Study On The Wind Resistance Design Of Super High-rise Building Based On The Mesoscale WRF Simulation And The Lidar Field Measurement

The characteristics of atmospheric boundary layer wind field and its effect on building structures are fundamental problems in structural wind engineering research.Wind load is often the controlling load in the design of super high-rise buildings,which affects the structural safety and the comfort of human habitation.Accurate description of wind field characteristics is an important prerequisite for wind resistance research of super high-rise buildings.The characteristics of the real atmospheric boundary layer wind field are very complex,which is not only affected by the mesoscale atmospheric circulation at the scale of 1000 meters,but also affected by the disturbance of the near-surface topography and buildings.In this paper,by means of numerical simulation,wind tunnel test and field measurement,the wind field characteristics of the atmospheric boundary layer and the wind resistance of super high-rise buildings are studied.The main content is divided into the following aspects:(1)Comparative study on mesoscale WRF simulation and measurement of boundary layer wind field in typical geomorphologic environment.Firstly,based on the Weather Research and Forecasting(WRF)model in the field of next generation meteorology,the Four-dimensional Data Assimilation(FDDA)module was set up,and an optimized combination of physical parameters was using to simulate the wind field in the area with Shenzhen Meteorological Tower site as the center.The simulated wind field characteristics of this area such as instantaneous wind speed,10-minute average wind speed and direction,average wind speed profile,etc.,are compared with the measured data of two types of anemometers of Shenzhen Meteorological Tower and the data of two lidars(Wind3D 6000 Lidar and Wind Mast PBL Lidar).The results showed that: 1)During the study period,based on the measured data of the gradient tower ultrasonic anemometer and the measured data of the wind profile lidar,the maximum root mean square errors of the 10-minute average wind speed of the boundary layer wind field at the tower site simulated by WRF model are 2.67 m / s and 1.56 m / s.The accuracy and applicability of the mesoscale model established in this study to simulate the good-state wind field are verified.2)The comparison and analysis of the observed data between the two lidars show that the root mean square errors of the 10-minute average wind speed and wind direction angle are 0.38 m / s and 12.02 °,and the correlation coefficients are more than 0.98 and 0.99.It shows that the wind field observation data of the two lidars have good consistency and high correlation.The measured wind field characteristics and wind profile accuracy are higher than those of the gradient tower anemometer,which verifies the accuracy and reliability of the lidar measurement of boundary layer wind field.3)The average wind profile index fitted by ultrasonic anemometer during the observation period is 0.38,and the measured result of wind profile lidar is 0.24.The gradient wind height is higher than the standard definition of class B geomorphology of 350 m,indicating that the geomorphological roughness index α at the meteorological tower site is greater than the standard definition of class B wind field of0.15.This indicates that the characteristics of the real atmospheric boundary layer wind field under natural conditions are more complex than the theoretical wind field model defined in the code,and more attention should be paid to the wind field itself in the study of wind resistance of structures.(2)The wind resistance design of super high-rise buildings is studied by WRF numerical simulation,lidar measurement and wind tunnel test.A super high-rise building(350m)in Foshan was selected as the research object.Firstly,WRF mesoscale simulation and lidar field measurement of the atmospheric boundary layer wind field of the building site were carried out.Then,the wind load and wind-induced response of the super high-rise building were analyzed by using the wind tunnel test of the rigid model.The results showed as follows: 1)Based on the established WRF mesoscale model,the wind field characteristics of the actual atmospheric boundary layer at the project location in the study period can be well reconstructed;2)The wind profile fitted with the measured lidar data shows that the average wind velocity profile index αmeasured at the project location during this period is greater than the landform C profile index judged according to the code,and exceeds the landform D index by 0.30;3)After modifying the local landform D wind field of the project site according to the measured results,the calculated base wind load and the peak acceleration of the top floor of human dwelling decreased to different degrees in accordance with the results of landform C in the specification when the corresponding incoming wind was downward.Therefore,combined with the measured results of the lidar,it can be inferred that the design wind load obtained by the calculation and analysis based on the value of landform C wind field defined in the specification of this project is biased towards safety.