Three-tower Cable-stayed Bridge Semi-suspension System Seismic Response Analysis

In recent decades, cable-stayed bridge with beautiful shape, low cost, goodperformance has gained more and more popularity and become one of the mostcompetitive modern bridges. With the development of the technology, the span ofcable-stayed bridge is constantly increasing. As the hinge of transportation, cable-stayedbridge is invested a lot. If once destroyed in an earthquake, it will cause huge damagesto the economics and safety, and also seriously affect disaster relief and post-disasterreconstruction. Therefore, the study on the seismic performance of cable-stayed bridgehas become increasingly important.On the basis of the previously relevant researches at home and abroad, this paperhas applied midas/civil to build the space model of bridges on the engineeringbackground of three-tower cable-stayed bridge semi-suspension system, and analyzedthe dynamic characteristics of the structure as well as its seismic response with theresponse spectrum method and time-history method. In the analysis of responsespectrum, the maximum of displacements and internal forces is attained taking theone-way, two-way and three-way earthquake combinations into consideration and thenthose combinations are mutually compared. When conducting time-history analysis, thispaper studies the influence of uniform excitation and non-uniform excitation on theseismic response analysis of the cable-stayed bridge. Meanwhile, the paper comparesthe response spectrum method and time history method and finds that the changes ofcable-stayed bridge’s displacements and internal forces in the analysis of time-history isconsistent with those in the response spectrum analysis, however, the results of thetime-history analysis method are smaller but not less than80%than those of theresponse spectrum method.Through the above studies, some useful conclusions are reached and some unresolvedissues in the future researches are further illustrated.