproblemforpermanentorcritical installations.Whensuchweaksoilsare one-half inch thick helical plates instead of theencountered, it is strongly recommended that the standardthree-eighthsinch thickness.Pleaseanchororpilebedrivendeepersothatthe check with ECP or your engineer to determine ifTorque Anchor will penetrate beyond all weak usingthickerhelicalplatescouldachieveaand possibly unstable soil into a more robust and higherultimatecapacityrequirementonaparticular project.Table 9. SOIL CLASSIFICATIONSStandardClass Soil Description Geological Classification Penetration TestRange -N(Blows per foot)0 Solid Hard Rock (Unweathered) Granite; Basalt; Massive No penetrationSedimentary1 Very dense/cemented sands; Coarse Caliche 60 to 100+gravel and cobbles2 Dense fine sands; very hard silts and/or Basal till; Boulder clay; Caliche; 45 to 60clays Weathered laminated rock3 Dense sands/gravel, hard silt and clay Glacial till; Weathered shale; 35 to 50Schist, Gneiss; Siltstone4 Medium dense sand/sandy gravels; very Glacial till; Hardpan; Marl 24 to 40stiff /hard silt/clay5 Medium dense coarse sand and sandy Saprolites; Residual soil 14 to 25gravel; Stiff/very stiff silt and clay6 Loose/medium dense fine/coarse sand; Dense hydraulic fill; Compacted fill; 7 to 15Stiff clay and silt Residual soil7 Loose fine sand; soft/medium clay; Fill Flood plain soil; Lake clay; Adobe; 4 to 8Clay gumbo; Fill8 Peat, Organic silts, Fly ash, Very loose Unconsolidated fill; Swamp WOH to 5sand; Very soft/soft clay deposits; Marsh soil (WOH = Weight of Hammer)Notes:1. Soils in class 0, class 1 and a portion of class 2 are generally not suitable for tieback anchorage becausethe helical plates are unable to advance into the very dense/hard soil or rock sufficiently for anchorage.2. When installing anchors into soils classified from 7 and 8, it is advisable to continue the installation deeperinto more dense soil classified between 3 and 5 to prevent creep and enhanced anchor capacity.3. Shaft buckling must be considered when designing compressive anchors that pass through Class 8 soils.ECP Helical Torque Anchors Technical Service Manual2021 Earth Contact Products, L.L.C.2021-09 Chapter 1 - Page 23 All rights reserve'