In order to enter data required for Becker penetration test processing, you need to enter the following sections:

 

Correlation Method: Choose from the following methods from the following list:

  • Alex Sy and Campanella, 1993b (takes casing friction in to account)
  • Harder and Seed, 1986 (does not take casing friction in to account)

See references for detailed description of each method.

 

Casing Friction: The following options are available:

  • In-situ Measurements: You need to enter casing friction measurements. NovoBPT will apply linear interpolation between readings. If this options is selected, user must enter weight of drill bit and weight of casing per unit length.
  • No Friction: This option is only applicable to Harder and Seed, 1986method.
  • Sandy Material (Alex Sy, 1997): Friction is estimated based on Alex Sy, 1997 proposed equation Rs = 9.7 * Z where Z is depth in metres and Rs is friction is in kPa.
  • Gravelly Material (Alex Sy, 1997): Friction is estimated based on Alex Sy, 1997 proposed equation Rs = Z + 25 * √Z where Z is depth in metres and Rs is friction is in kPa.


BPT Data: Enter Becker penetration test data in the table. This comprise depth, BPT blow counts and pressure readings. If friction is measured at specific depths, enter the friction in corresponding cells and leave the rest of cells in friction column empty. NovoBPT will automatically interpolate frictions in other depths. Then at each depth, net friction is calculated as below:

 

'Net Friction' = 'Measured Friction - ('Weight of Bit' + 'Weight of Scale Coupler' + 'Weight of Casing Per Unit Length' * Z)