## 3 Results Analysis and Discussion
For all reinforcement lengths and percentages, the BCR increased at Dr = 50% by 53-135% from depth B to 2B and by \(-\)1.5-18% from 2B to 3B. The ultimate bearing capacity did not rise by the same proportion when the reinforcement depth was increased from 2B to 3B at Dr = 50%. Especially in the experimental group with Dr = 50%, Fl = 48 mm, Fc = 2% macromesh fiber additives, when the depth was increased from 2B to 3B, there was no increase in the bearing capacity. In both relative densities, an increase in bearing capacity was observed with increasing fiber length. The soil group, which is reinforced at depth B with Fc = 2% and examined at 30% relative density, has had the highest increase. In both relative densities, an increase in bearing capacity was observed with increasing fiber percentage. * In basalt fiber-reinforced soils, the highest ultimate bearing capacity (q\({}_{\text{u}}\)) was determined as 467 kPa in the case of adding basalt fiber to the sand at Dr = 50%, Fc = 2%, Fl = 24 mm, and 3B reinforcement depth. The highest BCR was determined as 7.5 by adding basalt fiber to sand at Dr = 30%, Fc = 2%, Fl = 24 mm, 3B reinforcement depth. * At both relative densities, the increase in bearing capacity is greater when reinforcement depth is increased from B to 2B. However, the impact on the ultimate bearing capacity of increasing the reinforcement depth from 2B to 3B at Dr = 50% is less significant than the percentage increase seen at Dr = 30%. The average base pressure-settlement curves obtained according to different fiber lengths, different fiber contents, and different reinforcement layer depths as a result of model loading tests on sand soil randomly reinforced with glass + macromesh fiber at Dr = 30% and Dr = 50% are shown in Figure 11, and the reinforcement depth-bearing capacity ratio relationship is given in Figure 12.  
Figure 11: _Cont._  
Figure 10: Variation of bearing capacity ratio (BCR) with reinforcement depth (Dr = 30–50%, Fl = 24 mm, Fc = 1–2%, and basalt fiber). * In glass and macromesh fiber reinforced soils, the highest ultimate bearing capacity (q\({}_{\text{u}}\)) was determined as 580 kPa in the case of adding glass + macromesh fiber to the sand at Dr = 50%, Fc = 2%, Fl = 48 mm, and 3B reinforcement depth. The highest BCR was determined as 8.5 by adding glass + macromesh fiber to sand at Dr = 30%, Fc = 2%, Fl = 48 mm, 3B reinforcement depth. * At 30% relative density, constant fiber content, and constant reinforcement depth, when the fiber length increases from 24 mm to 48 mm, the group with the highest increase in bearing capacity ratio is the group reinforced with glass + macromesh fiber in 3B reinforcement depth with 1% fiber content, and the rate of bearing capacity increased by 41%. * When the soil layer depth reinforced at 30% relative density passes from 2B depth to 3B depth, the least increase in bearing capacity was observed in the 24 mm long 2% fiber-reinforced test. In both relative densities, the highest bearing strength was observed in the 48 mm long soil sample with 2% fiber reinforcement. There is almost no difference between the increase in bearing capacity as a result of improvement  
Figure 11: Average base pressure-settlement curves obtained as a result of model tests on sand soil randomly reinforced with glass + macromesh fiber: (**a**) Dr = 30%, Fl = 24 mm; (**b**) Dr = 30%, Fl = 48 mm; (**c**) Dr = 50%, Fl = 24 mm; (**d**) Dr = 50%, Fl = 48 mm. Figure 12: Variation of bearing capacity ratio (BCR) with reinforcement depth (Dr = 30–50%, Fl = 24–48 mm, Fc = 1–2%, glass and macromesh fiber). in 2B depth and 3B depth in 2% fiber-reinforced soil with a length of 48 mm at 50% relative density.