## 2 Outline of the Experimental Procedure
### Data Processing  
The mean wind pressure coefficient \(\overline{C}_{Pi}\) and fluctuating wind pressure coefficient \(\widetilde{C}_{Pi}\) (standard deviation) of measuring point \(i\) can be obtained from the converted wind pressure measured by the scanning valve according to Formulas (1) and (2).  
\[\overline{C}_{Pi}=\frac{\overline{P}_{i}-P_{0}}{0.5\rho U_{H}{}^{2}} \tag{1}\]  
\[\widetilde{C}_{Pi}=\frac{1}{0.5\rho U_{H}{}^{2}}\sqrt{\left\{\sum\left(P_{i}- \overline{P}_{i}\right)^{2}\right\}/\left(N-1\right)} \tag{2}\]  
where \(\overline{P}_{i}\) and \(P_{0}\) are the mean wind pressure and static pressure, respectively; and \(\rho\) and \(U_{H}\) are the air density (\(\rho\) = 1.255 g/cm\({}^{3}\)) and wind velocity (\(U_{H}\) = 12 m/s) during the experiment, respectively.  
The aerodynamic coefficients of the train-bridge system can be approximately obtained by integrating the wind pressure coefficients at each measuring point. The aerodynamic force of the WGB can be obtained by subtracting the aerodynamic force of the bridge  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Wind Barrier Types**} & **Width of WGB Root** & **Angle of Main Deflector Plate** & **Size of the Upper Deflector Angle** \\ \cline{2-4}  & \(B_{1}\) **(mm)** & \(\theta_{1}\) (\({}^{\circ}\)) & \(h_{1}\) **(mm)** \\ \hline
1 & & No barrier & \\
2 & & Vertical wind barrier (30\% ventilation rate) & \\
3 & 300 & 20 & 350 \\
4 & 300 & 10 & 350 \\
5 & 300 & 20 & 500 \\
6 & 350 & 10 & 350 \\
7 & 250 & 10 & 350 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Types of WGB tests.  
from the force measured by the ATI-type scale on the bridge-barrier system. The definition of the aerodynamic coefficients is as follows:  
\[C_{H}=\frac{2F_{H}}{\rho U^{2}H}\approx\sum C_{Pi}L_{i}\cos\alpha_{i}/H \tag{3}\]  
\[C_{V}=\frac{2F_{V}}{\rho U^{2}B}\approx\sum C_{Pi}L_{i}\sin\alpha_{i}/B \tag{4}\]  
\[C_{M}=\frac{2M}{\rho U^{2}B^{2}}\approx\sum\left(C_{Pi}L_{i}\cos\alpha_{i}Y_{i }+C_{Pi}L_{i}\sin\alpha_{i}X_{i}\right)/B^{2} \tag{5}\]  
where \(C_{H}\), \(C_{V}\), and \(C_{M}\) are the lateral force coefficient, lift coefficient, and moment coefficient in the body axis system, respectively; \(F_{H}\), \(F_{V}\), and \(F_{M}\) are the aerodynamic forces measured by the ATI-type scale, respectively; \(L_{i}\) is the integration length represented by measurement point \(i\); \(\alpha\) is the outer normal vector angle of the pressure measuring hole in the model section; \(H\) and \(B\) are the characteristic height and width of the train and bridge, respectively; the torsional moment coefficient of the train-bridge system is calculated with the centroid of the train and bridge as the reference point.  
The original data collected by the Cobra probe includes a matrix of time series sequences of wind velocity in three directions: streamwise direction (\(u\)), bridge transverse direction (\(v\)), and bridge vertical direction (\(w\)). After removing bad data points, the mean wind velocity for each direction is calculated by taking the mean of the valid data points. The vector sum of the three mean wind velocity \(\overline{u}\), \(\overline{v}\), \(\overline{w}\) is used to obtain the overall mean wind velocity \(\overline{V}\). The total turbulence intensity \(I_{total}\) is equal to the ratio of the turbulent pulsation velocity to the mean velocity, \(I_{total}\) is calculated according to Equation (10).  
\[u=\overline{u}+u \tag{6}\]  
\[v=\overline{v}+v \tag{7}\]  
\[w=\overline{w}+w\prime \tag{8}\]  
\[\overline{V}=\sqrt{\overline{u}^{2}+\overline{v}^{2}+\overline{w}^{2}} \tag{9}\]  
\[I_{total}=\sqrt{\frac{1}{3}\left(\overline{u^{\prime 2}}+\overline{v^{\prime 2}}+ \overline{w^{\prime 2}}\right)}/\left|\overline{V}\right| \tag{10}\]