# 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  
In the present study, a macro in Excel called PSNA v.1.0 was developed to mark soils according to PSNA. The macro was created within the Microsoft Excel 2019 software platform, utilizing the integrated programming language known as Visual Basic for Applications (VBA). This macro can be found in the Supplementary Materials. The flow charts that were prepared for PSNA were based on developing PSNA v.1.0. A macro in Excel facilitates the efficient assignment of group symbols and names. For this purpose, sieve openings from \(\geq\)0.063 mm (sieve No. 230) to \(\leq\)75 mm of ASTM E11 sieves [39] were employed in this Excel macro. According to the Excel macro, the user is provided with the option to select the desired sieve opening for implementation. Sieve sizes of 2.00 mm (No. 10) and 0.063 mm (sieve No. 230) are essential boundaries for the marking of soils according to PSNA. In order to conduct a comprehensive comparison between PSNA and ASTM D2487-17e1, it is essential to consider the inclusion of sieve sizes of 4.75 mm (sieve No. 4) and 0.075 mm (sieve No. 200) as mandatory thresholds for soil classification. Also, LL %, PL %, D\({}_{10}\), D\({}_{30}\), and D\({}_{60}\) values are necessary according to PSNA v.1.0. C\({}_{\rm u}\) and C\({}_{\rm c}\) parameters can be calculated automatically using typical grain diameters D\({}_{10}\), D\({}_{30}\), and D\({}_{60}\). If the user prefers, they have the option to input C\({}_{\rm u}\) and C\({}_{\rm c}\) values individually. The particles retained on the sieves should be recorded. Only yellow areas are entered into the macro. If there is no requirement between classification methods, sieve size 2.00 mm (sieve No. 10) and sieve size 0.063 mm (sieve No. 230) can be used. Following this procedure, the group symbol and group name are efficiently established within a matter of seconds using the Excel macro on the table. Additionally, a triangular diagram was developed in the present study to facilitate the interpretation of classification results for users of the PSNA v.1.0 macro. The edges of the triangle were prepared for gravel, sand, and fine particles (Figure 6a). The arrowhead direction indicates the increase in particle percentage. The corners of the triangle are 100% for each particle, e.g., gravel, sand, and fine particles. Figure 6: _Cont._In general, a triangular diagram has an opportunity to display data based on three variables simultaneously. Triangular diagrams are easy to read and create and practical presentations for users. However, the triangular diagram developed in this study cannot classify soil alone because there is more than one group symbol in the same area. Therefore, an additional two charts were also used to overcome this obstacle. One of them was the plasticity chart (Figure 6b) and the other one was the shape of the grading chart (C\({}_{\text{u}}\)-C\({}_{\text{c}}\) chart) (Figure 6c). The shape of the grading chart was developed using C\({}_{\text{u}}\) and C\({}_{\text{c}}\) values in EN ISO 14688-2:2018 (Table 2). According to the ratio of gravel, sand, and fines, a plasticity chart, C\({}_{\text{u}}\)-C\({}_{\text{c}}\) chart, or both were used. Figure 7 presents a visual representation of PSNA v.1.0. To ascertain the location of a specific point within the triangular diagram, the sand ratio is determined on the basis of sand edge or, in other words, on the left side of the triangle. Additionally, a parallel line is drawn from this point toward the fine edge, which corresponds to the base of the triangle. Then, the gravel ratio is determined using the gravel edge or, in other words, the right side of the triangle. Then, a parallel line is drawn from this point to the sand edge or, in other words, to the left side of the triangle. Then, the ratio of the fine is determined on the fine edge or, in other words, the base of the triangle, and a parallel line is drawn from this point to the gravel edge, in other words, to the right side of the triangle.