Analysis Of Self Anchored Suspension Bridge With Multi Tower Cable System Construction Process

The key construction control process of multi tower self anchored suspension bridge are empty cable and suspender tensioning.Uncertainty of tower-beam system,cable system and environmental temperature result in the difference of cable shape,affecting cable location during operation.Different from common suspension bridges,self anchored suspension bridge sling tensioning process needs conducting repeatedly.Because of the coupling between tower,beam,cable the support,it is hard to be solved.If you want to establish a reasonable tension scheme,you must take account of the safety of all those components,moreover the economics.In order to establish an reasonable bridge state,the finite element method is used and the analysis agree with the design well.The deviation of cable geometric is 15 mm and 3% of sling forces.Unstressed length of the main cable and slings are 4cm and 11 mm respectively.A detailed analysis is taken when considering about the cables,supports and environments,it shows that the most important factors are temperature changes,the vertical deflection of tower cable saddles,the vertical deflection of cable saddles located in girder and the location of anchorage system.The influence coefficient of each factor on the vertical deformation of the middle span of the free cable is given,and the method of fast look-up table is proposed to calculate the line shape of the cable.The adjustment of the length of the non stress length in the adjustment of the empty cable is given.Considering about sling stress state,the stress of the girder,Jack number,main cable and saddle the relative geometric position,cross-tower tension sling tension scheme is determined.To solve the optimal tension scheme,stress and deflection of tower,main cable saddle,the main cable deformation,contact conditions and construction stage cable force change are analyzed in detail on the hanger tower.The results show that the proposed scheme meets the control requirements.The study for self anchored suspension bridge with multi tower cable system construction process control has important reference and significance analysis.