Dynamic Characteristics Test And Numerical Simulation Analysis Of Super High Rise Frame Core Tube Structure

With the development of population, politics and economy, the high-rise structure is developing rapidly in recent years. Super high-rise structure has its unique advantages, but there are also risks, so safety and seismic performance of high-rise structure receives much concern.On the engineering background of a super high-rise frame core structure,this paper aims at the dynamic characteristic testing on site and finite element numerical simulation analysis. Through comparing measured results with theoretical results of dynamic properties, the dynamic performance of the structure is objectively and scientifically evaluated on the basis of relevant codes.The main contents and conclusions of this paper are as follows:(1)The dynamic property of the structure was detected by pulsation method on site and the dynamic parameters were obtained, including horizontal transversal, horizontal longitudinal and torsional frequency, formine, damping ratio and stiffness. In the testing on site, testing environment, monitoring point arrangement and sensor placement were studied, and announcements and details of dynamic testing were summarized.(2)The simplified calculating method of equal lateral stiffness for steel reinforced concrete column in super high-rise frame core structure was studied,simplified the steel reinforced concrete column into ordinary reinforced concrete column then applied it into the whole building modal. In this project, the ratio of simplified cross sectional area and the designed cross sectional area of steel reinforced concrete column was 1.044, which provides theoretical reference andtechnical basis for finite element analysis of similar engineering projects.(3)Using ANSYS finite element software to establish the finite element modal of the super high-rise structure, theoretical value of dynamic parameters were obtained through computational analysis and the calculation results were analyzed, which provides theoretical reference for evaluating the dynamic performance of structure. Meanwhile, the finite element modeling method and experience of super high-rise frame core structure were summarized, which provides technical basis for finite element analysis of similar engineering projects.( 4) Through contrastive analysis of measured data on site and finite element calculation results, conclusions of dynamic characteristics of the whole structure can be drawn: as for the horizontal transversal, horizontal longitudinal and torsional frequency, the measured first five natural vibration frequency was slightly larger than the calculated value. For example, the ratio of the first torsional natural cycle Tt and the first horizontal natural cycle T1 was 0.73 while the calculated value by ANSYS was 0.66. The measured vibration modes were in line with the calculated modes. So the overall dynamic performance of the structure met the requirements of relevant codes. The construction quality is good and has no obvious damage and defects.