The Ductility and Performance Assessment of the Towers of Bheri River Suspension Bridge Using a Performance-Based Pushover Analysis
Keywords:
Suspension Bridge, VIB Sensor; Model Validation, Free Vibration Analysis, Push Over AnalysisAbstract
Bridges play a crucial role in the infrastructure of every nation and serve as a vital tool for development. Among the various types of bridges, suspension bridges may be a favorable option for constructing over large and major rivers in Nepal, taking into account aesthetic, geological, environmental, economic factors. As lifeline structures, bridges must remain functional even after an earthquake. Given that Nepal is located in a seismically active belt, major earthquakes occur frequently. To evaluate the seismic performance of a suspension bridge, finite element software (CSI BRIDGE) was used. The study focused on the Bheri River suspension bridge in BirendranagarSurkhet. Various time histories were applied, scaled to match IS code Response spectra, the resulting forces and displacements were examined. The model was analyzed through free vibration, non-linear static (pushover), linear dynamic (time history) analyses to determine capacity and demand. To evaluate the proposed model’s adequacy, the natural frequencies and associated mode shapes predicted by the model were compared to the ambient frequency obtained from a VibSensor,an ISO-certified smartphone application. Response quantities such as induced displacements and straining actions were also presented. with FFT and empirical formulas for the first three modes and the first 20 natural frequencies. The pushover analysis of the tower provided ductility values of 5.37 and 5.42 in the transverse and longitudinal directions, respectively. Performance-based pushover analysis showed that the tower reached the Immediate Occupancy level in MCE.
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