Seismic Pounding Between Adjacent RC Buildings with Asymmetric Alignment

During earthquakes, adjacent structures may collide with each other due to different dynamic characteristics. When buildings vibrate out-of-phase and the separation gap provided between buildings is not sufficient to accommodate their relative motions, collisions can cause severe damage or even complete collapse of structures, and is known as seismic pounding. In metropolitan cities, due to increased population and land values, buildings have been constructed with inadequate separation distance between them. The seismic oscillations induced in a structure in a block of buildings will be partly restrained in lateral displacements and hence torsional movements are introduced (asymmetric pounding). Two different types of impacts may occur during pounding including floor-to-floor and floor-to-column (inter-storey) collisions. In this paper, the effects of asymmetric (contact asymmetry) pounding on the seismic response of adjacent buildings with symmetric plan and unequal building heights are studied. Time history analysis of adjacent buildings with different pounding cases involving 1, 2 and 3 column pounding is carried out using the software ETABS and the corresponding torsional response is evaluated. The influence of separation gap and floor heights between the adjacent structures on the torsion effect is investigated and the results are compared with no pounding case.