Parametric Analysis on the Stability of Long-Span Rigid-Frame Bridge during Cantilever Construction

Aiming at the stability of long-span prestressed concrete rigid-frame bridge during its cantilever construction,this paper investigates the effects of several dominant factors on the stability by means of the buckling theory,the deflection theory,the elasticity-plasticity theory and the collapse theory.Such factors are geometric nonlinearity,material nonlinearity,geometric imperfection,concrete crush,concrete crack,aggregate interlocking,etc.The effects of the initial pier deflection,the construction load type and the rigidity of tied-beam on the stability of long-span prestressed concrete rigid-frame bridge during cantilever construction phase are discussed in detail.Analysis and study results show that the mechanical characteristics of reinforced concrete have significant impact on the stability of long-span prestressed concrete rigid-frame bridge during cantilever construction phase.Structure stability coefficient decreases with the increase of the initial pier deflection according to parabola curves.The relationship between the rigidity of tied-beam and structure stability coefficient is in index curve.The unsymmetrical construction loads is dangerous to the stability of long-span prestressed concrete rigid-frame bridge during cantilever construction phase.