EXPERIMENTS FOR ULTIMATE LOAD-CARRYING CAPACITY OF TUBULAR ARCHES UNDER FIVE IN-PLANE SYMMETRICAL CONCENTRATED LOADS AND THE SIMPLIFIED CALCULATION METHOD

Experiments of steel tubular arch and CFST arch under five in-plane symmetrical concentrated loads were carried out. The behaviors of tube arch under multi-symmetrical loads are discussed and the simplified method to calculate the ultimate load-carrying capacity is analyzed. The analytical results show that under symmetrical in-plane multi concentrated loadings, the arch with bending moment may fail with bifurcate buckling. In the case that the axial force is dominant, the effects of filled concrete to strength and stiffness in the tubular arch are significant. The equivalent beam-column method used to calculate the ultimate load-carrying capacity of arch is stable.