Rigid Impacts of Three-dimensional Rocking Structures

Abstract Studies of rocking motion aim to explain the remarkable earthquake resistence of rocking structures . State - of - the -art assessment methods are mostly based on planar models , despite ongoing efforts to understand the significance of three - dimensionality . Impacts are essential components of rocking motion . We present experimental measurements of free -rocking blocks , focusing on extreme sensitivity of impacts to geometric imperfections , unpredictability , and the emergence of three - dimensional motion via spontaneous symmetry breaking . These results inspire the development of new impact models of three dimensional facet and edge impacts of polyhedral objects . Our model is a natural generalization of existing planar models based on the seminal work of George W. Housner . Model parameters are estimated empirically for rectangular blocks . Finally , new perspectives in earthquake assessment of rocking structures are discussed .