Refined Analysis Of Wind-induced Vibration Response Of Super-tall Structures Of Different Shapes

A large number of actual measurements at this stage show that the dynamic characteristics of high-rise structures are quite different from the theoretical values at the design stage,and the structurally calculated wind vibration acceleration in the proposed stage is often greater than the measured wind vibration acceleration after operation.The reason may be that the calculated wind The calculation model used in the vibration response is different from the actual state of the building during operation and cannot reflect the real vibration of the building.In response to this problem,this article first summarizes and compares the China,the America and the Japan load code,the Australian/New Zealand code and the International Standards Association ISO standard.Five types of codes are used to calculate the wind load and vibration acceleration of a square and a rectangular super high-rise structure,and compared with the rigid model wind tunnel test results.Then the finite element software is used to analyze the wind acceleration of the structure,and the similarities and differences between the wind acceleration and the wind tunnel test results under different loading modes of super high-rise structures with different degrees of refinement are studied.The good calculation model provides a feasible method for the analysis of wind-induced vibration response and comfort assessment of the complex high-rise structures in the urban building complex.The main work and results of this article are as follows:1.Based on the above five codes,study the three-way wind load,top floor acceleration and calculation parameters of two super-tall structures of different shapes.It can be seen that the Chinese load code is about basic wind pressure,ground roughness category,wind load carrier type coefficient,wind pressure height The definition of the coefficient of variation and the calculation formula are relatively reasonable,but the peak factor value of the Chinese code is smaller than the peak factor calculated by the other four codes;the Australian/New Zealand code and the ISO standard are used to calculate the downwind load of the super high-rise structure.The standard calculated value is obviously small,and the standard calculated value of China codes and the Japan is in the middle.Moreover,the Chinese codes and the Japanese codes calculate the windward acceleration of the two types of super-tall buildings in the downwind direction.The calculation results of the United States and Australia/New Zealand codes are much higher than those of the Chinese codes and the Japanese codes,indicating that the Chinese code is suitable for the windward loads of different tall supertall buildings The calculation results of its wind acceleration are relatively reasonable and reliable,but the prediction results of the cross-wind wind load and its acceleration are still not perfect.The formula for calculating the equivalent wind load in the cross-wind direction in China is in urgent need of improvement.2.Study the wind tunnel test of a rigid model of a square and a rectangular super high-rise structure,and compare and analyze the obtained internal force and vertex acceleration of the structure with the calculated values of the aforementioned specifications.It can be seen that the horizontal bending moment values calculated according to the Chinese codes,the Japanese codes,the Australian codes and the ISO codes are all larger than the wind tunnel test values,which shows that the calculation of the wind and cross wind loads of super high-rise structures according to the national wind codes is biased towards safety;For square super high-rise structures,the cross-wind wind vibration response even exceeds the downwind direction and becomes the main factor affecting the structural wind-induced vibration response;but for rectangular super-tall structures,if the windward surface is much larger than the crosswind surface,then the crosswind acceleration and the downwind acceleration The difference is small;and the acceleration of wind-induced vibration response of super high-rise buildings according to Chinese code is relatively small.It is recommended to evaluate wind-induced vibration acceleration based on wind tunnel tests.3.Using ETABS finite element software to analyze the wind vibration time history of a square and a rectangular super high-rise structure,simplify the floor slab into rigid or quasi-rigid partitions with different degrees of refinement,and compare the wind vibration of the structure under centroid loading or distributed loading The response is different,and the similarities and differences with the wind tunnel experimental data are analyzed to obtain the best calculation model for calculating the wind-induced vibration response of super-tall structures of different shapes.The results show that: compared with the results of the combined mode of rigid partitions and centroid loading commonly used in typical high-rise structures,for square super concave high-rise structures,the floor slab is simplified into multiple rigid partitions matching the actual cross-sectional shape of the structure,and distributed The loading is the most reasonable;and for the rectangular super high-rise structure,the floor slab is simplified to a quasi-rigid partition,and the acceleration of the top layer calculated by using the centroid loading is more in line with the actual situation than using the distributed loading calculation.