The Study Of Torsion Model Test Of Self-anchored Suspension Bridge With Parallel Wire Main Cable

Main cable of spatial self-anchored suspension bridge in initial construction state is located in the vertical plane, while in the finished state it will to be spatial cable under the lateral tensile force of hanger. The main cable shape from plane to space conversion process, which between the two saddles will produce a certain twist because of constraint influence from saddle and cable clamp and tensile force of hanger. This paper based on the "Theory and Method of Adaptive Configuration and Effect of Coordinated Control of Spatial Cable Suspension Bridge" project of National Natural Science Fundation, at the background of JiangDong bridge in city of HangZhou, have used the combined method of ANSYS finite element model and experiment of entity model of spatial cable to make the research of section torsion characteristics considering parallel wire conversion process from plane state to the spatial state. Specific studies as follows:(1) Determining test scheme. Considering the effect of economy, model materials, fabrication processes and laboratory conditions, a model test is determined with a geometric scal of 1:15 by the geometric similarity principle. And the key member of the test model, test conditions and loading scheme are have been designed and made.(2) Researching the test treatment method. Installing three equal length flyswatters in the main cable key points and measuring the observation points space coordinate. At any space angle the linear and section torsion angle of parallel wire main cable can be calculated by the relationship between geometry position and rotation angle.(3) Theoretical study of the main cable section torsion angle. The two main aspects of the value of hanger inclination angle and the select of main cable torsional stiffness which impact on the parallel wire main cable torsion angle are analyzed, also have analyzed the value range and factors in the main cable torsional stiffness. The variation of main cable section torsion angle is studied through the establishment of parallel wire main cable torsion ANSYS finite element model.(4) Analyzing the measured data of main cable section torsion angle. By measuring each conditions main cable section torsion angle in the main cable key points, to analyze the impact of hanger force and inclination angle on the main cable section torsion angle under the situation of cable clamp installation and main cable torsional stiffness remains unchanged. Also the suggestions to construction control have been proposed in accordance with the model test results.(5) Comparative analysis the theoretical calculation and experimental results of the main cable section torsion angle. The theoretical results are compared with the measured data, which error reasons have analyzed combined with the actual situation, and also the torsional properties of parallel wire main cable are studied.These studies for the guidance of actual construction control and establishment of spatital cable torsional property theories and methods are provided a certain reference value.