Wind tunnel test method to study out-of-service tower crane behaviour in storm winds

An experimental method used to study the behaviour of tower cranes in strong winds exposed to the disturbed shear flow induced by the surrounding built environment is proposed. Wind tunnel tests on a tower crane model are described, the tower crane is considered as a rigid body slender structure equipped with a single degree of freedom part: the crane mobile jib allowing rotation with respect to the vertical axis. Geometrical and mechanical properties are simulated in order to reproduce realistic rotating part behaviour. Instantaneous base overturning moments and rotating part positions are measured in a boundary layer wind tunnel able to simulate the turbulent wind characteristics. Improvements of the design of the crane in order to reduce the crane overturning moments, alleviate undesirable jib rotations and associated failure risks are investigated.