Research On Fine Construction Control Of Self Anchored Suspension Bridge

In recent years,more and more self-anchored suspension bridges have been built in China,because they do not need huge anchorage and have beautiful shape.The sectional catenary method does not take influence of cable clamp on the overall alignment and system transformation process in account,but it is actually affected by the main cable span,cable stiffness,cable clamp form and other factors.The traditional calculation method may have some calculation errors,so it is necessary to study the fine construction control.The main contents of this paper are:Firstly,based on the segmented catenary theory,a method for calculating the main cable profile considering the clamp effect is proposed and implemented by Fortran program.Under the condition of keeping the ratio of rise to span and other factors unchanged,the influence of cable clamp on the main cable shape is considered,and the stress-free length of the main cable is compared whether the influence of cable clamp is considered or not.Then,under the condition of keeping the ratio of rise to span and other factors unchanged,the influence of cable clamp on the alignment of finished bridge is obtained by adjusting the force of cable and the length of cable without stress when considering the influence of cable clamp.In addition,the influence of the bending stiffness of the cable clip and the main cable on the main cable line shape is obtained by comparison,and the influence of the bending stiffness of the main cable on the stress-free length of the suspension cable is considered when the suspension force is consistent.Finally,during the whole system transformation process of self-anchored suspension bridge,the main cable shape,suspension force,main tower offset and other monitoring are realized,and the predetermined system transformation is realized through twice suspension cable tensioning.The stress of the special section near the clamp of the main cable in the process of system transformation is tested,and the concrete value and variation rule of the secondary stress of the main cable at the clamp outlet are obtained,which provides the experimental data for the later study of the secondary stress of the main cable.