EFFECT OF AN ADJACENT WALL ON THE OVERTURNING OF A SLIDING-ROCKING BLOCK SUBJECTED TO PULSE EXCITATION

A rigid block placing next to a rigid boundary can be found in many applications of non-structural components in buildings, a typical example is a bookcase and partition wall system. Understanding the dynamics of such a system can help stakeholders better quantify the seismic risk and associated economic losses during an earthquake event. To this end, this paper first describes the governing equations of motion for different response modes of the block, which includes pure sliding, pure rocking and combined sliding-rocking motion. Subsequently, a novel approach based on classical principle of impulse and momentum is developed to handle the rigid block impacting the adjacent wall. The accuracy of the developed model is verified by comparing time-history response with a general-purpose rigid body model in which contact and impact are modeled using a viscoelastic force model. Since the developed model has significant improvement in terms of computational efficiency, it is used for further investigation in this study. The effects of the adjacent wall on the overturning of the rigid block are explored with analytical antisymmetric Ricker pulses. The influence of different parameters is evaluated by comparing the shapes of overturning spectra of the unobstructed and obstructed blocks. It is found that the existence of the adjacent wall significantly complicates the trends of toppling of the block. Generally, decreasing the friction coefficient of the ground, decreasing the clear wall distance and coefficient of restitution of the wall can enhance the stability of the block.