# Experimental and Numerical Studies on Ground Shock Generated by Large Equivalent Surface Explosions
## 6 Conclusions  
In this study, the ground shock generated by the 1 t TNT surface explosion was successfully measured. The applicability of the empirical equations provided by the UFC 3-340-01 was discussed, and a numerical study to analyze the effects of ground shocks on buildings around an explosion was conducted. The conclusions of this study are as follows:  
1. The intensity of ground shock decreased with the increase in distance from the blast site, and the accelerations in the X and Y direction were both higher than that in the Z direction.
2. The seismic wave velocity \(c\) and attenuation coefficient of the soil \(n\) at the experimental site were found to be \(c=457\) m/s and \(n=2.55\). The applicability of the empirical equations provided by the UFC 3-340-01 was validated for our experiment by the determined parameters \(c\) and \(n\).
3. The attenuation behavior of the maximum particle vibration velocities around the epicenter of 1 t and 10 t TNT explosion were obtained, and the minimum safe distance was computed for a variety of structures.  
The research results will be applied to the construction and planning scheme of the site selection for hazardous chemicals in a port in the near future. The safety distance of surrounding buildings will be evaluated, and a reasonable safety distance will be applied.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**To-Be-Protected Structure** & **Minimum Distance for Vibration Safety (m)** \\ \hline Cave dwellings, adobe houses, and rubble houses & 23.7–29.6 \\ Ordinary civilian buildings & 17.5–19.0 \\ Industrial and commercial buildings & 14.1–15.2 \\ Ordinary historical buildings and sites & 38.3–47.8 \\ Central control room equipment in operational & 29.6–33.1 \\ hydropower stations and power stations & 8.7–10.4 \\ Hydraulic tunnels & 7.4–8.7 \\ Mine roadways & 6.5–7.0 \\ Permanent rocky high slopes & 8.7–10.4 \\ Age: Initial setting-3 days & 17.5–19.0 \\ Age: 3–7 days & 12.2–14.1 \\ Age: 7–28 days & 9.6–10.4 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Minimum distance for the vibration safety of a 1 t TNT blast.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**To-Be-Protected Structure** & **Minimum Distance for Vibration Safety (m)** \\ \hline Cave dwellings, adobe houses, and rubble houses & 51.1–63.8 \\ Ordinary civilian buildings & 37.8–40.9 \\ Industrial and commercial buildings & 30.3–32.7 \\ Ordinary historical buildings and sites & 82.4–102.9 \\ Central control room equipment in operational & 63.8–71.2 \\ hydropower stations and power stations & 18.8–22.4 \\ Traffic tunnels & 16.6–18.8 \\ Mine roadways & 13.9–15 \\ Permanent rocky high slopes & 18.8–22.4 \\ Age: Initial setting-3 days & 37.8–40.9 \\ Age: 3–7 days & 26.2–30.3 \\ Age: 7–28 days & 20.7–22.4 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Minimum distance for vibration safety of a 10 t TNT blast.  
review & editing. R.X.: Investigation, Resources. M.C.: Data curation, Resources. D.C.: Formal analysis, Investigation, Software. Q.F.: Conceptualization, Funding acquisition, Project administration. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the National Natural Science Foundation of China (No. 51978166).  
Not applicable.  
Data Availability Statement: Data sharing is not applicable to this article.  
Thanks to all the authors for their comments and suggestions on the manuscript.  
The authors declare no conflict of interest.