## 5 Conclusions  
This study used a small number of explosives and a small-sized ammunition storage magazine specimen to conduct experiments on explosions inside an ammunition storage magazine to measure the  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Longitudinal Blast with a Retaining Wall** & **Longitudinal Blast without a Retaining Wall** & **Error** \\ **(kPa)** & **(kPa)** & **(\%)** \\ \hline
113.20 & 178.56 & \(-\)36.60 \\ \hline
**Transverse Blast with a Retaining Wall** & **Transverse Blast without a Retaining Wall** & **Error** \\ **(kPa)** & **(kPa)** & **(\%)** \\ \hline
79.38 & 73.66 & 7.77 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Experimental result of using a retaining wall for blast attenuation (explosionat 1\(\times\) the portal diameter inside the ammunition storage magazine).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Item** & **Portal Section** & **1\(d\)** & **3\(d\)** & **5\(d\)** \\ \hline Blast value from the numerical simulation (kPa) & 995.00 & 1040.00 & 153.00 & 61.30 \\ Blast value from the experiment (kPa) & 1864.59 & 1019.77 & 151.21 & 67.50 \\ Relative error (\%) & \(-\)46.64 & 1.98 & 1.18 & \(-\)9.19 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Numerical simulation results for blast outside the ammunition storage magazine.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Longitudinal Blast with a Retaining Wall** & **Longitudinal Blast without a Retaining Wall** & **Error** \\
**(kPa)** & **(kPa)** & **(\%)** \\ \hline
124.03 & 213.29 & \(-\)41.85 \\ \hline
**Transverse Blast with a Retaining Wall** & **Transverse Blast without a Retaining Wall** & **Error** \\
**(kPa)** & **(kPa)** & **(\%)** \\ \hline
143.75 & 119.61 & 20.18 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Experimental results of the effect of a retaining wall on the explosion blast inside the ammunition storage magazine.  
peak overpressure. The experimental results and numerical simulations were validated and compared to build a blast prediction model for near-field explosions in ammunition storage magazines to provide an alternative evaluation for protective design evaluations. The optimal power equation was proposed through regression analysis and was applicable to 1\(\times\) to 653\(\times\) the portal diameter outside the ammunition storage magazine. Additionally, under the effect of a retaining wall on the blast of an explosion inside the ammunition storage magazine, the ammunition storage magazine's longitudinal overpressure was reduced by 37-42%, and the transverse blast was increased by 8-20%. Regarding the numerical simulations, the external overpressure within 1\(\times\) to 5\(\times\) the portal diameter range outside the ammunition storage magazine could be predicted effectively. However, the numerical simulation error was still noticeable for the range of less than 1\(\times\) the portal diameter; as such, further mesh refinement is required to minimize the discrepancy. The proposed approach could serve as an efficient evaluation tool for protective facilities.  
Conceptualization, C.-W.H.; data curation, C.-W.H. and Y.-K.T.; formal analysis, C.-W.H. and P.-W.W.; investigation, C.-W.H., Y.-K.T., T.-A.C., and P.-W.W.; methodology, C.-W.H., Y.-K.T., and T.-A.C.; supervision, C.-W.H. and P.-W.W.; writing--original draft, C.-W.H.; writing--review and editing, Y.-K.T. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The authors declare no conflict of interest.