Study On Wind-load And Shape Coefficient Of Urban Buildings Under Typical Wind Field In Xinjiang

Wind disasters often bring great losses to cities.A strong wind will cause the destruction of buildings,exterior decoration materials and even the destruction of exterior walls.With the rapid development of urbanization,complex,long-span and high-rise building structures emerge one after another,and urban building group become more and more dense.The problems of building wind resistance and urban wind environment become more and more obvious.As an important means to study the wind field around buildings,numerical simulation can simulate a variety of working conditions and provide a large number of reliable data.In this paper,Computational Fluid Dynamics（CFD）method is adopted to study the distribution of wind load on the wall of single building and wind-induced disturbance of randomly clustered buildings.The specific work contents and conclusions are as follows:（1）Based on the satellite map and meteorological data,the architectural forms and local wind environment characteristics of three regions in Xinjiang are analyzed,and the H-shaped buildings,Stunt-shaped buildings,T-shaped buildings,special-shaped Xinjiang Grand Theater and building group are selected as the research objects.（2）Combined with the local wind environment,the wind pressure distribution law on the surface of H-shaped buildings,Stunt-shaped buildings and T-shaped buildings under different length-width ratio,depth-width ratio and wind direction angle parameters was systematically studied,and the wind load shape coefficient of building surface under different wind direction angle was calculated according to the code.The results show that :（1）With the increase of the width of the rear side of the H-shaped building,the wind load on the side wall and the leeward side of the building increases,and with the increase of the width of the front side of the H-shaped building,the wind load on the whole building decreases;the higher the height of H-shaped building,the greater the wind load on the building surface;under the wind direction angle of 0°,the H-shaped building is subjected to the maximum wind load,with the maximum wind-load shape coefficient of 1.8 and the minimum of-1.3.（2）The increase of the length of the Stunt-shaped buildings for the purpose of changing the corner spacing is beneficial to reduce the wind load on the Stunt-shaped building surface;the higher the height of the Stunt-shaped buildings,the greater the wind load on the building surface;under the wind direction Angle of 0°,the Stunt-shaped buildings are subjected to the maximum wind load,with the maximum wind-load shape coefficient of 3.2 and the minimum of-1.4.（3）For T-shaped buildings,the wind load on the side wall and the leeward side increases with the increase of the building length,while the increase of the building width is not conducive to reducing the wind load on the building wall;the reduction of the height of T-shaped building is beneficial to reduce the wind load on the building wall;T-shaped buildings are subjected to the maximum wind load at the wind direction angle of 135°,with the maximum wind-load shape coefficient of 3.2 and the minimum of-3.2.（3）According to the characteristics of the development of the flow field around the buildings,the measures of corner treatment and partial opening are adopted to improve the wind suction on the side wall and the wind pressure on the windward side of the three kinds of single buildings.The results show that :（1）The maximum positive pressure of the windward side and the maximum negative pressure of the leeward side can be reduced by 34% and 24% by 10% rounded corners of the H-shaped building;the wind pressure coefficient on the whole wall of the H-shaped building can be reduced by half when the front and back sides and front sides of the H-shaped building are opened.（2）The maximum positive pressure on the windward side is reduced by 77%,the maximum negative pressure on the side wall is reduced by 25%,and the maximum negative pressure on the leeward side is reduced by 16% by 10% corner cut of the Stunt-shaped building;the maximum positive pressure on the windward side is reduced by 44% and the maximum negative pressure on the leeward side is reduced by 11%when both the upper and lower sides of the building are opened.（3）The wind pressure on the T-shaped building surface can not be reduced by 10% rounded corners and corner cut treatment;the maximum negative pressure on the leeward side is reduced by 71%when the lower part of the T-shaped building is opened.（4）The influence of different wind direction angles on the wind pressure distribution on the surface of hemispherical large span building Xinjiang Grand Theater under the wind environment in Urumqi area is studied.The results show that the Grand Theater bears the most unfavorable wind-load under the wind direction angle of 180°.Taking the most adverse wind direction angle as an example,the wind-load shape coefficient on the surface of Xinjiang Grand Theater was calculated.The maximum wind-load shape coefficient was 0.6,distributed on the windward side of the building,and the minimum wind-load shape coefficient was-1.5,distributed on the roof of the Grand Theater.The wind-load shape coefficient of the Grand Theater at the most unfavorable wind angle can be used as a reference for wind resistance design of similar hemispherical large-span buildings.（5）Take a building group in Urumqi,Xinjiang as an example to study the wind-induced disturbance of buildings under regional wind environment in Urumqi.The results show that:（1）the upstream buildings affect the wind pressure on the windward and side walls of the downstream buildings,while the downstream buildings may affect the wind pressure on the leeward side of the upstream buildings.（2）The "narrow tube effect" formed by the buildings with a left-right parallel position will increase the local wind speed and affect the wind pressure on the side wall of the building.Based on the study of the surface wind pressure of individual buildings and the wind environment of the building group,the paper puts forward some suggestions to improve the wind environment of the building group from the aspects of building form,building layout and regional environment,and provides some references for the layout of similar building groups in Xinjiang.