Measurement And Visualization Of Wind-induced Response Of Tall Buildings

With the application of lightweight and high strength materials,high-rise buildings have the characteristics of lightweight,high flexibility and low damping.Under the action of typhoon,high-rise buildings are prone to produce large wind-induced vibration,which affects the structural safety and living comfort.In the case of typhoon landing,the wind-induced response data of high-rise buildings can be obtained through field measurement,which can effectively understand the operation status of building structures.Among them,the wind-induced displacement response is an important index to reflect the vibration state of the structure under wind load,but due to the limitation of instruments and equipment,the dynamic displacement response of high-rise building structure can not be measured directly.At the same time,the expression of measured data is often in the form of two-dimensional chart,which is not easy for researchers to understand the measured results.Based on the measurement of the wind-induced response of a high-rise building in Wenzhou and the visualization method of the measured results when typhoon "Maria" was logged in,the specific research contents are summarized as follows:First of all,the site,building,system and "Maria" of high-rise building typhoon field measurement are introduced.The acceleration responses of several key floors of the building and the wind field data on the top of the building are obtained through the actual measurement.At the same time,the method and theory of modal identification are introduced.By processing the measured data,the dynamic characteristic parameters of the high-rise building are successfully identified.The frequencies and modes of the translational modes in two directions are similar,which indicates that the stiffness of the measured structure in two directions is relatively close.Secondly,the calculation method of wind-induced displacement response is introduced.The calculation of wind-induced displacement is divided into pulsating displacement calculation and static displacement calculation.For the calculation of fluctuating displacement,this paper uses the round test method to judge whether the structure is in the stage of steady vibration.The acceleration data in the stationary vibration stage is selected to identify the extreme point in the acceleration time history,and the modified point is taken as the integral starting point of the acceleration,and then the trend term is removed to obtain the velocity time history.Then,the extreme points in the velocity time history are identified,and the modified points are taken as the starting points of velocity integration,and the fluctuating displacement time history is obtained by removing the trend term.For the calculation of the average displacement,the measured building structure is simplified as a five mass bending shear layer model by using the equivalent principle.The data of wind speed and direction are converted into the average wind load,and the average wind load is applied to the measured building simplified model to calculate the static displacement of the structure.The wind-induced displacement response of the acceleration measurement floor is obtained by superposition of the two.Then,the linear interpolation method is used to obtain the wind-induced displacement response of non acceleration measurement floor.The problem that the wind-induced displacement response of high-rise building structure can not be measured directly is solved.The results show that the root mean value and peak value of the wind-induced displacement response increase with the increase of height,and the values of the two directions are close.Thirdly,it introduces the software of Revit,the process of creating the model of Revit and the transformation of BIM model file format.At the same time,this paper introduces the webgl,Java EE and other computer technologies involved in the development of the visual display system of measured data,and uses three.js technology to analyze the transformed BIM model data,and successfully reconstructs the measured building BIM model on the web side.The structural connection and material of the reconstructed BIM model and the three-dimensional model displayed in Revit have no change,but they are slightly different in illumination and texture map.Finally,using BIM,webgl and Java EE technology,a visual display system of wind-induced displacement response based on BIM model is developed.Using the advantage of three-dimensional visualization of BIM Technology,the linkage between the building and the measured data is realized.The time history of wind-induced displacement response calculated from the measured data is successfully displayed on the building BIM model,which makes the measured results easy to understand.