many recent researches have been devoted to investigating the connection between seismic activity and ionospheric variations. it has been shown that the behavior of characteristic parameters of the ionosphere can be used as temporal and spatial precursors of strong earthquakes ( ). in the present work variations of critical frequency of ionospheric f2 layer as a temporal precursor for the qom e...

The seismic response of bridges seismically isolated by lead-rubber bearings (LRB) to earthquake excitations of different magnitudes is presented in this thesis. The force-deformation behavior of LRB is considered as bilinear. The specific purpose of the study is to assess the effect of seismic isolation on the peak response of bridges subjected to different base accelerations ranging from 0.05...