On the basis of the yearbooks of the Japan Construction Safety and Health Association, wind-induced structural accidents during construction were investigated on the death and serious accidents where more than 3 people were killed or injured. These data were compared with data of overseas wind-induced accidents collected from Engineering News-Record. The wind-induced structural accidents were classified according to the accident types, and their countermeasures for safety were examined. From the investigation, it was found both in Japan and overseas that the collapse accidents during construction have the high rate in the whole construction accidents and about 10% of the serious collapse accidents were due to wind. Furthermore, it was also found that in Japan the ratio of the collapse accidents due to wind had not been changed since 1970, and the countermeasures for the prevention of the collapse accidents were proposed.
Special attention is paid to the phenomenon of which fluctuations due to small scale eddies in the inertial range of fully turbulent flows provide intermittency. In order to investigate this intermittent structure in natural winds, the wavelet transform is applied to the time history of a measured wind velocity fluctuation. Reflecting the intermittency, the result indicates that the probability density functions of the wavelet coefficients at high scale-parameters, which correspond to the statistical characteristics of the small scale fluctuations, deviate from the Gaussian distributions. Taking this intermittency into account, a method using the inverse wavelet transform to generate artificial wind velocity data is suggested. The characteristics of the time histories produced with the proposed method are discussed.
Wind characteristics by the undulated topography is one of the most important items to evaluate wind loads for structures. This paper describes the result of wind tunnel tests of some fundamental escarpment and the area, where some transmission pylons are turned over at the typhoons 9117 and 9119. The models of fundamental escarpment changes its slope angle, height, surface roughness and approaching flow conditions. The obtained data indicates that the surface roughness affects a lot for the mean wind speed distribution, although the gust wind speed does not change. From the wind tunnel test of the actual area, the wind is found to be affected by both speed-ups by ‘escarpment’ and large-scale turbulence due to vortices from the upstream steep hill.