Research On Construction Control Of Cantilevering Casting Construction Of Long-span RC Arch Bridge

Reinforced concrete arch bridge is the most outstanding in all bridge,no matterfrom the structure behave and durability.With the development of society,therequirements of the bridge become more and more high, the span of bridges are gettingmore and more long.And reinforced concrete arch bridge is one of the most potentialbridge development to long span beidge.In the experience of Chinese trafficdevelopment in the past thirty years,the key of the breakthrough in arch bridge’ span isthe construction technology.And in the weatern region of China,bridge across the ditchor valley become more and more common,the study of arch bidge’s new constructiontechnology have positive significance to the career of traffic.Arch construction to bebuilt entirely by cantilever erection method with cable stays become very commonabroad,but in our country just have only one which is Baisaguo1#bridge constructedby this method,and the research of this aspect is very little,we have a lots of problems tobe solved.This paper focus on this subject, made the following work:①Collect and research the theory and method of cantilever construction ofreinforced concrete arch bridge at home and abroad, the data show that the length ofcantilever segment during the process of cantilever casting is generally set to near thearch of the foot stage is larger than near the vault segment,near the arch of the foot partof the cantilever length up to12m or so, but divided into two sub pouring;near the domepart of the segment length of5~6m.If the cantilever pouring segment length is set toolong will take difficulties to construction,and quality and safety can not be guaranteed.②Introduced several currently used calculate method of buckle cable force buringconstruction process,and compare the pros and cons of various methods and, whereapplicable.Pointed out that most of the assumptions of the calculation method does notmatch with the actual situation or the calculation process is too complex and are toocomputationally intensive, and other shortcomings,thus introduced the zero orderoptimization method and the first order optimization method theory,and modules andoperational processes which ANSYS provide of the zero order optimization method andthe first order optimization method.③Using ANSYS zero order optimization method module,bending strain of thering structure in the entire construction process as the objective function,buckle cableforce as the design variables,maximum tensile stress to the arch cross section during theconstruction process as the state variables,arch section segment cable stayed buckle hanging cantilever placement and construction phase to buckle cable tensionoptimization.Compare thecalculation results of taking into account and excluding thebuckle tower.Analysis of the former fulcrum cradle construction of maximum tensilestress on the ring structure.