【摘要】 采用加强固定盆式支座和墩柱强度的方法来强行保证大跨度连续梁桥在强震作用下的结构安全,固定墩会承受较大的地震力,由此导致设计的不经济性。针对上述现象,采用弹塑性减震耗能装置方案对强震区大跨连续梁桥进行减隔震设计。计算表明,通过合理设置装置的屈服力以及后屈曲刚度比,弹塑性减震耗能装置可以起到明显减小固定墩所受地震力、提高结构抗震性能的效果。对墩柱进行延性抗震设计,并分析比较不同因素对结构延性的影响。结果表明,考虑墩柱的延性可以有效降低墩柱底部弯矩。配箍率和轴压比对墩柱的延性系数影响较明显,而纵向主筋的配筋率减低,屈服和极限曲率均会降低,对延性系数的影响较小。更多还原

【Abstract】 If the fixed pot bearing and pier of long-span continuous bridge are reinforced to ensure the structure safety under strong earthquake,the bridge pier will suffer from larger seismic load,thus result in uneconomical design.Aimed at the above-mentioned problem,the elasticl-plastic isolation and energy dissipation device was proposed to do the seismic isolation design on the long-span continuous girder bridge in strong earthquake area.The calculation shows that by setting parameters about yield force and post-yielding stiffness ratio,the elastic-plastic isolation and energy dissipation device can significantly reduce seismic force exerted on the fixed pier and improve the seismic performance of the bridge structure.A ductility-based seismic design of the piers was then conducted,and a parametric study was implemented to analyze and compare the effect factor of the ductility.The results show that(1) the bending moment on the bottom of fixed pier can be greatly decreased by considering its ductility;(2)stirrup ratio and axial compression ratio have large influence on ductile coefficient;(3)cross-section yield and ultimate curvatures decrease as longitudinal reinforcement ratio decreases,and the impact of longitudinal reinforcement ratio on ductility is small.更多还原