CALCULATION OF THRUST BLOCK DIMENSIONS FOR HORIZONTAL BENDS

INPUTS

Description Symbol Value Unit

Pipe Diameter D 2000 mm

Working Pressure Pw 10 bar

Deflection Angle 64,3 degree

Burial Depth of Pipe H 2000 mm

Soil Type -Slightly

Compact -

Safety factor 1 (Default value =2,5) FS1 2,5 Dimensionless

Safety factor 2 (Default value =1,5) FS2 1,5 Dimensionless

Effective Soil Density g 19 kN/m3

Required Bearing Surface Length Lf 8,00 mThrust Block Layer Thickness at the Bottom of Pipe H1 500 mmThrust Block Layer Thickness Above Top of Pipe H2 500 mm

1 / 2

CALCULATION OF THRUST BLOCK DIMENSIONS FOR HORIZONTAL BENDS

CALCULATIONSDepth to Bottom of the Thrust Block Hb 4,5 mMid depth of Thrust Block Z 3 mInternal Friction Angle of the soil material f 30 degreeThe lateral stiffness of soil Ky 26,6 kPa/mmAllowable movement for thrust block y 6 mmCoefficient for lateral movement of the soil at ult. bearing strength Cy 0,025 Dimensionlesslateral movement accepted by soil before bearing capacity failure yu 75,00 mmBrinch-Hansen bearing capacity factor Nq 6 DimensionlessBearing strength, the max. stress that the soil will support pu 342 kPa Allowable bearing strength of soil (kPa) p'u 136,8 kPaShear strength of soil acting at the bottom surface of the thrust block tb 49,36 kPaArea of the bottom of the thrust block Ab 23,6 m2Required Bearing Surface Height Hf 3,00 mRequired Bearing Surface Area Af 24,0 m2

FORCESActing ForceHydrostatic Thrust Force Ft 3344 kNActive Lateral Load Capacity of Soil Pa 64 kN/mResistance ForceFrictional Resistance Force at Bottom of Thrust Block Ff 1165,9 kNPassive Lateral Load Capacity of Soil Pp 577,1 kN/m

RESULTSCheck 1 FS1=2,5 < 2,80 OKCheck 2 Ft=3344 kN < 4298,2 OKCheck 3 FS2=1,5 < 1,58 OK

2 / 2