The effects of the duration, intensity and magnitude of far-fault earthquakes in seismic retrofitting an RC bridge

Abstract

This paper investigated the effects of the duration, intensity, and magnitude of earthquakes in seismic retrofitting of RC bridges using seismic bearings. First, the seismic retrofit of an RC bridge using seismic bearings under the Tabas earthquake was investigated. Seismic bearings included elastomeric bearing (EB), lead rubber bearing (LRB), and friction pendulum bearing (FPB). In order to investigate the effects of this equipment, the condition of the deck with a rigid connection on the cap beams and abutments was investigated in another model. The results of the studies showed that the use of seismic bearings leads to seismic retrofit of the studied bridge, and FPB and LRB had the best results among the studied equipment, respectively. The same models were studied subjected to the Landers earthquake. The magnitude is equal to Landers and Tabas earthquakes, but the duration and intensity of the Landers earthquake are much larger than Tabas earthquake. The Landers earthquake caused instability of isolated models due to its significant duration and intensity. This issue indicates that in the far region of faults, considering the duration and intensity of earthquakes is very important to seismic retrofit of bridges using seismic bearings. Also, magnitude as the only criterion for selecting earthquakes is not suitable for seismic design and retrofit of bridges.