SEISMIC ANALYSIS OF BRIDGE BEARINGS USING DIFFERENT SHEAR MODULUS

Throughout seismic actions, several factors affect the behavior of RC bridges. The shear modulus of the elastomeric bearings pads is one of these most important factors. Elastomeric bearing pads are usually existed at the ends of the bridge superstructures to act as rigid constraints. The support boundary condition is defined by bearing pads and its existence can affect the seismic behavior of bridges. During this research, AASHTO design standards are used throughout this work. The bridges in this research were selected from actually executed in the Arab Republic of Egypt, according to the Egyptian code of practice [ECP, 2007], and located in the third seismic zone. The applied element method [AEM] is used to analyses the bridge models in this research the effect of changing the shear modulus of the bearing pads on the seismic behavior of RC T-Girder bridges is studied under a sever ground motion like Chi-Chi. The behavior of changing the bridge configuration is also studied. The research results showed that the seismic behavior of RC bridges it is highly affected by the value of shear modulus of the bearing pads and the existence of the bearing pads can isolate the seismic energy from the columns till failure