Response of cantilever grandstands to crowd loads. Part 2: load estimation Available to Purchase

This paper considers the crowd loads encountered on cantilever grandstands and estimates these loads from response measurements. It considers two forms of loading: rhythmic loading which is usually encountered at pop concerts and non-rhythmic loading, usually encountered at football matches. The responses of several grandstands were monitored during pop concerts and the songs that produced the peak responses were identified. For two cantilever tiers at one stadium, the peak responses to four songs were considered. The measurements were processed to determine the accelerations corresponding to the first four Fourier coefficients (FCs) of the rhythmic load. These accelerations were used to determine the FCs of the load. The load model was then used for calculations on two other grandstands. The results were compared with measurements and a reasonable correlation obtained. For non-rhythmic loading the peak responses measured on three grandstands during seven football matches were considered. To represent a crowd jumping to its feet in response to a goal, a simple load model based on the instantaneous removal of the weight of the crowd was considered. Although the calculated displacements were reasonable, the peak accelerations were significantly underestimated on two grandstands.