Construction pre-camber analysis on steel-concrete composite beam of self-anchored suspension bridge

This paper summarized and evaluated the main beam construction methods of self-anchored suspension bridge, pointed out that the main-beam line would have a local depression between the largest span temporary pier when the steel-concrete composite beams were constructed by the incremental launching construction method, even if the main beam were withstand uniform boom-forces, moreover, the construction pre-camber curve of the main girder could not be arranged as a circle curve or quadratic parabola within the entire span. In view of this, the entire construction process of a self-anchored suspension bridge was analyzed by the finite element method, The results showed that the cross-section property changes of steel-concrete composite beam were the nature reason of the local depression on the main-beam line; The completed main beam was simplified into a three-span continuous beam which suffered vertical uniform distributing loads and horizontal forces at the two ends, and the simplified formulas of calculating the vertical displacement of each span were derived by the force method; The numerical example showed that, the proposed simplified formulas could effectively solve the affection by the cross-section property changes, accurately predicted the main beam cumulative vertical displacement, and the calculation accuracy could meet the engineering requirements. The conclusions of this paper had a strong guiding significance and reference value on the construction pre-camber design of the bridge with the similar structural type.