Characteristics and Improved Zoning Methods of Wind Load on Ring-Truss Cable Dome Structures under Downbursts

Abstract Downbursts can generate intense winds near the ground, posing a serious threat to large-span structures. This paper explores the wind load behavior of cable dome structures subjected to downburst events. The study employed wind tunnel pressure tests, in which an impinging jet apparatus was used to simulate downburst wind fields. Field data and theoretical models were compared during the study, and the accuracy of the simulated wind field was verified. Based on this, the wind pressure coefficients and wind force coefficients of cable dome structure were further investigated, particularly their variations at different radial distances and wall heights. To address the discontinuity issue in wind pressure zoning, an improved spatially constrained k -means algorithm is proposed. This algorithm integrates wind pressure coefficients with the spatial coordinates of measurement points, enabling accurate zoning of large-span cable dome structures under downburst action. The results show that the radial distance of downbursts significantly affects the distribution of wind pressure coefficients and three-directional wind force coefficients of the cable dome structure. On the other hand, the wall height has a considerable impact on the wind pressure coefficient distribution, while its effect on the three-directional wind force coefficients is limited.