## 4 Analysis of Korea Container Crane
### Selection of Ground Motions  
The crane is located on a reclamation area which used to be a soft ground area with a standard penetration test (SPT) N-value smaller than 10 (based on data of over 50 boreholes obtained prior to reclamation). To consider the effects of local soil conditions serving for the seismic analysis of the crane, ten more boreholes have been made within 30 m depth at the site. Several laboratory and field-testing methods were used, such as SPT; water ground measurement; cone penetration test (CPT); and density logging, especially the S-PS logging test for measuring P-wave and S-wave velocity. A summary of the soil properties at a specific harbor is shown in Table 3. The soil investigation report at the crane location showed that the mean shear wave velocity for the top 30 m of ground throughout the five boreholes of the S-PS logging test ranged from 247 m/s to 447 m/s. Based on the crane's site, seismic zone I is identified, at which a seismic zone factor S = 0.22 g is assigned for a maximum considered earthquake (MCE) with a 2400-year mean recurrence interval. The design acceleration response spectrum is then developed corresponding to site coefficients F\({}_{\text{a}}\) and F\({}_{\text{v}}\). From the soil investigation results, the average shear wave velocity of the ground within 30 m depth is approximately 338 m/s, thus the soil type S\({}_{\text{D}}\) is selected according to KDS [13]. Correspondingly, the spectral acceleration (S\({}_{\text{a}}\)) at the structure's fundamental mode (T = 1.35 s) is approximately 0.21 g. This shaking intensity is considered to be the upper-bound value. The lower bound is selected as a seismic zone factor S = 0.06 g (equivalent to a 100-year return period), whereas the median shaking intensity is chosen corresponding to a 500-year return period with S = 0.11 g. These elastic response spectra are provided by KDS, as shown in Figure 5. The selected S\({}_{\text{a}}\) at the fundamental periods of the structure are estimated at 0.07 g, 0.13 g, and 0.21 g for the lower bound, median, and upper bounds of ground motions, respectively. Figure 5: Soil type S\({}_{\text{D-1}}\) elastic response spectra (5% damping) of KDS for 100, 500, and 2400 years return. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Soil Type**} & \multicolumn{2}{c}{**Unit Weight, \(\gamma\)**} & \multicolumn{2}{c}{**Shear Wave**} & \multicolumn{2}{c}{**Shear**} & \multirow{2}{*}{**Poisson’s**} \\  & \multicolumn{2}{c}{**(kN/m\({}^{3}\))**} & \multicolumn{2}{c}{**Velocity, \(\mathbf{v_{s}}\)**} & & **Modulus, G** \\  & & **(kN/m\({}^{3}\))** & **(m/s)** & **(MPa)** & **Ratio, \(\mathbf{v}\)** \\ \hline Buried layer & Riprap & 19 & 345 & 2.47 \(\times\) 10\({}^{2}\) & - \\  & Sand & 18 & 323 & 2.06 \(\times\) 10\({}^{2}\) & 0.35 \\  & Pebble & 18 & 295 & 1.67 \(\times\) 10\({}^{2}\) & 0.35 \\ Sediment & Clay & 17 & 203 & 3.34 \(\times\) 10\({}^{6}\) & 0.33 \\  & Pebble & 19 & 379 & 2.31 \(\times\) 10\({}^{7}\) & 0.33 \\ Weathered soil & & 19 & 542 & 5.84 \(\times\) 10\({}^{7}\) & 0.33 \\ Weathered rock & & 20 & 471 & 1.71 \(\times\) 10\({}^{8}\) & 0.30 \\ Soft rock & & 23 & 1265 & 6.69 \(\times\) 10\({}^{8}\) & 0.28 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Soil investigation at the crane location. A set of 20 natural time-history ground motions worldwide is used in this study [23; 25]. They are summarized in Table 4. These ground motions have different magnitudes, durations, PGAs, and fault distances, and were recorded from 1940 to 1999. The response spectra of these unscaled ground motions are scaled corresponding to the three earthquake target IM levels to generate 60 different time-history ground motions. Then, all input earthquakes are applied to a 3D FE model using nonlinear time-history analysis. Then, the best estimate, and lower and upper bound (10 th and 90 th percentiles) profiles can be chosen by sorting the EDPs, as previously mentioned in Section 3.2.