A Numerical Study of the Effect of Ground Motions and Gap Distance Due to Seismic Pounding With the Use of Gap Element Between Regular and Irregular Adjacent Structures

Earthquakes with high magnitudes and strong ground motion have a more pronounced impact on structures that are positioned in close proximity to one another, as opposed to those that are more widely spaced. This proximity can lead to structural pounding, resulting in significant damage or even localized failure. The extent of pounding is influenced by both the insufficient separation distance between adjacent structures and the intensity of ground motion. Building codes worldwide stipulate a minimum separation distance to mitigate these effects. This study aims to evaluate the seismic pounding forces between adjacent reinforced concrete structures under varying ground motions, and to assess the influence of separation distance and structural irregularity on pounding behavior. Additionally, the effect of the structural mass on pounding force has also been discussed. Adjacent structures with differing floor levels were considered, and non-linear time history analyses were conducted using finite element-based software. Four real earthquake records with diverse characteristics and magnitudes were used to simulate ground motion effects. The results demonstrate that both Peak Ground Acceleration (PGA) and separation distance significantly affect the magnitude of pounding forces. Specifically, higher PGA values lead to substantial variations in pounding forces across different floors, while increased separation distance reduces the impact of pounding forces between adjacent structures. Moreover, structural irregularity and structural mass also contributes to differentiating the pounding forces.