Settlement Analysis

Formulas

Volume of the Annulus Per Unit Length:

borediameter = Internal Diameter of the Borehole (inch)
Pipediameter = Outside Diameter of the Product Pipe (inch)

Corrected Volume of the Annulus Per Unit Length:

𝑆𝑒𝑡𝑡𝑙𝑒𝑚𝑒𝑛𝑡𝑣𝑜𝑙𝑢𝑚𝑒 = 𝑎𝑛𝑛𝑢𝑙𝑢𝑠𝑣𝑜𝑙𝑢𝑚𝑒 • 𝑉𝑜𝑙𝑢𝑚𝑒𝑓𝑎𝑐𝑡𝑜𝑟

Volumefactor = Volume Correction Factor

Settlement Trough Half Width:

depthborecrown = Depth of Borehole above Crown of the Bore (ft)
θsoil = Internal Friction Angle of Soil (degree)

Settlement Trough Depth at Centerline:

Corrected Settlement Trough Depth at Centerline:

Input Parameters

  • Depth of Borehole above Crown of the Bore [ft]
  • Internal Diameter of the Borehole [inch]
  • Outside Diameter of the Product Pipe [inch]
  • Internal Friction Angle of Soil [degree]
  • Borehole Volume Correction Factor

Outputs/Reports

  • Volume of the Annulus Per Unit Length [inch2]
  • Corrected Volume of the Annulus Per Unit Length [inch2]
  • Settlement Trough Half Width [ft]
  • Settlement Trough Depth at Centerline [ft]
  • Corrected Settlement Trough Depth at Centerline [ft]

Related Links

Horizontal Directional Drilling Miscellaneous