Road network is still the primary transportation system in Nepal, and bridges are the most sensitive part of that system. Most of the bridges were constructed about 40-50 years ago based on the design life of 50 years and traffic forecast for 30 years. The design was based on an allowable stress method where a small value of seismic design force was considered. Therefore, it is necessary to evaluate the seismic performance for the continuous use of an existing bridge. The structure was evaluated separately for the allowable stress method and ultimate capacity method as per the revised code. The seismic performance of the bridge was then estimated with the Capacity Spectrum Method and the Response History Analysis. These analyses imply that the structure has enough capacity to meet the seismic demand as per the revised code or when the double lane standard deck replaces the existing one. However, the failure mode is a shear failure, so retrofitting should be done for the continuous use of an existing structure.
Keywords: Allowable stress, Ultimate capacity design, Steel jacketing, Non-linear earthquake responses.