Asymmetric seismic pounding between multistorey reinforced concrete structures in a city block

Usually within city blocks land ownerships are not equal and exhibit various geometries. Therefore, it is most probable adjacent structures to be partly and in an asymmetric way in contact. Consequently, buildings asymmetrically restrained in lateral displacements during earthquake excitations carry out torsional oscillations. The interaction of an 8-storey reinforced concrete frame building designed according to Eurocodes with an adjoining structure for various parameters is thoroughly investigated. The 8-storey frame is considered with pilotis configuration and fully infilled whereas the other structure is studied for the cases of 6-stories, 3-stories and single storey. Further the two interacting structures form an L-shape plan and are studied for three cases of asymmetric contact, whereas two natural seismic excitations each one applied in two directions (positive - negative). Thereupon, for the thorough study of the problem more than 100 pounding pairs for structures having equal storey levels (floor-to-floor pounding) and 100 pairs for structures having unequal storey levels (floor-tocolumn or interstorey pounding) have been investigated. The whole study highlights crucial aspects of the issue such as the unfavourable role of pilotis configuration, the significant torsional vibrations induced and the almost inevitable shear failure of columns that suffer an impact by an adjacent building within their deformable height.