Study On The Reasonable Completed State And Most Optimized Cable Force During Construction Of Mati River Bridge

Using cantilevering method to build concrete arch bridge started later than foreign country and there are only five bridges completed in China and the largest bridge spanned 200 m.Foreign countries has reached the maximum span 323 m using ultra-high concrete.With the arch cantilever construction process in the country and continue to use mature development of structural analysis theory of reinforced concrete arch bridge cantilever pouring construction method will certainly span to greater development.Mati River Bridge in Guizhou is the largest span arch bridge built in the highway,the suspension poured and hanging basket is heavier,since the major construction process control of the buckle cable force,arch stress,buckle tower and other aspects of a more strict.This paper takes Mati River bridge as engineering background,mainly does the following studies:1.Firstly,the article summarized the development status and research status of concrete arch bridges with cantilevering method.It did the basic research to the development of large-span arch bridge with cantilevering method.2.According to the force features of arch bridges,it created a nonlinear programming mathematical model of cable force adjustment before the closure of concrete arch.Combined with numerical analysis software Matlab optimization toolbox provided,it gave the solving process and corresponding Matlab solving programming.And it took feasible region of constant load as the referring conditions to judging the reasonable completed state.According to comparing the results of Mati River bridge before and after optimization,it verified the mathematical model’s correctness.3.It took Mati River bridge as the engineering background and the linear and internal force during the construction process as the main control target.Aiming at the characteristic that arch stress could not be ignored after the cradle moving for some segments,this paper introduced “Zero displacement method” and “Stress balance method” combining method to solve the reasonable cable force during construction.The results showed that the method is feasible to the arch bridges with cantilevering method using cradle of larger weight.4.It derived the relations between arch deformation of construction and buckle cable area,anchor area,height of point deduction and the bending stiffness of buckling tower.Besides,the paper put forward the concept of suspension pouring deflection impact factor ‘η’,and on this basis,it showed the buckling tower cable point optimization method through the example of Mati River bridge.What’s more,it analysed the affection on construction cable force after the optimization of buckling tower cable points’ height of Mati River bridge.