Settlement Analysis

Formulas

Volume of the Annulus Per Unit Length:

bore_diameter = Internal Diameter of the Borehole (inch)
Pipe_diameter = Outside Diameter of the Product Pipe (inch)

Corrected Volume of the Annulus Per Unit Length:

𝑆𝑒𝑡𝑡𝑙𝑒𝑚𝑒𝑛𝑡_{𝑣𝑜𝑙𝑢𝑚𝑒} = 𝑎𝑛𝑛𝑢𝑙𝑢𝑠_{𝑣𝑜𝑙𝑢𝑚𝑒} • 𝑉𝑜𝑙𝑢𝑚𝑒_{𝑓𝑎𝑐𝑡𝑜𝑟}

Volume_factor = Volume Correction Factor

Settlement Trough Half Width:

depth_borecrown = Depth of Borehole above Crown of the Bore (ft)
θ_soil = 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