Study On Asymmetric Coefficient And Construction Control Of Asymmetric Continuous Rigid-Frame Bridge

Continuous rigid frame bridge is characterized by convenient construction, low construction price and suitable for mountain areas. Thus it has been widely applied in highway construction in mountain areas. However in "U" shape and "V" shape valley which is common in mountain areas, the terrace of each side of valley is asymmetric, which cause significant trouble for common symmetric layout of continuous rigid frame bridge, thus the continuous rigid frame bridge with huge asymmetry in pier height or span length are proposed.Sinan Yantou river bridge which is already completed is a continuous rigid frame bridge with asymmetry in both pier height and span length. This paper adopt Sinan Yantou river bridge as its engineering background, study the construction control reasonableness. This paper introduces the asymmetry coefficient and analyzes the limit value of this coefficient. The major work of this paper includeBy study large quantity of continues rigid bridge construction control example, this paper conscientiously sum up the content of construction control, elaborate the theory and methods of construction, summarized the major element which affect the construction control efficiency.Build full bridge model of Sinan Yantou river bridge by Midas/Civil, simulate the contraction process and calculate the internal force based on forward-calculation methodTake the elevation and stress of cantilever section as control objectives; determine the correctness of control method by comparing the measured value and calculation value.Expand the larger T frame into symmetric frame, remove 20 cantilever sections one by one on left T frame according to construction sequence, form the models with different asymmetry coefficient. By studying the variation of support reaction, stress and deflection of models with different asymmetry coefficient, the reasonable numerical value range of asymmetry coefficient has been determined.