# A Practical Group Symbol and Group Name Approach (PSNA) according to EN ISO 14688-2:2018
## 4 PSNA v.1.0 Excel Macro for Practical Soil Marking Approach
The group symbol of the soil particle is determined by the intersection of these three points. Nevertheless, it is evident from the triangular diagram that it is insufficient to merely classify and mark the group symbol. For this purpose, if a coarse material has less  
Figure 6: (**a**) Triangular diagram, (**b**) Plasticity chart, (**c**) C\({}_{\text{u}}\)-C\({}_{\text{c}}\) chart. than 5% fine particles, only the C\({}_{\rm u}\)-C\({}_{\rm c}\) chart is used in addition to the triangular diagram. Currently, the plasticity chart is not displayed within the Excel macro. If the fine particle is more than 12% in terms of coarse material and fine materials, a plasticity chart is used in addition to the triangular diagram. Currently, the C\({}_{\rm u}\)-C\({}_{\rm c}\) chart is not displayed within the Excel macro. If the fine particle concentration is between 5-12% in coarse material, both the C\({}_{\rm u}\)-C\({}_{\rm c}\) chart and plasticity chart are used together in addition to the triangular diagram. Currently, two charts are displayed within the Excel macro. A triangular diagram was also proposed in the withdrawn version of EN ISO 14688-2:2004 [17] but it was based on grading alone (Figure 8). The classification methodology using the triangular diagram did not consider the plasticity chart in EN ISO 14688-2:2004. This diagram was insufficient to help in the classification. EN ISO 14688-2:2018 [21] does not include a triangular diagram. In this study, because of the practicality and readability of a triangular diagram, a novel diagram was developed. All the boundary percentages between particle sizes and  
Figure 8: Triangular diagram of withdrawn standard, EN ISO 14688-2:2004 [17]. Figure 9: The soil identification for Soil 1. Figure 11: The soil identification for Soil 3. Figure 12: The soil identification for Soil 4. Figure 10: The soil identification for Soil 2. Figure 14: The soil identification for Soil 6. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c} \hline \hline
**Soil** & \begin{tabular}{c} **Gravels** \\ **\%** \\ \end{tabular} & \begin{tabular}{c} **Sands** \\ **\%** \\ \end{tabular} & \begin{tabular}{c} **Fines** \\ **\%** \\ \end{tabular} & \begin{tabular}{c} **D\({}_{10}\)** \\ \end{tabular} & \begin{tabular}{c} **D\({}_{30}\)** \\ \end{tabular} & \begin{tabular}{c} **D\({}_{60}\)** \\ \end{tabular} & \begin{tabular}{c} **C\({}_{\text{c}}\)** \\ \end{tabular} & \begin{tabular}{c} **C\({}_{\text{u}}\)** \\ \end{tabular} & \begin{tabular}{c} **LL \%** \\ \end{tabular} & \begin{tabular}{c} **PL\%** \\ \end{tabular} & \begin{tabular}{c} **PI\%** \\ \end{tabular} & \begin{tabular}{c} **PI\%** \\ \end{tabular} & \
\begin{tabular}{c} **Group** \\ **Symbol** \\ \end{tabular} &
\begin{tabular}{c} **Group Name** \\ \end{tabular} \\ \hline
1 & 10 & 83 & 7 & 0.15 & 0.4 & 2.0 & 0.53 & 13.33 & 30 & 15 & 15 & SaM\(-\)SaCl &
\begin{tabular}{c} Medium Graded \\ Sand with Clay \\ \end{tabular} \\ \hline
2 & 45 & 30 & 25 & & & & & 45 & 25 & 20 & GrCl &
\begin{tabular}{c} Clayev \\ with Sand \\ \end{tabular} \\ \hline
3 & 10 & 33 & 57 & & & & & 60 & 28 & 32 & CIH &
\begin{tabular}{c} Sandy, High \\ Plasticity Clay \\ \end{tabular} \\ \hline
4 & 15 & 8 & 77 & & & & & 55 & 40 & 15 & SiH &
\begin{tabular}{c} High Plasticity \\ Sil with Gravel \\ \end{tabular} \\ \hline
5 & 7 & 6 & 87 & & & & & 90 & 30 & 60 &
\begin{tabular}{c} Very High \\ Plasticity Clay \\ \end{tabular} \\ \hline
6 & 75 & 21 & 4 & 1.1 & 1.2 & 1.9 & 0.69 & 1.73 & & & &
\begin{tabular}{c} Uniformly \\ Graded Gravel \\ with Sand \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Examples of the soil marking group name and group symbols of PSNA v.1.0. Figure 13: The soil identification for Soil 5.