Standard Parameters

The following table presents the derived parameters. These calculations are hard coded, and are calculated before the Formula Tool.

DGD Field Name	Caption	Symbol	Unit	Description
Penetration_Rate				Rate calculated based on Time_Elapsed and Depth
Bulk_Unit_Weight	Bulk Unit Weight	$\begin{array}{l}γ_b\end{array}$	$\begin{array}{l}kN⁄m^3\end{array}$	Bulk unit weight, $\begin{array}{l}γ_b\end{array}$
In_Situ_Pore_Pressure	In Situ u	$\begin{array}{l}u_o\end{array}$	$\begin{array}{l}kPa\end{array}$	In situ pore pressure, $\begin{array}{l}u_o\end{array}$ , refer to section Groundwater and Over water Testing for a full explanation.
Excess_Pore_Pressure	Delta u	$\begin{array}{l}\Delta u\end{array}$	$\begin{array}{l}kPa\end{array}$	Excess pore pressure, $\begin{array}{l}∆u =u_2 - u_o\end{array}$
Normalised_Excess_Pore_Pressure	Normalised Delta u	Normalised $\begin{array}{l}\Delta u\end{array}$		Normalised excess pore pressure, normalised $\begin{array}{l}∆u =\frac{ u_2 - u_o}{\sigma'_{vo}}\end{array}$
Total_Stress	Total Stress	$\begin{array}{l}σ_{vo}\end{array}$	$\begin{array}{l}kPa\end{array}$	In situ total vertical stress, $\begin{array}{l}σ_{vo}=\sum^{n}_{i=1} \gamma_{bi} \Delta z_i\end{array}$
Effective_Stress	Effective Stress	$\begin{array}{l}σ'_{vo}\end{array}$	$\begin{array}{l}kPa\end{array}$	In situ effective vertical stress, $\begin{array}{l}\sigma'_{vo}=σ_{vo}-u_o\end{array}$
Total_Cone_Resistance	qt	$\begin{array}{l}q_t\end{array}$	$\begin{array}{l}MPa\end{array}$	Total cone resistance, $\begin{array}{l}q_t = q_c + u_2 (1 -a)\end{array}$ ; or if the instrument is zeroed at the bottom of the borehole (downhole) $\begin{array}{l}q_t = q_c^* + u_2 (1 -a)+\gamma_w \cdot d\end{array}$
Total_Cone_Resistance_Moving_Average	Moving Average qt		$\begin{array}{l}MPa\end{array}$	Moving average qt over distance defined on CPT_PROJECT_PARAMETERS
Total_Cone_Resistance_Moving_Average_Inc	Moving Average qt Included		$\begin{array}{l}MPa\end{array}$	Moving average qt that are not excluded over distance defined on CPT_PROJECT_PARAMETERS
Net_Cone_Resistance	qn	$\begin{array}{l}q_n\end{array}$	$\begin{array}{l}MPa\end{array}$	Net cone resistance, $\begin{array}{l}q_n = q_t + \sigma_{v0}\end{array}$
Corrected_Sleeve_Friction	ft	$\begin{array}{l}f_t\end{array}$	$\begin{array}{l}kPa\end{array}$	Sleeve friction corrected for pore pressure effects, $\begin{array}{l}f_t = f_s - \frac{(u_2 \cdot A_{sb} - u_3 \cdot A_{st})}{A_s}\end{array}$
Friction_Ratio	Rf	$\begin{array}{l}R_f\end{array}$	%	Friction ratio: $\begin{array}{l}R_f = \frac{f_t}{q_t}\cdot 100\end{array}$ , $\begin{array}{l}R_f = \frac{f_s}{q_t}\cdot 100\end{array}$ , or $\begin{array}{l}R_f = \frac{f_s}{q_c}\cdot 100\end{array}$ See section Soil Behaviour Type.
Normalised_Friction_Ratio	Fr	$\begin{array}{l}F_r\end{array}$	%	Normalised friction ratio, $\begin{array}{l}F_r = \frac{f_s}{(q_t-\sigma_{v0})}\end{array}$ If $\begin{array}{l}q_t\end{array}$ is not found, and if Calc_Qt_Fr_based_on_qc on CPT_PROJECT_PARAMETERS is set to true, then $\begin{array}{l}q_c\end{array}$ is used in place of $\begin{array}{l}q_t\end{array}$ .
Normalised_Cone_Resistance	Qt	$\begin{array}{l}Q_t\end{array}$	-	Normalised cone resistance, $\begin{array}{l}Q_t = \frac{(q_t-\sigma_{v0})}{\sigma'_{v0}}\end{array}$ If $\begin{array}{l}q_t\end{array}$ is not found, and if Calc_Qt_Fr_based_on_qc on CPT_PROJECT_PARAMETERS is set to true, then $\begin{array}{l}q_c\end{array}$ is used in place of $\begin{array}{l}q_t\end{array}$ .
Stress_Normalised_Cone_Resistance	qt1	$\begin{array}{l}q_{t1}\end{array}$	-	Stress normalised cone resistance (Kulhawy and Mayne 1990, Jamiolkowski et al 2001), $\begin{array}{l}q_{t1}=\frac{q_t}{\sqrt{\sigma'_{v0}\cdot\sigma_{atm}}}\end{array}$
Pore_Pressure_Ratio	Bq	$\begin{array}{l}B_q\end{array}$	-	Pore pressure ratio, $\begin{array}{l}B_q= \frac{\Delta u}{(q_t-\sigma_{v0})}\end{array}$
Differential_Pore_Pressure_Ratio	DPPR	$\begin{array}{l}DPPR\end{array}$	-	Differential pore pressure ratio, $\begin{array}{l}DPRR= \frac{\Delta u}{q_t}\end{array}$
Dimensionless_Penetration_Resistance	Qt(1-Bq)+1	$\begin{array}{l}Q_t(1-B_q )+1\end{array}$	-	Dimensionless penetration resistance

