EQUIVALENT BEAM-COLUMN METHOD TO CALCULATE NONLINEAR CRITICAL LOAD FOR CFST ARCH UNDER COMPRESSION AND BENDING

In order to calculate the critical load of parabolic concrete filled steel tubular (CFST) arch under compression and bending, the equivalent beam-column method was adopted by introducing a correlation equation of inner forces. The buckling factor in the correlation equation was the product of K1 which reflects the effect of span to rise ratio and K2 which considers the effect of initial geometric imperfection. The nonlinear critical loads of CFST arch were calculated by different methods and discussed. A comparison with the test results and FEM results indicated that the critical load of parabolic CFST arch under compression and bending could be calculated accurately by the presented equivalent beam-column method.