## 4 Experimental Modal Parameters Analysis  
### Comparisons of the Measured Vibration Modes and Those Simulated by Finite Element Method  
As shown in Figure 14, the first-order vibration modes of all measured floors along the torsional direction are basically the same. The second-order vibration modes of the 6 th, 12 th, and 18 th floors along the X and Y axes have an opposite vibration direction with that of the 30 th floor, while the third-order vibration modes of the 6 th, 12 th, and 30 th floors along the X and Y axes have an opposite direction to those of the 18 th and 24 th floors. Besides, along the torsional direction, the vibration directions of the 24 th and 28 th floors were opposite to those of the 8 th, 12 th, and 16 th floors at the second-order frequencies, and the vibration directions of the 8 th, 12 th, 16 th, and 28 th floors were opposite to those of the 20 th and 24 th floors. All these results were all in good agreement with those identified by the measured phase spectrum, which indicated that there were few disturbances when measuring the responses of each floor, thus the inherent attributes of the high-rise building can be also recognized. Meanwhile, modal assurance criteria (MAC) were adopted to check reliability, and its range was 0-1. If the value of MAC was more than 0.7, it meant that there was huge correlation between the two order modes, and that there may exist false modes or unknown branch structures. The verification results of modal correlation along the X axis, Y axis, and torsional direction are shown in Figure 15.  
Figure 14: The measured vibration modes at the first three orders along the X and Y axis and torsional direction: (**a**) the first-order vibration mode along the X axis; (**b**) the second-order vibration mode along X axis; (**c**) the third-order vibration mode along the X axis; (**d**) the first-order vibration mode along the Y axis; (**e**) the second-order vibration mode along the Y axis; (**f**) the third-order vibration mode along the Y axis; (**g**) the first-order vibration mode along the torsional direction; (**h**) the second-order vibration mode along the torsional direction; and (**i**) the third-order vibration mode along the torsional direction. According to Figure 15, MAC of the first three order vibration modes along the X axis, Y axis, and the torsional direction are all less than 0.2, which presents that there are weak correlations between different order modes, and that the first three-order modal vibration modes are reliable. Meanwhile, finite element numerical analysis (FENA) Midas/Gen was also applied to conduct the numerical simulation and Eigenvalue calculations of the high-rise building, and the major structure was simulated for the beam and plate element. The equivalent mass of filler wall, glass curtain wall, and other similar structures was calculated without considering stiffness, and these structures were all loaded linearly on the beam elements. Because the filler wall has windows and doors, a constant load conversion coefficient of 0.75 was adopted to conduct the numerical simulation. The top side of building foundation was regarded as the fixed end, and only the load transfer of foundation and superstructure was considered in the process of numerical simulation regardless of the interrelationship between foundation and superstructure and that between the foundation soil and building within basement range. Figure 16 presents the finite numerical simulation results of the first three-order vibration modes along the X axis, Y axis, and torsional directions. Table 3 shows the comparison of the measured values and those calculated by definite element numerical simulation of the first three-order frequencies, and the comparison results show that the simulation results of the first three-order vibration modes along X axis, Y axis, and torsional direction are in good accordance with those of the measured results, and that the deviations of the simulated modal frequencies are all within 7%.