# Inter-Story Drift Ratio Detection of High-Rise Buildings Based on Ambient Noise Recordings
## 2 Data Acquisition  
This project was conducted examining the Zhonghe Building at Tongji University in Shanghai. Twenty-four SMARTSOLO IGU-16 HR 3C three-component seismometers were deployed from the 1 st floor to the 21 st floor of the Zhonghe Building, as well as at two points in the parking lot and lawn for comparison. The data were collected for 19 consecutive days, from 20 November 2021 to 9 December 2021.  
The Zhonghe Building is a 22-story building, including 1 underground floor and 21 aboveground floors. The total height of the building is 102 m, and the height of the aboveground part is 98 m. The aboveground part of the building is composed of seven modules, each of which consists of three floors. Between every two modules, there are 2 m high equipment interlayers as transition layers for the structure. Most of the floors of the Zhonghe Building are 4 m high and consist of approximately nine 16.2 m \(\times\) 16.2 m rectangular units, with only the B1 level having a height of 6 m.  
The stressed areas of each floor are roughly L-shaped blocks, and the stressed areas within the same module are roughly the same. The seven modules spiral up clockwise from bottom to top; the upper module is rotated 90\({}^{\circ}\) clockwise from the lower module and is stacked on one side of the L-shaped structure of the lower module.  
In general, the structure of the Zhonghe Building can be considered as a frame structure with a viscous damping support system [18]. According to [PERSON] [19], when a frame structure is subjected to lateral loads, the relationship between the top drift and the shape function of the distributed load can be presented as follows:  
\[\begin{cases}\delta_{xe}(x)=\frac{V_{b}}{H}\Big{[}x-\frac{x^{(k+2)}}{(k+2)H^{(k+1) }}\Big{]}\\ Q(x)=\frac{V_{b}}{H}(k+1)\big{(}\frac{x}{H}\big{)}^{k}\end{cases} \tag{1}\]  
where \(x\) is the distance from the computed point to the ground, \(\delta_{xe}(x)\) is the top drift, \(Q(x)\) is the shape function of the distributed load, \(V_{b}\) is a summation of all lateral forces applied at each story level, \(H\) is the total height, and \(k\) is an exponent related to the structural period.  
[PERSON]'s formulas reflect that the function of top drift has a degree that is two units higher than the function of distributed loads. Similar characteristics of the deformation of an idealized frame structure under a horizontal force can be inferred as follows: (1) the deformation is small near the ground; (2) the deformation grows rapidly in the middle floors; and (3) the deformation increases slowly at high-rise floors and peaks at the highest point. According to [PERSON] [20], a viscous damper is better suited for controlling the torsional angular velocity and has no significant effect in controlling inter-story drift. Therefore, the deformation of the Zhonghe Building under a wind load should have similar characteristics to [PERSON]'s description. However, the Zhonghe Building is a modern building with a complex structure. Therefore, its deformation characteristics may not be completely consistent with the description above.  
The structure's diagram and instrument positions are shown in Figure 1.  
Figure 1 shows the structure of the Zhonghe Building and the instrument positions marked with black dots. The elevation and plan in Figure 1 are arranged in the southwest  
Figure 1: Sketch of the structure of the Zhonghe Building.  
direction. Seven modules, each consisting of three floors, jointly compose the aboveground part of the building. The stressed areas in the structure are L-shaped blocks divided into two parts: the transverse stress areas highlighted in blue, and the longitudinal stress areas highlighted in red. There are two fixed elevator and stair areas in the southeast and northwest areas. Additionally, the instruments were set in the southeast stair area of each floor for recording and in the parking lot and lawn for comparison.