Dimensional analysis of dynamic interaction between adjacent SDOF buildings to forward directivity and fling step pulses

Abstract A series of parametric analyses are conducted to investigate the combined effects of impact and structure-soil-structure interaction on a pair of closely spaced buildings in response to near-fault forward-directivity and fling-step pulses. The soil-buildings system is simplified into a discrete spring-mass-dashpot model, and ground motions are simulated using simple mathematical pulses, which enables a wide range of parameters defining the physical system and the input pulses to be covered. Displacement spectra with and without impacting are obtained using a dimensional analysis for comparison purposes. It is shown that near-fault pulses are highly possible to result in high colliding potentials of flexible-base buildings, especially those on very soft soils when subjected to fling-step pulses. It is concluded that impact amplifies displacement demands of smaller-sized buildings when fundamental frequencies of the buildings are relatively lower than pulse frequencies. On the other hand, impact amplifies displacement demands of larger-sized buildings while reducing those of smaller-sized buildings when fundamental frequencies of the buildings are relatively higher than pulse frequencies. Special attentions of collision issues should be paid to buildings that are expected to suffer moderate damage.