Seismic Response Analysis Of Long-span Cable-stayed Combination With Rigid-framed System Bridge

As one of the cable systems, the cable-stayed bridge has more span capacity than girderbridge, and it is also one of the most important bridge styles in long-span bridges. With theincrease of the span, overall flexibility and the complexity of the structure, the study ofseismic response of the long-span cable-stayed bridge is the most concerned about and themost challenging issue in bridge engineering industry. The instance bridge which this paperanalyzes is the new system bridge which cooperative with rigid-framed, the structure iscomplicated and what is more, this bridge is in traffic arteries location, so it is very necessaryto analysis the seismic response of this bridge. On the basis of the Summarizes of the researchresults in domestic and foreign, this paper has done a systematic research and analysis on thedynamic characteristics and the seismic response. This paper established a spatial finiteelement model of the bridge which is finished by finite element analysis software MIDASbased on the theory of finite element, and considered the impact of the pile-soil-structureinteraction on structural dynamic characteristics. Its results indicated that thepile-soil-structure interaction has significant influence on the dynamic characteristics.According to the Instance bridge structure and site characteristics, this paper selects thecorresponding coefficient such as seismic acceleration、 site classification, and finallydetermines the response spectrum curve,and analysis the response spectrum by imputing thecurve along the longitudinal transverse and multidimensional direction-horizontal combinedvertical. Its results indicated that vertical seismic component have a great impact on thestructure. So vertical ground motions cannot be ignored in the cable-stayed bridge seismicdesign. As the response spectral analysis is linear and the nonlinear factors can`t be taken intoaccount, so this paper chooses the EI-Centro earthquake wave to analysis the seismic responseof the instance bridge with the dynamic time-history analysis which can consider theinfluence of geometrical nonlinear on the long-span flexible structure. Compared the resultsof time-history analysis and the response spectrum analysis, we knew that the calculationresults of response spectrum were bigger, so seismic checking computations should becombined with the time-history analysis. The conclusions of this paper can be used as thebasis of seismic design of such kinds bridge and is useful for directing seismic responseanalysis of other kinds bridge.