## 3 Experimental and Numerical Procedures
### Numerical Modeling
The \(q_{b0}\) with various PI was satisfactorily predicted by [PERSON] (1963)'s equation. The \(q_{b0}\) decreased in a polynomial function as the PI increased:  
\[q_{b0}=0.0011\ (\text{PI})^{2}-0.658\ (\text{PI})+255.28\ \text{for}\ 0\%<\text{PI}<314\% \tag{5}\]  
Load-Bearing Capacity of B0 Mixture Reinforced with Horizontal Planar Geotextile Reinforcement with N Layers (Series B)  
Series B-1 to B-3 were carried out on the strip foundation on the B0 mixture reinforced with single horizontal planar layer (Series B-1 and B-2) and two horizontal planar layers (Series B-3) of geotextile reinforcement. The ratios of U/B, W/B and H/B were varied to obtain the optimum values. Series B-4 was for the B0 mixture reinforced with various layers of horizontal planar geotextile (N = 1 to 5) at constant ratio of U/B, W/B and H/B. Figure 6: Relationship between the bearing stress and settlement ration (S/B) of different unreinforced soils. Figure 7: Relationship between bearing capacity and plasticity index (PI) of tested soils. Figure 8 shows the relationships between the \(q_{b}\) and settlement ratio with various values of U/B, W/B, H/B and N. Figure 9 shows the variations of the \(q_{b}\)/\(q_{b0}\). For Series B-1, the measured \(q_{b}\) of B0 reinforced with the single-layer planar geotextile at various U/B ratios and the W/B ratio of 6.0 is shown in Figure 8a. The bearing stress, \(q\), increased when increasing the S/B ratio up to the S/B ratio of approximately 5% and then the \(q_{b}\) was essentially constant with the increased S/B ratio. Figure 9a shows the \(q_{b}\)/\(q_{b0}\) and U/B relationship. The maximum \(q_{b}\)/\(q_{b0}\) ratio was 1.39 at the U/B = 0.30. When the U/B > 1, the \(q_{b}\)/\(q_{b0}\) ratios were approximately equal to 1.0. In other words, the installation of reinforcement deeper than B did not improve the \(q_{b}\). [PERSON] et al. [2] stated that the decrease  
Figure 8: Relationship between bearing stress and S/B ratio with various parameters of (**a**) U/B; (**b**) W/B; (**c**) H/B; and (**d**) N.  
Figure 9: Relationship between bearing stress and S/B ratio with various parameters of (**a**) U/B; (**b**) W/B; (**c**) H/B; and (**d**) N.  
in \(q_{b}\) when U/B < 0.3 was due to the lack of confinement for the top reinforcing layer. While, when U/B > 1, the failure surface in the soil is located above the top of reinforcement layer. For Series B-2, Figures 8b and 9b show the measured \(q_{b}\) and \(q_{b}/q_{b0}\) of B0 reinforced with N = 1 at a constant U/B ratio of 0.3 with various W/B ratios, respectively. For S/B = 0 to 5%, the slope of \(q\) versus S/B plots increased with the increased W/B (Figure 8b). The \(q\) of all the W/B ratios became approximately constant when S/B > 5%. Figure 9b revealed that the \(q_{b}/q_{b0}\) increased as the W/B ratio increased. [PERSON] et al. [40] suggested that the W/B ratio of 6.0 was optimal for a strip footing on sand supported by horizontal planar geosynthtic reinforcement, which is not applicable for the field projects, which with have a limited construction area. In this study, the full-wraparound geotextile reinforcement technique was investigated to reduce the reinforcement width. The W/B = 3.0 was therefore selected for Series C, D, E and F.  
The \(q_{b}\) and \(q_{b}/q_{b0}\) of B0 reinforced with N = 2 at a constant ratio of U/B = 0.3 and W/B = 3.0 with various H/B ratios are shown in Figures 8c and 9c (Series B-3). The \(q_{b}/q_{b0}\) increased with the H/B increased from 0.1 to 0.5. Subsequently, the \(q_{b}/q_{b0}\) decreased when H/B > 0.5. Figures 8d and 9d show the simulated result for Series B-4 with N =1 to 5, U/B = 0.3, W/B = 3.0, and H/B = 0.5. The S/B ratios at the failure increased from 4 to 10% for N increasing from 1 to 5, while the same gradient of \(q\) versus S/B relationship is noted (Figure 8d). Figure 9d shows that the \(q_{b}\) value significantly increased with increasing the N value when N < 4. In other words, the most effective N was 4.