## 3 Results Analysis and Discussion
### The Effect of Different Fiber Additives on Soil Behavior  
The graphs obtained within the scope of the study as a result of evaluating together the different fiber types (glass, basalt, and macromesh fiber), hybrid fiber (glass + basalt, glass + macromesh, basalt + macromesh, and glass + basalt + macromesh fiber), fiber length (Fl = 24 mm and Fl = 48 mm), fiber content (Fc = 1% and Fc = 2%), relative density (Dr = 30% and Dr = 50%) and reinforcement depth (B, 2B and 3B) is given in Figures 19 and 20. The BCR values obtained as a result of the tests are also given in Table 5.  
Figure 19: Reinforcement depth-ultimate bearing capacity relationship corresponding to fiber type in tests with Dr = 30% relative density: (**a**) fiber content 1%, fiber length 24 mm; (**b**) fiber content 2%, fiber length 24 mm; (**c**) fiber content 1%, fiber length 48 mm; (**d**) fiber content 2%, fiber length 48 mm. Figure 20: Reinforcement depth-ultimate bearing capacity relationship corresponding to fiber type in tests with Dr = 50% relative density: (**a**) fiber content 1%, fiber length 24 mm; (**b**) fiber content 2%, fiber length 24 mm; (**c**) fiber content 1%, fiber length 48 mm; (**d**) fiber content 2%, fiber length 48 mm. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c} \hline \hline  & & \multicolumn{3}{c}{**Glass**} & \multicolumn{3}{c}{**Macromesh**} & \multicolumn{3}{c}{**Basalt**} & \multicolumn{3}{c}{**Glass +**} & \multicolumn{3}{c}{**Glass +**} & \multicolumn{3}{c}{**Macromesh+**} & \multicolumn{3}{c}{**Glass + Basalt +**} \\  & & & **30\%** & **50\%** & **30\%** & **50\%** & **30\%** & **50\%** & **30\%** & **50\%** & **30\%** & **50\%** & **30\%** & **50\%** & **30\%** & **50\%** \\ \hline \multirow{4}{*}{24 mm} & B & 1.7 & 1.3 & 2.1 & 2.4 & 2.2 & 2.2 & 2.0 & 2.0 & 2.1 & 1.9 & 2.2 & 2.3 & 2.2 & 2.4 \\  & 1\% & 2B & 2.5 & 2.9 & 4.2 & 4.4 & 4.6 & 3.8 & 3.1 & 3.8 & 3.3 & 3.6 & 4.0 & 4.4 & 3.7 & 3.9 \\ \cline{2-15}  & 3B & 3.9 & 3.6 & 5.4 & 5.2 & 6.0 & 4.9 & 4.6 & 4.6 & 5.2 & 4.4 & 5.8 & 5.0 & 5.5 & 4.9 \\ \cline{2-15}  & \multirow{2}{*}{2\%} & B & 2.5 & 1.7 & 3.2 & 3.2 & 2.9 & 3.1 & 2.9 & 2.7 & 2.7 & 2.5 & 3.0 & 3.1 & 2.9 & 2.7 \\  & 2\% & 2B & 4.1 & 3.5 & 6.5 & 6.4 & 5.6 & 5.1 & 5.6 & 4.8 & 5.2 & 4.9 & 5.8 & 6.2 & 5.4 & 5.5 \\ \cline{2-15}  & 3B & 5.3 & 3.9 & 8.4 & 6.3 & 7.5 & 5.8 & 6.4 & 5.6 & 5.9 & 5.4 & 9.0 & 6.1 & 8.3 & 5.9 \\ \hline \multirow{4}{*}{48 mm} & B & 2.0 & 1.8 & 2.8 & 2.6 & & & 2.5 & 2.4 & & & & & & \\  & 2B & 3.5 & 3.4 & 5.4 & 6.1 & & & 4.2 & 5.0 & & & & & & \\ \cline{2-15}  & 3B & 5.2 & 3.8 & 7.2 & 6.8 & & & 6.5 & 6.0 & & & & & & & \\ \cline{2-15}  & \multirow{2}{*}{2\%} & B & 3.2 & 1.9 & 4.8 & 4.0 & & & 3.9 & 3.6 & & & & & & \\ \cline{2-15}  & & 2B & 4.8 & 4.8 & 8.1 & 7.8 & & & 6.7 & 7.2 & & & & & & \\ \cline{2-15}  & 3B & 6.7 & 5.5 & 10.4 & 8.5 & & & 8.5 & 7.3 & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: BCR values obtained as a result of tests. A thorough review of the literature revealed that the use of fibers in geotechnical engineering is applicable in six fields, including pavement layers (road construction), retaining walls, railway embankments, protection of slopes, earthquake, and soil-foundation engineering. According to an existing study, the Bradshaw Field Training Area in Australia's Northern Territory stabilized aprons, taxiways, and a helipad using Portland cement and PP fibers. According to some researchers, the use of fibers in conjunction with geogrids can make it easier and more affordable to build tall vertical walls for railway embankments in low-lying residential areas. Additionally, because they can accept the irregular shape of failed slopes, soil mixtures containing randomly distributed fibers can be employed as patches in the localized repair of slope failures. The fiber reinforcement can eliminate the necessity for an anchorage that is present with planar reinforcement and also lessens gully erosion in the reinforcement of soil veneer, such as landfill covers [46].