Study On Anti-seismic Performance Of Super-span Suspension Bridge

The construction level of super-span suspension bridges to a great extent reflects anation’s bridge construction level. The21st century will be a big leap across the super-spansuspension bridge construction development period. According to relevant experts predict,our country is facing new seismic activity cycles. But super-span suspension bridge cost ofconstruction is high, structure damage will be a bigger impact to traffic and economic,super-span suspension bridge’s seismic response is complex, seismic design are particularlyimportant. Study the super-span suspension bridge’s seismic performance has greateconomical benefits and social significance.This paper established main span of2000m,3000m’s super-span suspension bridgethrough suspension bridge assistant. Select four Seismic waves, respectively incentive thebridges from a different direction, analysis different excitation seismic response. And thenchanged some structural parameters of super-span suspension bridges: the ratio of the edgespan and main span, the cable stiffness, the central buckle settings etc. Examine structuralparameters change to the seismic performance’s influence of the bridge. Through the analysisfound that, the ratio of the edge span and main span is0.45, the suspension bridge seismicresistance is more favorable; relative cable rigidity coefficient is1.5, the anti-seismic propertyis better. When bridge site are very easy to occur earthquake along the bridge, the centralbuckle settings is most favorable to the suspension bridge. But when the horizontalearthquake happened, it to structure’s anti-seismic is retroaction.This paper finally investigation super-span suspension bridge’s structure form changes toseismic performance influence. Using the level cross sling, vertical cross sling, mixed crosssling and space cable structure forms. Analysis seismic response of different structures forms,through the analysis found that: when the vibration direction is different, different structureforms of suspension bridge, the seismic performance has its own advantages anddisadvantages. The space cable suspension bridge their damping effect is not obvious.Analyzing the long-period ground motion occurrence mechanism,using long cycle seismicwaves-when chuan seismic wave across the super-span suspension bridge by time history analysis. Analysis found that the long period seismic wave has remarkable influence to longperiod structure of super-span suspension bridges.When bridge location easy to occurlong-period ground motion, must consider the long cycle seismic wave’s adverse impact tobridge structures.