Evaluation of the applicability of simplified single-mode spectral analysis in the preliminary seismic design of isolated bridge according to TCVN 11823:2017

Abstract

Earthquakes are one of the factors that cause a lot of damages to people and social property, especially to essential infrastructure such as bridges. Seismic isolation bearings are considered an effective seismic design solution, especially widely applied for bridge structures, and offer high efficiency in structural protection. The design calculation of seismic bearings for bridge structures is mentioned in world standards, but not clearly specified in TCVN 11823:2017. This paper presents a simplified analysis method for the fundamental vibration mode of bridges applied in the preliminary design of seismic isolation bearings, calculated according to TCVN 11823:2017. The reliability of the simplified method is evaluated by comparing the analysis results with the nonlinear time-history analysis method. The obtained results allow for providing necessary suggestions for design engineers in applying seismic isolation calculations, contributing to the development of standards for the seismic-resistant design of bridges in Vietnam.