Determination of Period of RC Buildings by the Ambient Vibration Method

Abstract

Determining the dynamic properties of structures is important for understanding their seismic behaviour. Ambient vibration signal measurement is one of the approaches used to determine the period of structures. Advantages of this method include the possibility of taking real-time records and presenting nondestructive and rapid solutions. In this study, natural vibration periods are calculated by taking ambient vibration signal records from 40 buildings. The height of the building, infill wall effect, presence of seismic retrofit, and presence of damage are taken into consideration, and their effects on natural vibration periods are investigated. Moreover, the results are compared with the analytical methods to reveal the differences. A significant correlation between the period and height of the building is observed. It is seen that the natural vibration periods of the buildings decrease by 7% to 30% (15% on average) due to infill wall contribution. However, the efficiency of infill walls decreases as the building height increases. Another significant result is that adding shear walls substantially decreases the vibration period values by 23% to 33% with respect to the shear wall ratio. When the analytical estimates and measured building period results are compared, it is seen that analytical models have closer period estimates before infill walls are implemented. The limited data in scope of the study suggest that significant differences may present in the analytical and measured periods of the buildings due to infill wall contributions.

Estimating vibration period of reinforced concrete moment resisting frame buildings

“…Model Location ASCE/SEI 7-16 [1] 𝑇 𝑓 = 0.0466 𝐻 0.9 USA Eurocode 8 [2] 𝑇 𝑓 = 0.075 𝐻 3/4 Europe FEMA 450 [3] 𝑇 𝑓 = 0.0524 𝐻 0.9 USA Hong and Hwang [6] 𝑇 𝑓 = 0.0294 𝐻 0.804 Taiwan Michel et al [43] 𝑇 𝑓 = 0.013 𝐻 France Chiauzzi et al [7] 𝑇 𝑓 = 0.037 𝐻 0.76 Canada Guler et al [8] 𝑇 𝑓 = 0.026 𝐻 0.9 Turkey Velani and Ramancharla [11] 𝑇 𝑓 = 0.009 𝐻 1.1 India Inel et al [9] 𝑇 𝑓 = 0.0343 𝐻…”

“…On the other hand, several models were developed based on the recorded ambient vibrations of the buildings in different regions in the world. Guler et al [8], Inel et al [9] and Kaplan et al [10] considered buildings in Turkey. Velani and Ramancharla [11] and Velani and Kumar [12] considered buildings in India.…”

Developing a Feature Extraction of Existing Structures Using an Ambient Vibration Test

“…In theory, each peak is proportional to the natural mode of the structure. The main limitation of this technique is the inability to distinguish between the frequencies of modes that are very close in terms of quantity [11].…”