## 2 Background: Classification, Drainage Analysis and State Parameter Assessment
### Drainage Analysis  
The classification introduced by [PERSON], [PERSON] and [PERSON] [28; 29; 30] further encompasses a differentiation in terms of drainage conditions. The method delineates a zone of partial drainage conditions by assuming 10 \(<\) Q\({}_{\text{lm}}\) \(<\) 50, which designates Q\({}_{\text{lm}}\) \(<\) 10 as an undrained zone and identifies Q\({}_{\text{lm}}\) \(>\) 50 as a fully drained zone.  
Figure 1: Classification methodology adapted from [PERSON], [PERSON] and [PERSON] [28; 29; 30], clearly distinguishing between plastic and non-plastic soils while simultaneously evaluating drainage conditions.  
Additionally, other parameters, like the pore pressure ratio (Bq) and the normalized penetration velocity (V), are employed to assess drainage conditions.  
Regarding the pore pressure ratio (Bq), [PERSON] and [PERSON] [32] defined a threshold of 0 to establish full drainage, thereby classifying Bq < 0 as indicative of full drainage conditions. Meanwhile, [PERSON], [PERSON] and [PERSON] [25] determined in their study that Bq > 0.5 means a non-drained state for bauxite tailings. Consequently, the range between these two benchmarks could suggest a scenario of partial drainage conditions. Bq can be estimated as follows [33]:  
\[\text{Bq}=\frac{(\text{u}-\text{u}_{0})}{(\text{q}_{\text{t}}-\sigma_{\text{vo }})} \tag{2}\]  
where the u variable represents the excess of pore pressure, and u0 is the hydrostatic water pressure.  
Regarding the dimensionless normalized penetration velocity parameter (V), a fully drained condition is characterized when V falls within the range of less than 0.01 to 0.03, while an undrained penetration state is indicated when V exceeds 30 to 100 [34]. The calculation of V can be achieved using Equation (3):  
\[\text{V}=\frac{\text{v}\times\text{d}}{\text{c}_{\text{v}}} \tag{3}\]  
where v is the cone penetration velocity, d represents the cone diameter, and cv is the vertical consolidation coefficient that can be obtained from dissipation tests.  
In this study, the three parameters (Bq, Qm and V) obtained after SCPTu results were investigated in terms of drainage conditions. Even though Bq and Qm can be calculated for each row of SCPTu results, the parameter V can only be calculated when dissipation tests are performed.  
To address the effects of partial drainage conditions, [PERSON], [PERSON] and [PERSON] [29,30] proposed a methodology to correct qq20 (standard cone tip resistance) obtained in CPTu tests. The authors proposed the following equation to assess the effects of partial drainage conditions:  
\[\frac{\text{q}_{\text{tD}}}{\text{q}_{\text{tD}}}=1+\left(1+\frac{\text{q}_{ \text{tD}}}{\text{q}_{\text{tUD}}}\right)\times\left(\text{B}_{\text{q}} \right)^{0.5} \tag{4}\]  
where qtD is the drained cone tip resistance and qtUD represents the undrained cone tip resistance. The ratio qtD/qtUD assumes a fixed value based on the material's friction angle obtained from triaxial tests (Figure 2).  
Figure 2: Correlation between the qtD/qtUD ratio and the friction angle (\(\phi\)) obtained from triaxial tests. The friction angle value can be used to approximate the qtD/qtUD ratio, consequently facilitating the correction of qtD through Equation (4). The shaded region in gray highlights a range of variations documented in the literature. The listed references can be found in [PERSON], [PERSON] and [PERSON] [35].