## 3 Results and Discussions
### Models
#### 3.1.2 Calibrated Models
The quadratic model won in the competition between models for the moist unit weight of fine-grained soils, as represented by Equation (6). The sparse nature of the collected data hinders the effectiveness of the model, resulting in a weak relationship with an R\({}^{2}\) value of 0.16. Consequently, the linear model is also a viable option, although its performance is inferior to that of the quadratic model. \[\gamma_{moistFG}=0.0008\mathrm{N}^{2}+0.0418\mathrm{N}+14.849 \tag{6}\]  
where \(\gamma_{moistFG}\) is the moist unit weight of fine-grained soils (\(\mathrm{kN}/\mathrm{m}^{3}\)), and N is SPT N-value, with a range of 1\(<\) N \(\leq\) 50. The proposed model follows the trend established by previous researchers [20; 48], which establishes a direct correlation between the SPT N-Value and the soil unit weight. [PERSON] et al. [20] explain that this trend is attributable to the compaction of soil particles and the presence of an adequate amount of water in the soil layer above the groundwater table. As the N-Value increases, so does the relative density of the soil particles, resulting in greater compaction and, ultimately, a rise in unit weight. In addition, the saturated unit weight is a distinct parameter used for subsurface soil layers. Above the groundwater table, soil particles are not saturated with water, resulting in a higher unit weight. However, the trained models contradict this notion because most saturated soil layers are located below the groundwater table and are denser, accounting for the additional weight of water due to its saturation in this property. Therefore, these soil layers tend to have a higher unit weight, with a minimum of 15.63 \(\mathrm{kN}/\mathrm{m}^{3}\) and a maximum of 21.53 \(\mathrm{kN}/\mathrm{m}^{3}\) for the saturated unit weight. The linear model is the preferred and most accurate model for estimating the saturated unit weight of both coarse-grained and fine-grained soil layers. With an R\({}^{2}\) value of 0.30, the linear model for coarse-grained soil has a moderately positive relationship. The linear model for fine-grained soil, on the other hand, has a strong positive relationship, with an R2 value of 0.61. The coarse-grained soil model has a lower R\({}^{2}\) value than the fine-grained soil model, indicating that there is less sparsity in the data. The model for the saturated unit weight of coarse-grained soils is represented by Equation (7), while the model for the saturated unit weight of fine-grained soils is represented by Equation (8). Based on the trend described by previous studies [49; 50; 51; 52] a linear relationship can be estimated between the SPT N-Value and the saturated unit weight. Given the SPT N-value, it is possible to determine the saturated unit weight of a soil layer. \[\gamma_{satCG}=0.1197\mathrm{N}+15.454 \tag{7}\]  
\[\gamma_{satFG}=0.0998\mathrm{N}+15.531 \tag{8}\]where \(\gamma_{satCG}\) is the saturated unit weight of coarse-grained soils (kN/m\({}^{3}\)), \(\gamma_{satFG}\) is the saturated unit weight of fine-grained soils (kN/m\({}^{3}\)), and N is SPT N-value, with a range of 1\(\times\) N \(\leq\) 50. The equations (Equations (4)-(8)) for the unit weight of soil layers are restricted to the range of SPT N-values between 1 and 50. Values greater than 50 are indicative of refusal (rocks). Soil liquefaction is the phenomenon in which saturated soil loses its strength when subjected to an external force, such as an earthquake. Peak ground acceleration (PGA) is an essential factor in determining the likelihood of soil liquefaction, as it measures the maximum acceleration that the ground reaches during an earthquake. This parameter is directly correlated with the amount of ground shaking during an earthquake. The greater the PGA, the greater the probability of soil liquefaction. In engineering analysis and design of structures against liquefaction, PGA is typically employed as an input variable via cyclic stress ratio (CSR).