b'Design Example 1Corrosion Life of Tubular Torque Anchor Structural and Soil Details: Details are from Design Example 1, Chapter 5ULTIMATE CAP = 60,000 lb New Building2 story house with basement WORKING LOAD = 30,000 lb Estimated weight 3,700 lb/ft Working load on foundation piles30,000 lb TAB-350-NC Top of pile to be 12 above the soil surface. PILE CAP 12" Thesoildatarevealedaleastfivefeetofveryloose sand fill and very soft clay organic soil nearTAE-350-84the surface. EXTENSIONLOOSE SAND FILL Belowapproximatelyfivefeet,alayerofvery WITH VERY SOFTORGANIC SOILstiffinorganicclay(CL),withSPT,N=20 DEPTH 5 FEET\'SPT "N" = 1 TO 3 bpfblowsperfoot(average)existsasstatedin pH = 8.0DesignExample1 inChapter 5andthewater RESISTIVITY = 750table remains at 14 feet - Soil Class = 5 TO 1,000 ohm-cmDifferent corrosive soil data for this example: StandardPenetrationTestvaluesforthisweaklayer were: N = 1 to 3 blows per foot - SoilClass = 8 TAE-350-84EXTENSION Soil pH in the sand fill and soft organic soil wasreportedtobe:pH=8.0andtheresistivity WATERmeasured from 750 to 1,000 ohm-cm to ten feet. TABLE = 14\' The helical Torque Anchor required to support 12"theloadwithoutbuckingintheloosefillwasdetermined to be TAF-350-84 08-10-12 TAF-350-84 08-10-12LEAD SECTION MINIMUMPRODUCTECP Corrosion Life Analysis: The equations LENGTHprovided in the previous chapter will be applied L = 24\'HOMOGENOUSto estimate the average life expectancy of the hot SANDDEPTH = 30\'dip galvanization and a time for a corrosion loss 10" DENSITY = 120 pcfof10%ofwallthicknessofthe3-1/2inch DEG.diameter pile shaft.The results from this analysis provide an estimateof average life expectancy.When dealing withsoilconditionsonajobsite,thereisalwaysa 8"degreeofvariabilityintheperformancelifeofsteel piles.In general, the following can affect to corrode only 10% of wall thickness of the pilethe life of the pile in the soil: shaft after the galvanized coating is exhausted.Sketch for Design Example 1 Multiple strata nature of foundation soils 1.CorrosionEvaluationoftheGalvanized Variability within the soil stratum Coating: A soil study of the jobsite revealed that Variability of the water content of soil both theupperstratumofsoilhas Standardvertically and seasonally Penetration Test (SPT) - N = 1 to 3 blows per Presence or absence of salt ions in the soil foot,thepH=8.0andthesoilresistivitytoadue to leaching, etc. depth of ten feet ranges from 750 to 1,000 ohm- Non-uniformityofthegalvanizedcoating cm.thickness and areas of stress concentration A Corrosivity Score for the soil on this site was Imperfections in the steel determinedtobe10.(SeeTables3&4in Presence of stray currents Chapter8)Thissuggeststhatthesoilbeconsideredtobe AggressivelyCorrosive.ThisThisanalysisconsiderstheperformancelifeof corrosionpotentialraisesaconcernaboutthe galvanized coat along with the time required corrosion effects on the useful life of the helicalpile at this site.ECP Technical Design ManualCorrosion Life Design Examples2021 Earth Contact Products, L.L.C.2021-09 Chapter 9Page 160 All rights reserved'