Cause Analysis And Control Scheme Of Abnormal Vibration In A High-rise Building

The sudden and continuous abnormal vibration of a super high-rise concrete-filled steel tube structure building without earthquake and obvious extreme meteorological conditions caused obvious vibration sensation in the building,which led to the analysis and discussion of the cause of abnormal vibration of the building by relevant experts and scholars.This paper aims to analyze the cause of abnormal vibration of the super high-rise structure by combining theoretical analysis,numerical analysis and conceptual design.Finally,a number of vibration control schemes are designed and their vibration control effects are analyzed.Firstly,based on the conceptual design,it is considered that the building has a small damping ratio and the dynamic characteristics of natural vibration frequency are the preconditions leading to the abnormal vibration of the building.Considering the external conditions such as the building’s environment,it is judged that the subway vibration,wind-induced vibration of the main structure and vortex-induced vibration of the antenna structure are the main factors causing the abnormal vibration of the building.Then the influence law and degree of these three factors on building vibration are analyzed respectively.The analysis process can be summarized as establishing the analysis model,simulating the vibration load,inputting the vibration load,extracting the vibration response of the model,analyzing the law and degree of vibration response,etc.Combined with the definition of the degree of influence of different types of vibration on human body feeling in the relevant vibration comfort specifications,it is considered that the vibration response law and degree of building structure induced by VIV of antenna structure are most consistent with the actual situation,and the mechanism of abnormal vibration of building can be judged as follows:Under certain wind field conditions,the third order VIV effect occurs in the roof antenna structure,and the vibration is transmitted down through the structure column and causes the resonance effect of the higher order vibration mode of the main structure of the building.Finally,based on the VIV of the antenna,different vibration control strategies are adopted to reconstruct the antenna,including adjusting frequency,increasing mass and increasing damping,etc.Three vibration control schemes are proposed to analyze the suppression effect of each scheme on the VIV of the antenna and the resonance effect of the main structure.The results show that the VIV effect of the antenna structure can be effectively suppressed by the three vibration control schemes,and the vibration response of the main structure can be obviously controlled.