ANALYSIS OF OUT-OF-PLANE ELASTIC BUCKLING OF STANDARD CONCRETE FILLED STEEL TUBULAR TRUSS RIBS ARCH

Based on the statistical analysis of concrete filled steel tubular (CFST) truss arch bridges, considering the main structure parameters on its out-of-plane buckling, a virtual bridge is built and revised into a standard one by referring to two real bridges. The parameter analyses are conducted on this standard bridge by using the elastic buckling analysis method. The results show that the out-of-plane stability will be improved with the increase of the ratio of the width to span of the bridge and the decrease of the distances of the bracings; the X-shaped bracings have the largest improvement on the out-of-plane stability, followed by K-shaped and straight bracings; the stability becomes worse quickly with the increase of the out-of-plane slenderness from 80 to140, and then slowly from 140 to 220. Finally, the elastic buckling analysis method by solving the eigenvalue is discussed. Discussion results indicates that the load condition in the calculation should be the case causing the largest compression forces in the arch, and this method can not reflect initial geometric defects and the action of the transverse forces on it.