Civil and Environmental Engineering


Date of this Version



Farooghi-Mehr, S.M. and Wittich, C.E. (2022). Effects of Friction on the Dynamic Behavior of Flexible Rocking Bodies. Proceedings of the 12th National Conference on Earthquake Engineering, Earthquake Engineering Research Institute, Salt Lake City, UT.


Flexible rocking bodies are freestanding structures that are free to deform and rock, potentially overturning, when subject to ground excitation. Prior research on the seismic behavior of this type of structure typically assumed sufficient friction at the ground surface to avoid sliding motion. However, experimental observations showed that this assumption was often violated and structures demonstrated non-negligible sliding during their responses. The overarching goal of this study is to evaluate the impact of sliding on the overturning response of flexible rocking bodies. To this end, a two-dimensional analytical model was developed in a Lagrangian formulation, which is presented in this paper. This model was subjected to one-cycle sine pulses of varying amplitude and frequency for several levels of base friction to quantify the impact of sliding on overturning. In general, the results highlight that sliding behavior reduces the overturning demand, however motion-to-motion variability was observed.