Influence of Substructure Stiffness on Static Performance of Arch-beam Composite Bridge

With a practical engineering case,the simulation method for pile group foundation with equivalent column model considering the composite action of superstructure and substructure was introduced.Transformation formulas for the equivalent columns were given.On this basis,the influences of the changes of overall stiffness of superstructure and rotational stiffness of the group piles on the static performance of deck arch-beam composite bridge were studied.The result reveals that(1) the overall stiffness of the substructure has great influence on the bending moment of the main girder at the arch-beam combined segment and has less influence on axial force of the main girder;(2) the overall stiffness of the substructure influences both horizontal thrust force at completion stage and temperature caused horizontal thrust force greatly;(3) the rotational stiffness of the group piles has little influence on the internal forces at completion stage and has less influence on the thrust force at completion stage and temperature caused horizontal thrust force.