Nonlinear Analysis And Comparison Of Hemudu Bridge

Cable-stayed bridge is a complex structural system，which makes up three basic componentsof main beam, cable and tower. In the small deformation analysis often ignore high order items ofdisplacement-strain relations. However, when the structure has relatively large geometricdeformation, displacement strain relationship is non-linear. The high order items shouldn’t beignored. Cable-stayed bridge shows geometric nonlinear behavior.This paper introduces the geometrically nonlinear finite element method and the processingmethod of cable-stayed bridge geometric nonlinear. Hemudu Bridge site to the engineeringbackground, construction stage model and space calculation model are established by the software.This paper select the19,24construction stage and bridge state of the two constant load and liveload stage, emphases are on analysis and comparison of the key parts of the displacement andinternal forces in the five calculation conditions. Based on the linear and nonlinear results arecompared, geometric nonlinear factors on the impact of Hemudu bridge in general are small. Themain reason is the bridge span is small and structure system is tower-beam consolidation system.The results show the most obvious influence on displacement, maximum of3.6%; on the bendingmoment influence in second, maximum of1.5%; the axial force on the impact of the minimum,only to a maximum of0.4%. Therefore the main span for less than150m concrete cable-stayedbridge should not consider geometric nonlinear effects.In order to better understand the different span cable-stayed bridge of nonlinear effects, thispaper selects four different span concrete cable-stayed bridge. By the comparison results, theeffects of geometric nonlinearity become more obvious with cable-stayed span increase. So toconsider geometric nonlinear effects is very important in the design and analysis of long-spancable-stayed bridge.Through the analysis of hemudu bridge’s vibration characteristics we can known: the firstfour order of natural vibration characteristics are lateral bending of bridge tower, it explains thelateral stiffness of bridge tower is small. The fundamental period of Hemudu Bridge, which istower-beam consolidation system, is obvious shorter, only1.35s.