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对某中承式钢管混凝土拱桥进行了抗震分析,拱肋按照“统一理论”换算为一种材料,首先进行模态分析,然后采用Rayleigh阻尼进行基本烈度下和罕遇地震下的时程分析。通过计算,得到了结构的固有频率、振型,不同加速度峰值下的最大内力、变形。结果表明:该拱桥平面外刚度相对较小,地震荷载下主要表现为平面外的振动和变形;拱桥在地震荷载下的受力情况复杂,必须综合考虑不同工况确定其极值内力;钢管混凝土结构的抗震性能优良,在罕遇地震下仍能保证足够的延性。
The seismic analysis of a half-through CFST arch bridge is carried out. The arch rib is converted into a material according to “unified theory ”, the modal analysis is performed first, and then Rayleigh damping is used to measure the time-history under basic intensity and rare earthquakes analysis. Through the calculation, the natural frequency and mode shape of the structure, the maximum internal force and deformation under different acceleration peaks are obtained. The results show that: the out-of-plane stiffness of the arch bridge is relatively small, and the main manifestation is the out-of-plane vibration and deformation under the earthquake load. The arch bridge under complex seismic load has to be comprehensively considered under different working conditions. The seismic performance of the structure is excellent, and sufficient ductility can still be guaranteed under rare earthquakes.