Plastic hinge analysis of long-span rigid frame bridge

The formation and development of plastic hinge have a great influence on the seismic response of long-span rigid frame bridges. Therefore, it's especially important to study the development process of plastic hinges under ground motion. Based on the OpenSees software, the elastic-plastic finite element model of long-span rigid frame bridge is established, the influence of pier design parameters on plastic hinge is studied from the perspective of IDA analysis. Meanwhile, the advantages and disadvantages of lumped plastic hinge and distributed plastic hinge are discussed in two groups of bending failure pier of "Pseudo-static test on bridge pier of chengdu-lanzhou railway". The results show that the accuracy of distributed plastic hinge element simulation is higher than lumped plastic hinge; and with the increase of pier height and longitudinal reinforcement ratio, the PGA with plastic hinge in the section will increase for the first time.