Study On The Static Behavior And Seismic Response Of Composite Rigid Frame Bridge

The steel-concrete composite rigid frame bridges are widely used inhighway and railway projects for the advantages in strength, stiffness,construction, and economy, etc. In this dissertation, the static behavior andseismic response of composite rigid frame bridges which using RC piers andsteel-concrete composite beams were analyzed in OpenSees.Firstly, the static behavior of steel-concrete composite rigid framebridges was analyzed, including the use of double combination effect、 partialcombination effect、 prestressed technology and so on. Then parametricanalysis on them was also accomplished.The rigid frame bridges have better seismic behavior than most of theother bridges. In the seismic response research, pushover analysis of bothindependent bridge pier models and complete bridge models were respectivelyaccomplished. Then time history analysis was also done. According to thepushover analysis results and time history analysis results, the applicability ofpushover analysis was discussed. As a result, the pushover analysis method onthis kind of bridges was improved.Then the influence of directional uncertainty and bi-directionalhorizontal seismic excitations were investigated. For this purpose, severalbridge models with different parameters were established in OpenSees. Theseismic response of composite rigid frame bridges under bilateral andunilateral earthquake excitations were being compared with each other. At thesame time, the seismic response under different earthquake excitations wasdiscussed. Based on these results, methods of present specifications oncalculating the interaction between bilateral and unilateral earthquakeexcitations were evaluated. Further more, two practical methods to calculatethe largest displacement of composite rigid frame bridges under bi-directionalexcitations were summarized.In a word, this dissertation has summarized a practical pushover analysis method for steel-concrete composite rigid frame bridges and proposed twopractical methods to calculate the largest displacement of composite rigidframe bridges under bi-directional excitations, also a preliminary staticbehavior analysis has been accomplished.