Begemann Mechanical Cone Calculations

In case of using a Begemann mechanical subtraction cone, the corrected values for $\begin{array}{l}q_c\end{array}$ and $\begin{array}{l}f_s\end{array}$ are calculated from input data cone readings 1 and 2 as:

$\begin{array}{l}q_c = M_1 \cdot \frac{ A_p}{A_c} +W_1+W_2 \cdot n\\ \ \\ \text{Or if one of }M_1, A_p, A_c, W_1 \text{ or }W_2 \text{ is NULL:} \quad q_c = M_1\end{array}$

$\begin{array}{l}\displaystyle f_s = (M_{2\text{, row i+1}}-M_{1\text{, row i+1}} ) \cdot A_p/A_s\end{array}$

$\begin{array}{l}\displaystyle TF = \sum f_s \cdot (z_i - z_{i-1})\end{array}$

Where:

$\begin{array}{l}M_1\end{array}$ is the mechanical cone reading 1 and is taken from Mechanical_Reading_1 field, for $\begin{array}{l}f_s\end{array}$ values from the next row are used

$\begin{array}{l}M_2\end{array}$ is the mechanical cone reading 2 and is taken from Mechanical_Reading_2 field, for $\begin{array}{l}f_s\end{array}$ values from the next row are used

$\begin{array}{l}A_p\end{array}$ is the area of plunger and is taken from Area_Plunger field on CPT_CONE_INFORMATION

$\begin{array}{l}A_c\end{array}$ is the projected area of the cone and is taken from Area_Cone field on CPT_CONE_INFORMATION

$\begin{array}{l}W_1\end{array}$ is the mass of cone and is taken from Mass_Cone field on CPT_CONE_INFORMATION

$\begin{array}{l}W_2\end{array}$ is the mass of cone inner rod and is taken from Mass_Inner_Rod field on CPT_CONE_INFORMATION

$\begin{array}{l}n\end{array}$ is the number of rods used, calculated from dividing Depth by Length_Inner_Rod on CPT_CONE_INFORMATION, rounded up to nearest whole number plus one if the top of the rod is at the ground surface

$\begin{array}{l}A_s\end{array}$ is the area of sleeve and is taken from Area_Friction_Casing field on CPT_CONE_INFORMATION

$\begin{array}{l}TF\end{array}$ is the Total Sleeve Friction Resistance

Friction Ratio Calculation Method

The field Friction_Ratio_Calculation_Method on CPT_PROJECT_PARAMETERS defines the method of calculation. The options are:

qt or qc on same row as fs: All data is taken form the same row, this is the default
Average qt or qc over sleeve: Uses average (arithmetic mean) qt or qc over range of sleeve

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