## 4 Blast Analysis Results
### Pylon  
Table 9 presents the damage type, rebar stress, and transverse displacement of the pylon under the different blast load scenarios. The damage range of the pylon column was found to increase with the blast load, and the uppermost crossbeam of the pylon was also considerably damaged by the continuous compression. In Scenarios A and B, the concrete element was not eroded, though damage was observed. In Scenario C, partial spalling of the pylon column occurred near the blast load application point and on the underside of the pylon crossbeam. In Scenario D, concrete failure occurred in the portion of the pylon column level with the explosion; at that location the rebar was exposed. The rebar stress was examined based on a yield strength (f\({}_{\text{y}}\)) of 400 MPa, and the rebars in which the stress exceeded the yield strength are marked in red. In Scenarios A and B, very few rebars yielded at the position of the largest blast load. In Scenario C, numerous rebars began to yield and the damage range was increased. The rebars were fractured in Scenario D. It is believed that the rebar in the uppermost crossbeam of the pylon received a relatively small impact from the blast load; however,  
Figure 14: Effective stress contours of cables: (**a**) Cable no. 37, (**b**) Cable no. 53, and (**c**) Cable no. 68 (fringe level unit: GPa). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Blast Scenario** & **Blast Position** & **Maximum Displacement** & **Maximum Stress** \\ \hline Scenario A & & 74.65 mm & 946 MPa \\ Scenario B & Shoulder/ & 133.81 mm & 1395 MPa \\ Scenario C & Cable no. 37 & 216.94 mm & 1663 MPa \\ Scenario D & & 289.89 mm & 1707 MPa \\ \hline Scenario A & & 111.33 mm & 1380 MPa \\ Scenario B & Shoulder/ & 199.62 mm & 1656 MPa \\ Scenario C & Cable no. 53 & 321.73 mm & 1730 MPa \\ Scenario D & & 428.15 mm & 1814 MPa \\ \hline Scenario A & & 74.94 mm & 1311 MPa \\ Scenario B & Shoulder/ & 134.96 mm & 1641 MPa \\ Scenario C & Cable no. 68 & 220.02 mm & 1703 MPa \\ Scenario D & & 294.46 mm & 1760 MPa \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Summary of blast analysis results for the cables. it yielded owing to the continuous compression of the pylon. The maximum transverse displacements of the pylon are as follows: in Scenario A, local displacements of 9.2 and 18.7 mm occurred at the top of the pylon and at the height of the deck surface, respectively; in Scenarios B and C, local displacements of 19.1 and 59.1 mm at the pylon top and 32.8 and 78.6 mm at the height of the deck surface were observed, respectively; and in Scenario D, displacements of 636.6 and 649.7 mm occurred at the pylon top and the height of the deck surface, respectively, along with a partial fracture of the pylon. Thus, the blast affected the local behavior of the pylon in Scenarios A-C; however, in Scenario D, it affected the overall behavior of the pylon and was even predicted to result in its collapse. Figures 15-17 show the damage contours, axial stress contours, and displacement contours caused by the blast load. The measurement range of the axial stress contours was set to 0-400 MPa considering the yield strength of the rebar, and the measurement range of the displacement contours was set separately, considering the displacement for each scenario. The resulting output time was 1 s, at which point the analysis was terminated. Figure 16: Axial stress contours of the pylon rebars: (**a**) Scenario A, (**b**) Scenario B, (**c**) Scenario C, and (**d**) Scenario D (fringe level unit: GPa).