Research On Analysis Method Of Self-anchored Suspension Bridge Formation Process

The self-anchored suspension bridge is a suspension bridge that relies on stiffening beams to bear the horizontal component of the axial force of main cable.It can be applied to build a suspension bridge without ground anchors,thus it is becoming more and more attractive.Although the appearance of self-anchored suspension bridges are similar to ground-anchored suspension bridges,the mechanical function of stiffening beam and mechanical performance are different from each other,especially the construction method.Ground-anchored suspension bridges usually constructs the cable and then the stiffening beam,while self-anchored suspension bridges need to anchor their main cables to the stiffening beam,so they usually constructs the bridge deck before main cable.Therefore,there are several system conversitons in the construction of self-anchored suspension bridge,so that the construction control is more difficult than that of suspension bridge.Hence,it is necessary to explore the unique system conversion analysis method of selfanchored suspension bridge to improve its structural control accuracy,and to ensure the actual state of structures accord well with the corresponding target state.Therefore,it is of important scientific significance and significant social and economic benefits to improve the coincidence between the design state and actual state of self-anchored suspension bridge.According to the requirements of construction control of self-anchored suspension bridge,this paper studies the analysis method for its construction control.Firstly,the main cable catenary equation corresponding to the target state of the self-anchored suspension bridge is further simplied and derived to obtain the relationship between the design parameters of main cable,and the target bridge state of the structure is analyzed and optimized by numerical analysis;Then,an improved algorithm is proposed to improve the accuracy of construction control algorithm for self-anchored suspension bridge by analyzing the defects of the current unstressed state analysis method and the retrogression analysis method.Subsequently,the creep effect of the concrete self-anchored suspension bridge is studied,and a forward and backward method is proposed to analyze the completion process of self-anchored suspension bridge.Finally,the influence of uneven lateral force on the structural mechanical performance caused by the unsynchronized tension of hangers is carried out.The main research contents include:(1)The target structure state analysis method of self-anchored suspension bridge during bridge completion.Based on the theoretical equation of the segmented catenary of the main cable,it is simplified and solved,and a method for calculating the reasonable target completion state of a self-anchored suspension bridge is proposed.The vertical component of the segment and the stress-free length are characterized,thereby reducing the number of unknown iteration parameters to 1,thereby improving the calculation efficiency of the structure.The model was applied to the internal force calculation of the target state of the Egongyan track special bridge and compared with the calculation results of its analysis report.It was found that the analysis results of the two were consistent with the change trend,thus verifying the accuracy of the model.(2)The calculation method of self-anchored suspension bridge completion process control.Based on the structure-based retrogression analysis theory and the internal force state of the main cable during the completion of the self-anchored suspension bridge,the defects of the current unstressed state analysis method and retrogression analysis method are pointed out,and the self-anchored suspension bridge completion process control calculation method is proposed to solve In the process of bridge completion,the problem that the results of the retrograde analysis and the analysis of the front installation are not closed,the method is applied to the full bridge model test of the Taohuayu Yellow River Bridge and the analysis of the completion process of the Egongyan track special bridge,and the test results and structural design values The calculation method of the bridge process control is verified by comparison.(3)Iteration and retrogression analysis of the shrinkage and creep effect of the concrete of the stiffening beam during the completion of the self-anchored suspension bridge.An iterative analysis method for forward installation based on the internal force of concrete is proposed,which solves the problem that the iterative method of unstressed state of slings cannot effectively and accurately control the shape of stiffening beams and bridge towers.A retrospective analysis method of concrete shrinkage and creep effects is proposed,and it is applied to retrospective analysis of concrete self-anchored suspension bridges during completion.An engineering example of the Wanxin Bridge in Fushun,Liaoning,verified the iterative and retrogressive analysis methods of the concrete shrinkage and creep effects.The error between the forward-fitting iterative analysis method and the target state of the bridge is within 1%,and the difference between the retrogression analysis of the bridge completion process and the normal-fitting analysis is within 3%.(4)Analysis of the influence of uneven lateral suspension cable force during the completion of the self-anchored suspension bridge.Combining the influence of the cable force between adjacent slings of a self-anchored suspension bridge with the analysis theory of lateral load action,the self-anchored suspension bridge is subjected to uneven lateral force caused by the unsynchronized sling tension during the completion of the bridge.Research and put forward suggestions for the reasonable setting of sling spacing of self-anchored suspension bridges.