Seismic Performance Research Of Cross Beam Structure On Main Tower Of Suspension Bridge In The Region Of High Earthquake Intensity

This paper relies on western traffic construction project of science and technology“Key technologies research on kilometer of large span suspension bridge in Yunnanstrong earthquake area”, For the main tower of the suspension bridge in the highintensity earthquake region, we carry out our research of the performance of rhestructure of the main tower in the seismic aspect.In our research we find that through the high intensity fortification,, shearproperties of the lower beam of the main tower in Baoshan shore is very weak, it cannot realiz of the effect of the structure" strong shear weak bending ductility design"under transverse earthquake. To solve this problem, we do our research mainly on twoaspects：First，by changing By changing the size and type of the cross section of lowerbeam, we improve the beam shear capacity directly.Our research shows that change thetraditional single cell box section into a single box double room section is a veryeffective method. Secondly,by imposing additional different forms of the beam (onetype, X type, K type)through the bottom of main tower, reducing force on the beam, itcan enhance shear bearing capacity of the lower beam indirectly. The research showsthat adding X type beam is the best scheme, K type is in the second place and oneword type is worst.The result of this research shows that: Considering from the ductility of thestructure，among various Schemes which Improve the beam shear capacity，theScheme which replace The beam cross section form from the traditional single cell boxsection into a single box double room section is most effective.