Research On Wind-induced Interference Effects Of Long-span Dome-roof

Because of its beautiful appearance and good structural efficiency,the long-span dome structure is widely used to construct large public buildings such as gymnasiums and convention centers.The wind load on the doom-roof surface is an important factor considered in structural design.In recent years,as China undertakes more and more major international events,more and more long-span dome structures are built in the prosperous urban area,and there are often dense buildings around them.These interference buildings will have a severe impact on the wind field environment around the long-span dome structure,and the characteristics such as the velocity and direction of the incoming wind will be significantly changed,resulting in the "interference effect" on the wind load of long-span dome roof.However,there are no provisions on the wind-induced interference effect of long-span dome in the current design code,and there is no reference basis for this problem in practical engineering.Therefore,in order to better guide the wind resistance design of long-span dome structure,this paper uses Computational Fluid Dynamics(CFD)method to conduct a comprehensive and in-depth study on the law and mechanism of the interference effect of a single building and building group on the wind load of long-span dome roof.Firstly,based on the Reynolds average method in CFD,RNG k-ε turbulence model is used to simulate non-interference building conditions and interference building conditions.The simulation results are compared with the wind tunnel test results to verify the accuracy of the numerical simulation method.In order to more accurately analyze the changes of wind load at different positions on the roof,the long-span dome roof is divided into circular areas,and the wind load data processed by the circular partition method is compared with the data obtained by the traditional strip partition method,which proves the superiority of the by circular partition method.Next,the wind-induced interference effect of a cube building on the long-span dome roof is numerically simulated.Considering the influencing factors such as the size,location and wind direction of the interference building,the unifactor rotational experiment and orthogonal experimental design method are used to study the interference effect on the wind pressure of each area and overall roof.The results show that the "passage effect" is the main reason for the "amplification effect" of wind pressure,and the height of the interference building plays a leading role in the strength of the " passage effect ".The region between the center of the dome-roof and the interference building experiences the highest amplification,while the side area on the roof close to the rear of the interference building is safer.Finally,single interference building is extended to the building group to explore the interference effect of different surrounding forms and building area density on the wind pressure.The results demonstrate that the upstream and downstream buildings decrease the wind pressures,while the buildings on the side of the inflow amplify the wind pressures.When there are interference buildings on the sides of the incoming flow,the wind pressure on the roof increases significantly,and the interference effect is the most severe in the central area of the roof and the area adjacent to the interference buildings.Therefore,the long-span dome structure should be avoided as far as possible in the middle of the two rows of buildings.The interference effect is directly proportional to the building area density,so too dense buildings on the sides of the long-span dome structure shall be avoided as far as possible.