Structural Modelling of Reinforced Concrete Slabs Under Vertical Ground Motion

According to modern seismic codes, in certain cases, the vertical component of the ground motion has to be taken into account. However, no specific instructions concerning the structural modelling—and especially the modelling of vertical masses—are provided. The objective of the present paper is the evaluation of alternative structural models of reinforced concrete slabs under vertical seismic excitation. For this purpose, a series of single-storey buildings were analysed by means of linear and nonlinear time-history analysis and the values of representative response quantities were calculated. The influence of several parameters such as the dimensions and the shape of the slabs, the existence of openings, the distribution of the vertical load, the type of the seismic excitations and the analysis method was investigated. The whole evaluation study led to the derivation of useful conclusions.