EVALUATION OF RC BRIDGE PIER DESIGNED AS PER DIFFERENT SEISMIC CODES

Abstract

Reinforced concrete (RC) bridges are potentially among the most seismically vulnerable structures. The damage of RC columns in regions that experience inelastic action depends on the characteristics of the earthquakes as well as column details. In some major earthquakes in the past, a large number of bridges suffered damages and collapsed due to failure of foundation (structural and geotechnical) and substructure. The failure of substructures occurs due to poorly configured and widely spaced transverse reinforcement. The insufficient lateral resistance along with poor detailing of reinforcement is the main reasons for inadequate seismic performance of the structure. It is necessary to determine the seismic capacity/demand ratio of RC bridge pier. Seismic performance of reinforced concrete bridge pier is strongly influenced by amount, spacing and details of confining steel as well as longitudinal reinforcement details. The thesis is concerned with the behavior of reinforced-concrete bridge pier in earthquake conditions. In the present study, five span simply supported T-beam RC girder bridges are considered. The substructure consists of hammerhead bridge pier designed as per IS: 456-2000. The bridge is situated in zone V and its seismic design is carried as per IS: 1893-2002 specifications. The transverse reinforcement of RC bridge pier is designed as per AASHTO, New Zealand, Japanese Road Association, IRC: 21-2000 and IS: 13920-2002 specifications. The effect of axial load level, pier geometry and pier slenderness on the capacity and demand of pier is carried out. Seismic evaluation of the designed RC bridge pier is carried out with nonlinear static (pushover) analysis using SAP2000 software. The main goal of the present study is to determine the capacity/demand ratio of RC bridge pier. The result includes comparison of shear capacity and shear demand for RC bridge pier designed as per different seismic codes. The results include the comparison of pushover curves for effect of axial load level, pier geometry and pier slenderness. The results include the ratio of transverse reinforcement required for seismic event and transverse reinforcement provided as per code.