## 3 Determination of the Wind Load  
### Wind Tunnel Tests  
To obtain the aerodynamic force data for quayside container cranes, wind tunnel tests were conducted on rigid models. A 657-65M container crane with a weight of 1380 t was applied as the prototype as it is the most widely used type among ports and terminals. The crane has a rated lifting capacity of 65 t and a lifting height of 65 m. The geometric characteristics of the container crane model and coordinate system are displayed in Figure 2. Both boom-down and boom-up positions were considered in the tests. Rigid models (Figure 3) with a geometric scale of 1:150 were fabricated for the wind tunnel tests with a maximum blockage ratio of 2.7%. There are two boom positions for the crane. The boom is horizontal as a boom-down state when lifting and loading containers. The non-working resting elevation angle of 80\({}^{\circ}\) was set in the boom-up state when resting or suffering from windstorms or other extreme weather. Aiming to model the actual arrangement pattern in ports, three models with the same size for both boom-up and boom-down positions were provided. The measured models were made of steel with welded joints so that the models were rigid enough to avoid aeroelastic effects and fluid-structure coupling. Figure 1: Process of calculating the wind-induced response. Figure 2: Test models: (**a**) boom-down state; and (**b**) boom-up state. The balance was fixed under the center of the turn table, sharing the same position with the measured model. Figure 3 shows the layout when measuring the wind load of the 3# crane with \(\alpha=0^{\circ}\). Thus, three layouts were included in one group-arrangement case (e.g., case No. 3 in Table 1), so that all three models could be measured. The wind tunnel tests were conducted in the boundary layer wind tunnel at Tianjin Research Institute for Water Transport Engineering (TIWTE). It is a straight-flow wind tunnel with a rectangular test section and an open area in the inlet and outlet of the tunnel. The dimensions of the wind tunnel are 4.4 m \(\times\) 2.5 m \(\times\) 15 m (width \(\times\) height \(\times\) length). In the tests, a coastal atmospheric boundary layer condition (terrain type A in Chinese code [11]) is simulated. The simulated mean wind speed profile was set to follow the power-law profile with an exponent of \(\alpha=0.12\). The measured mean wind velocity, turbulence intensity profiles, and power spectrum density of fluctuating winds are shown in Figure 4, which are thought to have a good agreement with the code. The boom-down model height, \(H=550\) mm, was set as the reference height. Regardless of the Reynolds number when the wind speed is beyond \(5\times 10^{5}\), the mean aerodynamic-force coefficients acting on the crane model have nearly constant values [16]. Within this range of Reynolds number, the wind velocity is set as 10 m/s with a scale of 1:3. The wind velocity is measured in the center of the test location using a TFI Cobra Probe with a sampling rate of 1250 Hz. The reduced power spectrum of the measured wind velocity at the reference height followed the von Karman-type spectrum with an integral length scale of \(H\) at the reference height. To investigate the interference among the cranes, the three models with the same state were laid in a line for both states. The nondimensional spacing \(S/H\) is defined with center spacing \(S\) and reference height \(H\). It is set as 0.484, 0.848, and 1.211, which corresponds to 40, 70, and 100 m of the center spacing in the terminals. The top view of the group-arranged \begin{table}
\begin{tabular}{c c c c} \hline
**No.** & **Model Status** & **Arrangement** & **Spacing (m)** \\ \hline
1 & Boom-down & isolated & - \\
2 & Boom-up & isolated & - \\
3 & Boom-down & group-arranged & 40 \\
4 & Boom-down & group-arranged & 70 \\
5 & Boom-down & group-arranged & 100 \\
6 & Boom-up & group-arranged & 40 \\
7 & Boom-up & group-arranged & 70 \\
8 & Boom-up & group-arranged & 100 \\ \hline \end{tabular}
\end{table}