可恢复功能的门式钢桥墩根部耗能墩柱受力机理研究

为研究新型门式钢桥墩的抗震性能,探讨了设置可更换低屈服点加劲耗能壁板的箱形钢墩柱受到反复轴向拉压作用的受力机理。采用ANSYS有限元软件,建立了设置无加劲肋和3种不同加劲肋类型的箱形钢墩柱数值模型。对比分析数值模拟结果与轴压试验测试结果,两者吻合较好,验证了有限元模型的可靠性。在此基础上,通过对比反复轴向拉压下数值分析试件的骨架曲线、位移延性系数及滞回耗能能力,探讨了低屈服点钢板的高度、宽度及厚度、加劲肋的厚度、宽度及数量等因素对箱形耗能钢墩柱受力性能的影响。研究结果表明:反复轴向拉压作用下,设置加劲肋后箱形钢墩柱的承载力增大;设置十字形加劲肋或井字形加劲肋能增大箱型钢墩柱的延性和耗能能力。

Mechanical mechanism of replaceable energy-dissipated piers at the bottom of a new type of steel portal bridge piers

In order to investigate the seismic performance of a new type of steel portal bridge piers,the mechanical mechanism of steel box piers with replaceable low yield point stiffening ribs under cyclic axial load was discussed.The finite element analysis software ANSYS was used to establish the numerical models of steel box piers with no stiffener as well as with three different types of stiffeners.The numerical results are in agreement with the axial compression experimental results,which verifies the reliability of the finite element models.Furthermore,the effects of the low yield point steel plate’s height,width and thickness and the stiffener’s thickness,width and quantity on the mechanical behaviors of steel box piers were analyzed by comparing the mechanical behaviors of the specimens in numerical analysis,such as the skeleton curves,displacement ductility coefficient and energy dissipation capacity under cyclic axial load.The results show that the load-bearing capacity of steel box piers with stiffening ribs is increased under cyclic axial load.Setting cross-shaped stiffeners or octothorpe-shaped stiffeners can increase the ductility and energy dissipation capacity of steel box piers.