Analysis And Research On Key Technologies Of Self-anchored Suspension Bridge

In recent years,self-anchored suspension bridge has been favored by many people for its meits such as graceful appearance,strong adaptability to topography and geology,good economic performance and so on.Due to the changes of anchorage methods,the self-anchored suspension bridge is more complex than the traditional anchored suspension bridge in terms of structural stress and construction control.Based on Fuyang Quanhe Bridge,this thesis analyzes and studies the key technologies of the self-anchored suspension bridge such as the rational completion status,main cable shapefinding and system conversion and so on by adopting the general finite element program MIDAS/CIVIL and the large mathematical software MATLAB.The major research contents are as follows:(1)The calculation theory of main cable shape-finding is analyzed,and the cable shape of parabolic theory,catenary theory and segmental catenary theory are deduced.On the basis of segmental catenary theory,the calculation method of main cable shape for the completion state of bridge and empty cable state is analyzed.According to the mechanical relationship and geometric conditions of the main cable at the saddle,the nonlinear equations of the exact calculation of the position of the saddle are established.The position of the saddle and the tangent point of the saddle are calculated,and the unstressed length of the main cable at the saddle are corrected.(2)A calculation method for determining the rational completion status of self-anchored suspension bridge is put forward.Based on the least bending energy method and the segmental catenary method,the equilibrium of force and deformation compatibility conditions of the main cable and stiffening beam at the connection are considered,and several iterative computations are carried out until convergence with the help of the finite element software,and a reasonable bridge state is finally obtained.(3)Based on the rational completion status,the nonlinear finite element method is applied to analyze the main cable shape of the completion state of bridge and empty cable state.In view of the accurate calculation principle of saddle position,the predeflection of saddle and saddle tangent point are further determined,and the unstressed length of main cable at the saddle is corrected.(4)On the basis of the proposed tensioning construction scheme of hanger,unstressed state method is applied to study the variation law of cable forces and main cable internal forces in the process of system transformation,which provides theoretical basis for bridge construction control.