Analysis Of The Parameters Having Influences On Geometry Of Main Cable Of Long-span Suspension Bridge

The erection precision of the suspension bridge main cable shape is the decisive factorof the quality and service life of the suspension bridge, but the alignment of the bridge isclosely related to the main cable shape. Therefore, in this paper in order to improve theaccuracy of the main cable shape as the goal, it is necessary to study and analysis about theeffective parameters of the alignment of the bridge and the related effective parameters in theprocess of the main cable.Firstly, this paper gives a brief introduction to the main parameters that influence the shapeof the main cable. Some parameters that influence the alignment of the bridge include theelastic modulus of main cable, cable cross-sectional area, cable weight, but other parameterswhich influence the main cable shape consist of the elastic modulus of main cable,temperature effect, saddles and cable porosity. Secondly, in this paper, it bases on a selfanchored suspension bridge object which is in the construction, then through establishing thefinite element model of MIDAS/CIVIL to analysis and calculate the influence ofthese parameters with different scheme. Then through doing curve fitting about the results ofthe numerical it can show that:①the unstressed length of the main cable with the elasticmodulus of main cable and cable weight show a linear relationship, but shows twotimes parabola relationship with the cable cross-sectional area;②vertical coordinate at themiddle of the span at the free cable status shows a parabola relationship with the elasticmodulus, but a linear relationship with the effect of temperature and Influences of porosityof the main cable. Finally, with analysis available:①the errors of cable elastic modulus andcross-sectional area make little difference on unstressed length of the cable, while the weightof itself influence strand relatively large;②the modulus of elasticity and temperature effectsexert greater impact on the main cable shape, less affected by porosity;③saddles must betake into consideration while calculating owing to its big difference on saddles of emptyshape.This paper analyzes the influence of some parameters about the main cable shape of thesuspension bridge, and some conclusions are drawn, which can provide some reference forthe manufacturing of the cable and construction monitoring of the suspension bridge.