initial information****this should be used together with Steel Pipeline Crossing Railroad and Highways Seventh Edition, Dec 2007 published by APIPipe and operational characteristicsvaluesunitsOutside diameter D12.75inOperating Pressurep1000psiSteel GradeX42Specific Minimum Yield Strength SMYS42000psiDesign Factor F0.72Longitudinal Joint Factor E1Installationn Temperature T0Maximum or minimum operating Temperature T0Temperature derating Factor T0Wall Thickness tw0.281inInstallation and Site CharacteristicsDepth H6ftBored Diameter Bd14.8inSoil Typeloose sandModulos of Soil Reaction E'0.5ksiResilient Modulos Er10ksiUnit Weight 120lb/ft30.0694444444lb/in3type of longitudinal wielderwDistance og Girth Weld from Track CenterlineLG0ftnumber of tracks 1 or 2Nt2tracksRail Loadinge-80Other Steel PropertiesYoungs Modulus Es30000ksiPoissons Ratio vs0.3Coeffiecient of thermal expansion T0.0000065/F

calculationsStep 1Check allowable Barlow StresspD/2twF*E*T*SMYSpD/2tw=22686.8327402135FETSmys30240okStep 2 Circumferential Stress Due to Earth Loadusing tables to obtainKHe3024figure 3 usetw/D=0.02E=0.5Bc1.09figure 4 useH/Bd =4.9soil typeloose sandEe1.11figure 5 useBd/D=1.16She =KHeBeEeD=3239.50725psiStep 3 Impact Factor, Fi, and Applied Design Surface Pressure, w

Fi1.72Use Figure 7 for railroadsH=6refer to section 4.7.2.2.1w=P/Ap13.9psirailroad loadinge-80Sttep 4 Cyclic Stress

Cyclic Circumferential StressSHr = KHrGHrNHFiw8634.3646368psi

KHr332figure 8 usetw/D0.02Er10GHr0.98figure 9 useD12.75H6

section 4.7.2.2.3 and figure 10Nt2NH1.11Cyclic Longitudinal StressSLR = KLRGLRNLFiw7427.25928

KLR317Figure 11 usetw/D0.02Er10GLR0.98figure 12 useD12.75H6from Section 4.7.2.2.3 and fig. 13Nt2NL1Step 5Circumferential Stress Due to Internal Pressurization, SHiSHi=p(D-tw)/2tw21686.8327402135Step 6Principal Stresses, S1,S2,S3 T0 T0 Es30000 vs0.3 T0.0000065

S1=SHe+SH+SHi32353.5992702135S2=SLH-EsT(T2-T1)+vs(SHe+SHi)14905.1612770641S3=-p-1000Seff=[0,5((S1-S2)2+(S2-S3)2+(S3-S1)2]0,528895.3692477548Allowable Effective Stress = F x SMYS30240Step 7Check FatigueGirth WeldsFrom table 3 useSLr/NL or RFSLr/NL=7427.25928SFG=12000RF1SFG x F=12000Longitudinal WeldsFrom Table 3SHr/Nh7778.70688SFL=21000F=0.72SFL x F=15120

tablesCRITICAL AXLE CONFIGURATIONS FOR DESIGN WHELL LOADS OF PS=12Kips (53.4kN) and Pt= 10 Kips(44.5kN)

Depth of burial, H