Seismic Response of Brick Buildings with Sliding Substructure

Abstract

To investigate the ground motion isolation feasibility, a new brick building system is considered here in which a clear smoothened surface is created at plinth level just above the damp‐proof course, and the superstructure simply rests at this level and is free to slide, except for frictional resistance. Pilot tests carried out on one‐fourth scale brick building models showed large reductions in the roof acceleration compared to conventional fixed‐base models that are subject to shake table motion, indicating a possibility of earthquake isolation. The seismic response of single‐story sliding buildings, subjected to Koyna and El Centro accelerograms, is computed through a two‐mass spring dashpot mathematical model that treats the frictional resistance as rigid plastic. This study leads us to a concept of frictional response spectra, on which the spectral quantities of the sliding system are plotted against the undamped natural period for various coefficients of friction and mass ratios. These spectra clearly show the reduction of response of the sliding system compared to the conventional building.