Experimental Research On Spatial Cable Torsion Properties And Torsion Effect For Self-anchored Suspension Bridge

When converting self-anchored suspension bridge with spatial cable from initial construction state to finished dead state, because of the three-dimensional sling force in different directions with different values and the constraining force between the saddles and sling clamps, the main cable between the two saddles would be under certain torsion. This torsion would cause the preformed angle lofting accuracy of the sling clamp. Then constructing difficulties and prolonged period would be made for the real time adjustment.This thesis, based on the national natural science funds subject “Theory and Method of Adaptive Configuration and Effect of Coordinated Control of Spatial Cable Suspension Bridge”, taking Hangzhou Jiangdong bridge as engineering background, has researched on the law of torsion properties and torsion effect of the section. The main content is as follow:(1)An experimental model proportion of 1:15 was determined in the consideration of economy, model material fabrication technology, and laboratory condition etc. The sling tensioning and anchoring system, the metrical equipment for cable configuration and the calculation method for main cable section torsion angle is introduced. And corresponding experimental scheme was made.(2)The spatial main cable FEA model in ANSYS was established to analyze the cause of the torsion. In theory, from two aspects: the torsional stiffness of the main cable section and the preformed transverse angle of the sling clamp, this part studied on spatial cable torsion properties and torsion effect.(3)This part analyzed the cause of positive twist and negative twist. Then, through the contrastive analysis with the measurement data of the directions of the sling forces and the angles of the sling clamps, proves the correctness of this theory.(4)This part is about the analysis of the measurement data of main cable section torsion angles. The key section torsion angles in different schemes were measured to analyze the influence of the section torsion angle caused by preformed transverse angle in different places.(5)A contrastive analysis about the calculation result in section torsion angle theory and the measurement data was done. Then, combined with actual conditions, this partanalyzes the cause of the errors, and studies the law of torsion properties and torsion effect.