b'Design Example 1ACorrosion Life of Tubular Torque Anchor Quick and Rough MethodAll of the structural and soil data is the same as years at 500 ohm-cm and pH = 8.The corrosionstated in Design Example 1 above. life at 1,000 ohm-cm and pH = 8 is 20 years.1. Corrosion Life EstimatedSteel Loss: The An average value can estimate corrosion life atestimated average amount of time for ten percent 750ohm-cmbetween17and20years.TheofthewallthicknessofaTAF-350tubeto average value for steel corrosion life is:corrode can be estimated from Table 5 presented CL P= [17 + 20] years / 2 = 18.5 yearsin Chapter 8, and reproduced below. 2.EstimatedLife GalvanizeLoss: TheManytimestheexactfieldresistivityandpH averagecorrosionlifeofhotdipgalvanizetowill not be found on Table 5.The average life ASTM A123 Grade 75 can be found at the rightwill have to be estimated based from between the column.It is necessary determine the corrosionpH values in the table. lifeat750ohm-cmresistivity,or midwayTheresistivitywasreportedbetween750and between 12 and 15 years:1,000 ohm-cm and the pH is 8. To estimate the CL G= [9 yr (500 -cm)+11 yr (1,000 -cm]/2corrosion life of the pile, it is necessary to find CL G= 10.0 yrsthe pile configuration at the top of the table.Indeterminingcorrosionlife,conservative 3.Determinethecorrosionlifeofthepile.decisions should always be used. The estimated average corrosion life expectancyThespecifiedTAE-350TorqueAnchorshaft ofthesteelpierwheninstalledatthejobsitecan be found at the sixth column from the left. afterallofthegalvanizingisdepletedandtenThere are two sub-tables; resistivity of 500 ohm- percent of the steel has been lost is the sum ofcmand1,000ohm-cm.Avaluehalfway the corrosion values from Steps 1 and 2.between 500 and 1,000 ohm-cm (750 ohm-cm)Life = CL P+ CL G= 18.5 + 10.0 = 28.5 yearswill be used here.The soil pH = 8 is located at Corrosion Life = 28.5 years*the left column.The corrosion life estimate is 17TABLE 5.Sample ECP Torque Anchor & Soil Nail Life Expectancy Estimates at Full LoadPlain Steel Life Expectancy at Full Load Hot Dip GalvanizeSoil 1.7 oz/ft 2 - 3.0 MilspH 1-1/2 1-3/4 2 Square 2-7/8 Dia. x 3-1/2 Dia. x 4-1/2 Dia. xSquare Bar Square Bar Bar 0.262 Tube 0.300 Tube 0.337 Tube (Minimum)Soil Resistivity500 ohm-cm4.5 25 yrs 30 yrs 34 yrs 9 yrs 11 yrs 12 yrs5 100+ yrs 100+ yrs 125+ yrs 48 yrs 57 yrs 63 yrs Add 9 years to8 45 yrs 52 yrs 59 yrs 15 yrs 17 yrs 19 yrs life shown at left10.5 25 yrs 30 yrs 34 yrs 9 yrs 11 yrs 12 yrsSoil Resistivity1,000 ohm-cm 24.5 29 yrs 34 yrs 38 yrs 10 yrs 1 12 yrs 13 yrs .5 100+ yrs 100+ yrs 150+ yrs 57 yrs . 67 yrs 73 yrs Add 11 years to8 49 yrs 57 yrs 65 yrs 17 yrs 20 yrs 22 yrs life shown at left10.5 29 yrs 34 yrs 38 yrs 11 yrs 12 yrs 13 yrsReview of Results of Example 1 & 1A4.5 34 yrs 39 yrs 51 yrs 12 yrs 14 yrs 15 yrsThe result obtained by the Quick -Solve design analysis and the result that was calculated are very similar.5 125+ yrs 125+ yrs 150+ yrs 85 yrs 100 yrs 100+ yrs Add 20 years toLarger differences can occur when making estimates for values that fall between the data boxes with larger8 47 yrs 67 yrs 86 yrs 19 yrs 22 yrs 24 yrs life shown at leftcorrosion lives in the tables.10.5 34 yrs 39 yrs 51 yrs 12 yrs 14 yrs 15 yrs* Onemustbecautionednottoconsidertheresultofeitheranalysisas anexactanswerSoil Resistivity5,000 ohm-cmbecause the formulas were derived from empirical data.Both corrosion lives determined in4.5 45 yrs 52 yrs 67 yrs 16 yrs 18 yrs 20 yrsExample1&1Aareaccuratewithintherangeoferror.Itisadvisedtorounddown theestimated l0+ yrs be conserrs 175+ ase review the Important Notes in Chapter 8.5 15ife to 150+ yvative.Pleyrs 100+ yrs 100+ yrs 100+ yrs Add 34 years to8 82 yrs 95 yrs 100+ yrs 29 yrs 33 yrs 37 yrs life shown at leftECP Technical Design ManualCorrosion Life Design Examples2021 Earth Contact Products, L.L.C.10.5 45 yrs 52 yrs 67 yrs 16 yrs 18 yrs 20 yrs2021-09 Chapter 9Page 162 All rights reserved'