# Damage Assessment of Shear Wall Structures in an Earthquake-Blast Disaster Chain
## 3 Numerical Simulation
### Earthquake-Blast Disaster Chain  
The three recorded seismic events, namely, the Hector Mine, San Fernando, and Imperial Valley events, were applied to the example shear wall structure. The PGA of each record was normalized to 0.1 g, which is compatible with the Chinese design response spectrum at a 5% damping ratio [34]. Figure 5 illustrates the three selected earthquake ground motions. Further details of the three used seismic events are listed in Table 5.  
\begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline \multicolumn{1}{c}{**Air (”MAT\_NULL\&”EOS\_LINEAR\_POLYNOMIAL)**} & & & & & & \\ \hline Initial density & Initial energy \(E_{0}\) & Pressure cutoff & Dynamic viscosity coefficient & \(C_{0}\), \(C_{1}\), \(C_{2}\), \(C_{3}\), \(C_{6}\) & \(C_{4}\), \(C_{5}\) \\
1.29 kg/m\({}^{3}\) & \(2.5\times 10^{5}\) J/m\({}^{3}\) & 0 & 0 & 0 & 0 & 0.4 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Parameters of air.  
\begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline \multicolumn{1}{c}{**Concrete (”MAT\_JOHNSON\_HOLMQUIST\_CONCRETE \& “MAT\_ADD\_EROSION)**} & & & & & & \\ \hline Density & G & A & B & C & N & FC & T & EPS0 \\
2440 kg/m\({}^{3}\) & 14.86 GPa & 0.79 & 1.6 & 0.007 & 0.61 & 0.048 GPa & 4 & 1 s\({}^{-1}\) \\ EFMIN & SRNAX & PC & UC & PL & UL & D1 & D2 & K1 \\
0.01 & 7 & 0.016 GPa & 0.001 & 0.8 GPa & 0.1 & 0.04 & 1 & \\ K1 & K2 & K3 & Failure strain & & & & & \\
85 GPa & \(-\)171 GPa & 208 GPa & 0.01 & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Parameters of the constitutive concrete model.  
\begin{table}
\begin{tabular}{l l l l l l l l l} \hline \hline \multicolumn{1}{c}{**TNT (”MAT\_HIGH\_EXPLOSIVE\_BURN \& “EOS\_JWL)**} & & & & & & \\ \hline Initial density & Detonation velocity D & Burst pressure \(P_{CJ}\) & A & B & \(R_{1}\) & \(R_{2}\) & \(\omega\) & \(E_{0}\) \\
1630 kg/m\({}^{3}\) & 6930 m/s & 21 GPa & 373.8 GPa & 3.747 GPa & 4.15 & 0.9 & 0.35 & \(6\times 10^{9}\) J/m\({}^{3}\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Parameters of TNT.  
The simulation parameters adopted for the blast loads in this paper were as follows:  
1. The concentration of methane in the first and sixth story was assumed to be the worst possible (i.e., 9.5% [19]), and the mass equivalent of TNT can be obtained by Equation (2), that is, 150 kg.
2. Consider that there would be many pipelines buried underground, but also that the story drift ratio of the sixth floor is the largest after the earthquake. The pipelines are prone to damage, and thus the explosion takes place in one of four locations: the corner room on the first floor, the middle room on the first floor, the corner room on the sixth floor, or the middle room on the sixth floor, as shown in Figure 6.
3. The explosion occurs in the center of the appropriate mentioned room.  
Table 6 lists 15 cases of earthquake-blast disaster chains. Cases 1-3 represent the scenarios without explosions. Cases 4-6, 7-9, 10-12, and 13-15 describe the scenarios with an earthquake combined with a blast in the corner room on the first floor, the middle room on the first floor, the corner room on the sixth floor, and the middle room on the sixth floor, respectively. In all cases, the structural responses, in terms of roof displacement, story drift ratio, and explosion overpressure, are systematically investigated and represented in the following section.  
Figure 5: (a) Spectra of three scaled time history records based on design spectra; and (b) comparison of the designed response spectra and the mean response spectra.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Record Number** & **Events** & **Date** & **Station Name** & **Duration (s)** \\ \hline A\_1 & Hector Mine & 16 October 1999 &
\begin{tabular}{c} San Bernardino-N \\ Verdemont Sch \\ \end{tabular} & 37.80 \\ A\_2 & San Fernando & 9 February 1971 & Maricopa Array \#2 & 29.48 \\ A\_3 & Imperial Valley & 15 October 1979 & Niland Fire Station & 32.00 \\ \hline \end{tabular}
\end{table}
Table 5: Earthquake events.