Research On Super High-rise Typhoon Effect Based On Actual Measurement

As China’s urban land reserves have decreased,urban construction land has become more and more tense,prompting the society to look at the development of the building and gradually look to the super high-rise.Especially in cities with relatively developed economies in the coastal areas,super high-rises not only ease the tension of urban land and transportation,but also represent the image and symbols of their own cities through super high-rise buildings.However,due to the high height,light weight and high flexibility of super high-rise buildings,the wind sensitivity under the typhoon will be strengthened.The low natural frequency and damping ratio of the modal parameters of super high-rise buildings will cause the natural frequency of the structure to be closer to the main frequency of the wind load applied by the typhoon,resulting in a larger wind-induced structural response.Therefore,based on the structural health monitoring system,this paper studies the wind load and structural dynamic response of Shenzhen Ping an International Financial Center under the influence of typhoon.The main research contents are as follows:Taking the first high in South China-Shenzhen Ping An International Financial Center(599 meters)as the engineering background of the typhoon research.Through the monitoring content of Shenzhen Ping An Financial Center Structural Health Monitoring System which is an important way of this paper,the composition framework of this set of constructing health monitoring system is introduced in detail.The function of each sub-module is analyzed in detail,and the main contents and current completion of the monitoring of the system are explained carefully.The wind environment,curtain wall wind pressure and acceleration response during the transit of the typhoon "hato" and "Pakhar" were monitored on site through the completed monitoring system and equipment.The wind environment characteristics of Shenzhen Ping An Financial Center during the typhoon transit period were analyzed in detail.During the typhoon "hato"the characteristics of ambient wind were analyzed,and the changes of average wind speed,gust wind speed,relative pressure and temperature under the action of non-through typhoon wind field were studied.by the data of the near-Earth meteorological station provided by the Shenzhen Meteorological Bureau.The law of changes in air pressure and temperature.Through comparative analysis,it is found that the wind speed of the near-Earth weather station deployed in the city is smaller than the wind speed of the near-Earth weather station installed at the seaside;the site located in the city center is smaller than the site located in the open area.During the typhoon "Pakhar",the characteristics of the ambient wind were analyzed through the three-way anemometer at the top of the tower,and the changes of horizontal wind speed,wind direction and vertical wind speed at the top of the tower were studied.During the transit period of typhoon,the wind load characteristics of the structUral curtain wall of Shenzhen Ping’an Financial Center were analyzed.The time domain variation of wind pressure load at each measuring point on the front and coner of the structural curtain wall of some floors of Shenzhen Ping’an Financial Center,the non-Gaussian characteristics of each measuring point,the pulsating wind pressure power spectrum of specific flow direction and Wind pressure correlation of the windward side of each curtain wall are analyzed.The study found that the extreme negative pressure on the front side of the curtain wall of Shenzhen Ping’an Financial Center appeared on the side,which is greater than the extreme positive pressure on the windward side.The extreme negative pressure at the corner of the curtain wall is greater than the extreme negative pressure on the front of the curtain wall,So the failure point of the curtain wall will appear first in the comer.The non-Gaussian wind load of the curtain wall will be more obvious with the increase of negative pressure,but there is no same change law for positive pressure.After analyzing the wind pressure power spectrum of the specific inflow direction,the identification of the vortex shedding frequency of the building is determined.The Strehal number of the building is obtained through analysis and calculation,which is consistent with the wind tunnel test results.It is understood from the correlation analysis that the low-frequency and large-scale vortex will lead to strong coherence of different fagades of the whole building,while the vortex with smaller high frequency only has a large local influence.When the coherent phase of the peak of the side coherence is about 180 degrees,the alternating appearance of vortex shedding on the side is illustrated.The dynamic response of the Wind-induced structure of Shenzhen Ping’an International Financial Center during the typhoon transit period was analyzed.The variation law of the wind-induced acceleration response of the structure in the time domain is analyzed.It is found that the magnitude of the acceleration response increases with the increase of the layer height;By analyzing the power spectral density,the natural vibration frequency in the structural modal parameters is identified and compared with the results of the finite element analysis.The first few modes of the structural mode are compared.It is observed that the first-order bending mode plays a dominant role in the first few modes,and the first-order bending mode is an order of magnitude bigger than the first-order torsional mode;Comparing the two measured vibration modes with the finite element results,it is found that the comparative analysis of the first and second order bending and the first order torsion is in good agreement,and the degree of correlation between the measured modal results and the finite element results using the modal guarantee criteria and the standardized modal difference is the same as the comparison conclusion;The self-vibration frequency and damping ratio in the modal parameters of the structure are identified by using the combination of EMD technology and RDT technology Subsequent research explored the degree of correlation between the two and the response amplitude,and learned that the correlation after normalization agrees well with the first-order bending modes.