## 2 Experimental Setup  
### Simulations of Boundary Layer Wind Fields  
The wind tunnel tests were conducted for the same CAARC model in the open-circuit wind tunnel at Chongqing University (CQU) and the closed-circuit wind tunnel at Harbin Institute of Technology (HIT), respectively. The test section of the CQU wind tunnel (turbulence intensity \(<\) 0.5%) has dimensions of 2.4 m \(\times\) 1.8 m (width \(\times\) height), with a wind speed range of 0.5-40 m/s. The test section of the HIT wind tunnel (turbulence intensity \(<\) 0.5%) has dimensions of 4.0 m \(\times\) 3.0 m (width \(\times\) height), with a wind speed range of 3-50 m/s. Spires and cube roughness elements [23] were used for simulating boundary layer wind fields in Category C, according to the load code for the design of building structures in China [24], with the scale ratio of 1:300. Category C refers to urban areas with dense building clusters. The power-law index of the wind speed profile for C-Category is 0.22. The model scale ratio was determined based on the sizes of the two wind tunnels, ensuring that the blockage ratio in both wind tunnels remains below 5%. The flow velocities were measured using a TFI Cobra probe made in Tallangatta, Australia at CQU, and the sampling frequency was 500 Hz and the measurement duration was 60 s, while HIT utilized a hot-wire anemometer made in Skovlunde, Denmark as the wind speed measurement instrument, with a data acquisition system of multi-channel MiniCTA, and the sampling frequency was set at 1000 Hz with a sampling time of 80 s. Typically, to capture accurate fluctuating wind speed values, the sampling frequency for wind speed measurements is generally no less than 100 Hz. In this study, both wind tunnel laboratories meet the required sampling frequency. The equipment used in both wind tunnel laboratories is commonly employed in wind tunnel testing, and the measured results exhibit good consistency. Therefore, the subsequent comparison can be considered valid. Figure 1a shows the measured along-wind mean wind speed U and turbulence intensities \(\mathrm{I_{u}}\) at various heights of the test section, as well as the corresponding vertical profiles of Category C guided by the code. The height Z and U are normalized by the model height H and corresponding mean wind speed \(\mathrm{U_{H}}\), respectively. The scale ratio for wind field simulation is 1:300. The power-law index \(\alpha\) was calculated by fitting the measured data to Equation (1). The power-law indices of the regression lines for the wind tunnel were 0.228 and 0.219, corresponding to CQU and HIT, respectively. Compared with the target value of 0.22, this indicates that the simulated wind fields align well with the C-Category terrain curves specified in the code. Figure 1b shows the power spectrum of the along-wind component at H, \(\mathrm{k_{1}}=\mathrm{f}\mathrm{I_{u}^{x}}/\mathrm{U}\) demonstrating the reduced frequency and \(f\) is the frequency. Evidently, the measured spectra are concordant with the von Karman spectrum. \[\mathrm{U}=\mathrm{U_{H}}\bigg{(}\frac{\mathrm{Z}}{\mathrm{Z_{H}}}\bigg{)}^{ \alpha} \tag{1}\]  
where \(\mathrm{Z_{H}}\) is the reference height, which is set as the model height H. \(\mathrm{U_{H}}\) is the wind speed at \(\mathrm{Z_{H}}\), U is the wind speed at \(\mathrm{Z}\), and \(\mathrm{Z}\) is the height above the ground. The calculation of the turbulence integral scale (\(\mathrm{I_{x}^{u}}\)) is based on the covariance function [25; 26], as shown in Equation (2). Table 1 presents the main parameters of the longitudinal turbulence flow field at the height of 2/3 H. D represents the width of the windward face. Due to the larger dimensions of the test section at HIT, the measured turbulent integral scale is correspondingly larger, which is about 1.2 times that of CQU.