| With the continuous construction of the crossing-river and crossing-seaengineering all over the world, the bridge research is developing towards larger span,more reasonable force, and less costs. In this case, reinforced concrete arch bridge isfavored by bridge engineers on account of its large spanning ability, simple force-transferring mechanism and low costs of the project and maintenance. WanzhouYangtze River Bridge in Chongqing, a reinforced concrete arch bridge with420m ofmain span, is the one with the largest span in the world. Feasibility research on600-1000m large span reinforced concrete arch bridge has been done in Europe, Japan,Croatia and so on and some research results have been achieved.This thesis takes the reinforced concrete arch bridge with600m of main span trial-designed by Architectural Association of Japan in1999as research object with the goalof probing into the seismic capacity of this kind of arch bridge through accomplishingthe following tasks:â‘ An elastic analysis model of structure is established to research into thedynamic characteristics of the arch bridge itself. And8typical seismic waves areselected to conduct non-synchronizing input, extract response parameters of structurecontrol point, and analyze how the seismic frequency characteristics andacceleration peak value emit its effects on travelling wave effect. And thus the authorholds that the effects of travelling effect on the seismic response of the arch bridge cannot be ignored.â‘¡A nonlinear analysis model is established on the elastic analysis model, useIDA to conduct the time history input of travelling wave effect, and extract the relevantparameters of seismic response including the control point displacement, control pointacceleration, control section internal force and control section deformation to find outhow the parameters change with seismic intensity and make an initial assessment thatthe position of the arch foot, the1/4span and3/4span of the arch bridge should be themain object of the vulnerability assessment of the large span reinforced concrete archbridge under seismic effect.â‘¢At last, the method of capacity demand is used to analyze the principles of theseismic resistance of structure and the moment-force time history curve and themoment-force relevant curve of the cross-section of arch springing are compared to find out how the seismic internal force responses of the cross-section of arch springingchange with the increase of the seismic intensity. Through calculating the capacitydemand ratio of the internal force of the cross-section of the arch springing, the authorconcludes that the arch foot is the weak position of this bridge under seismic bridge andthe later-stimulated side of the arch foot is more likely to be destroyed than the early-stimulated side of the arch foot, with the internal force capacity demand ration of theformer one being1/3to1/2of the later one. |
