## 3 Record Selection  
Seven near-fault records from the Pacific Earthquake Engineering Research Center-Next Generation Attenuation (PEER-NGA) [66] were selected in this study. It has been shown in the literature that the vertical earthquake component significantly affects the seismic response of liquid storage tanks, particularly the impulsive response [8, 67, 68]. Therefore, all three earthquake components were considered in the analysis of the three-dimensional liquid storage tank. According to [69], the site-to-source distance boundary between near-fault and far-fault earthquakes is 10 km. Therefore, the distance between the recording site and the rupture plane of all selected earthquakes was less than 10 km. All records used in this study had a moment magnitude greater than 6.5 (\(M_{\text{w}}>6.5\)). ASCE7 classifies records as near-fault if the moment magnitude is greater than 6 and the site-to-source distance is less than 10 km [70]. According to [71], the average PGV of near-fault earthquakes is considerably higher than that of far-fault earthquakes. As a result, the records were selected so that they had a PGV greater than 30 cm/s. Table 4 summarizes these earthquakes.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Parameter** & **L** & **W** & **h\({}_{\text{w}}\)** & **h\({}_{\text{l}}\)** & **tw\({}_{\text{u}}\)** & **tw\({}_{\text{b}}\)** \\ \hline Value (m) & 18.00 & 14.00 & 5.00 & 4.00 & 0.20 & 0.40 \\ \hline \hline \end{tabular}
\end{table}
Table 2: The dimensional properties of the tank and the water.  
Figure 4: Geometrical parameters of the water–tank system.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Material** & \(\rho\) (**Kg/m3**) & **E (GPa)** & \(\
u\) & \(\mu\) \\ \hline Concrete & 2400 & 22.69 & 0.17 & - \\ Water & 1000 & 2.1 & – & 0.001 \\ \hline \hline \end{tabular} where \(\rho\), E, \(\
u\), and \(\mu\) are the density, young modulus, Poisson’s ratio, and viscosity, respectively.  
\end{table}
Table 3: The material properties of the tank and the water.  
Among the earthquakes shown in Table 4. 5 are pulse-like earthquakes (#3, #4, #5, #6, and #7), and the remaining are non-pulse earthquakes (#1 and #2). The pulse period of the pulse-like earthquakes ranges from 3.53 to 6.27. According to [72], when the pulse period approaches the fundamental sloshing period (\(\frac{T_{sloshing}}{T_{P}}\approx 1\)), the sloshing response considerably increases. In selecting the records for this study, the effect of approaching the pulse period to the fundamental sloshing period on the sloshing response of the tank along its length and width was considered.  
The spectral accelerations of the selected records at the tank's first five sloshing modes, along the tank's length and width, differed from one another.  
The major horizontal component of the selected earthquakes, shown in Table 4, was scaled to 0.4 g. Using the same scaling factor used to scale the major horizontal component of the earthquake, the second (minor) horizontal component and the vertical component were also scaled. Table 5 shows the PGA and PGV of the horizontal and vertical components of the selected earthquakes after being scaled.  
The tank was subjected to the earthquakes in such a way that the main horizontal component of the ground motions, the one scaled to 0.4 g, acted once parallel to the longer wall and once parallel to the shorter wall. The minor horizontal component acted perpendicular to the major component in both loading conditions. The vertical earthquake component was also considered in the analysis of the tank.