| The long span flat roof, a typical large span roof, is widely used in architectures. But The structure is strong sensitivity to the wind loads. Currently the provisions of wind vibration coefficientβz in the existing GB-50009 are only for the high-rise structure and high-rise structure in the main, considering only the first vibration mode of the structure rather than long span flat roof.Studies of seismic response,wind-induced response and equivalent static wind load are carried out on—Single-span plane truss,Double-span plane truss,Truss String Structure and Space Truss—the four commonly used the long span flat roofs for wind loads,earthquake and structural parameters within commonly used engineering and the applied wind-resistant method of the long span flat roofs is proposed. The main results in this paper have been achieved as follows:(1) Parametric analysis and comparisons between seismic response and wind-induced response are carried out on the four common long span flat roofs. And then reasonable comparison tables of seismic response and wind-induced response are set for preliminary design of the structure to evaluate the controlled load of structure.(2) Based three-component method, parameter study is done on wind-induced response for the four common long span flat roofs above. Further, changes of resonant response/background response are detailed. Finally, the practically specific criteria of the flat roof structure are summarized.(3) On the basis of wind-induced response, the multiple equivalent objectives are divided into mean wind pressure coefficient and the equivalent static wind load fluctuating pressure coefficient. Parameter study is done on Cf (equivalent to the wind load factors multiply the high coefficient). The fitting formulas of Cf with a certain probability are given and expressed as a function of frequency conversion. Finally, the practical expressions of vibration coefficient for multiple equivalent objectives are given according to Cf for structure of the wind-resistant design. The standard value of wind loads can be accessed directly by expressions of Cf during structural design. |
