钢管混凝土压弯拱非线性临界荷载计算的等效梁柱法

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

对于截面上同时存在轴力与弯矩共同作用的抛物线钢管混凝土压弯拱的失稳临界荷载,采用截面内力的相关方程进行了等效梁柱法的计算;对于相关方程中的稳定系数,采用了考虑矢跨比因素的系数K1和初始缺陷因素的系数K2的乘积形式来表达;对采用不同钢管混凝土结构理论体系中的相关方程进行拱的非线性失稳临界荷载计算进行了讨论。通过与试验结果和有限元结果的对比表明,该文所提出的等效梁柱法能方便且较精确地计算抛物线压弯钢管混凝土拱的极限承载力。

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.