## 4 Results
### Parametric Analysis of the Failure Load  
The parameters utilized in the parametric analysis are detailed in Section 2 and depicted in Figure 4. Comparisons with the prestressed model are conducted using distinct graphs. The first parameter is the height of the dap \(h_{d}\). The comparison of the results is presented in Figures 10 and 11 through the \(h/H\) ratio (ratio of the reduced height section to full height of the beam). The prestressed reinforcement results are provided in Figure 10. A ratio of 1.0 indicates that there is no dap and that the tendons cross the forming cracks, leading to a spike in the failure load, as seen in the DIANA FEA curve. With a ratio of 0.83 (and lower), the tendons do not cross the critical cracks, and thus, they do not impact bearing capacity. In terms of accuracy, when there is a dap, the [PERSON] et al. method is the most closely aligned with the results of the non-prestressed numerical model. The EC2 STM and PCI calculations demonstrate the behavior of methods which evaluate the failure load with higher reserves for safety reasons. The EC2 method 6.2 overestimated the capacity at all points, except in cases where there was no dap. Figure 11: Comparison of varying h/H ratios on the failure load when the reinforcement is prestressed. Figure 10: Comparison of varying h/H ratios on the failure load. The impact of prestressed tendons on the bearing capacity is shown in Figure 11, comparing the results of prestressed and non-prestressed reinforcement. With an \(h/H\) ratio of 1.0, the prestressed tendons compressed the critical cracks, leading to a 5.52% increase in the failure load, rising from 661.54 kN to 698.08 kN. However, when the prestressed tendons pressed on the wall of the dap, there was no increase in the bearing capacity. On the contrary, the tensile stresses induced at the re-entrant corner of the dap with a \(h/H\) ratio of 0.17 resulted in a 4.27% decrease in the failure load. The comparison between the numerical model and the analytical methods revealed that the EC2 6.2 method overestimated the bearing capacity in the presence of a dap. The dap height can also be analyzed through the \(a/d\) ratio (shear span to effective height of the nib ratio) shown in Figures 12 and 13. The results reflect typical, often described behavior: as the \(a/d\) ratio increases, the bearing capacity decreases [1; 25; 26; 27]. Unexpected behavior can be seen when analyzing Figure 13. The bearing capacity of the structure decreased due to prestressing the most when \(a/d\) reached its highest value; however, according to the behavior described in the literature, when the \(a/d\) ratio increases, the failure usually occurs due to bending moments rather than shear [28]. Another analyzed parameter was the support placement point in the dapped end, which is expressed by the \(l_{s}/l_{d}\) ratio. The results are shown in Figures 14 and 15. The  
Figure 12: Comparison of varying \(a/d\) ratios on the failure load. Figure 13: Comparison of varying \(a/d\) ratios on the failure load when the reinforcement is prestressed. trend of decreasing bearing capacity due to the increase in the \(l_{s}/l_{d}\) ratio can be compared to the previously described change in the \(a/d\) ratio. As the value of \(l_{s}/l_{d}\) increased, so did the \(a/d\) ratio, and, as a result, the failure load decreased, as is typical for such an element. Analyzing the results, the behavior of the non-prestressed numerical model most closely matches the results of the [PERSON] et al. method. The calculated bearing capacity was slightly lower than the numerical model for all points, except for the 0.40 ratio. The EC2 6.2 section overestimated the bearing capacity when the support was in the range between the middle of the dap and the end of the nib. From Figure 14, the bearing capacity of the non-prestressed numerical model differed by 42.94% depending on where the supporting point was added to the dap, which most closely matches the change of the beam bearing capacity according to the [PERSON] et al. method.