对大跨度钢管混凝土拱桥在三维地震激励下进行了非线性时程分析。几何非线性分析采用修正拉格朗日描述(U.L列式法),材料非线性采用钢管混凝土统一理论并考虑等效紧箍力,通过对某大跨度钢管混凝土拱桥的非线性地震响应分析,研究了几何非线性、材料非线性、阻尼比及行波效应对拱桥地震响应的影响。结果表明:几何非线性对钢管混凝土拱桥地震响应的影响程度与结构的地震响应幅度有关;阻尼比和行波效应对钢管混凝土拱桥地震响应的影响是显著的;材料非线性对拱肋位移和轴力的影响较小,但对拱肋的面内外弯矩影响较大。
The nonlinear time-history of long-span concrete filled steel tubular(CFST) arch bridge under 3D earthquake excitations was analysed.The geometrical non-linearity was analysed with updated Lagrange formulation,and the material non-linearity was analyzed by the unified theory and equivalent confined stress.The influence of geometrical non-linearity,material non-linearity,damping ratio and traveling wave effect on the earthquake response of the bridge was studied based on nonlinear seismic response analysis of a long-span CFST arch bridge.The results show that(1) the influence of geometrical non-linearity on the seismic response of CFST arch bridge is concerned with the seismic response amplitude of structure;(2) the influence of damping ratio and traveling wave effect on the seismic response of CFST arch bridge is remarkable;(3) the material non-linearity has little effect on the displacement of arch rib and axial force,but has great effect on the in-plane and out-of-plane bending moment.