钢管混凝土格构式梁桥设计参数抗震研究

Research on seismic applicability of design parameters of continuous bridges with concrete-filled steel-tube latticed high-rise piers

以三跨一联钢管混凝土格构式高墩连续梁桥为研究对象,探讨了梁墩刚度比、缀管布置形式和有无减隔震装置设计参数对格构墩地震响应(墩底轴力、墩底弯矩和墩顶位移)的影响规律。研究结果表明:随着梁墩刚度比值的增大,桥墩的地震响应值先急剧下降之后逐渐趋于平缓减小;缀管布置形式参数对格构墩的弯矩响应值影响较为敏感,而轴力和位移值受其影响较小;减隔震装置对该类桥梁的隔震效果显著,隔震率随梁墩刚度比值的增大而减小。设防烈度等级越高,轴力隔震效果越明显,弯矩和位移的隔震率受设防烈度等级影响较小。该研究可为同类桥梁抗震概念设计提供借鉴与参考。

Three-span continuous bridges with concrete-filled steel-tube latticed high-rise piers were studied with a discussion of the girder-pier stiffness ratio, tube arrangement types and the influence of design parameters of seismic isolation devices on seismic response of latticed piers （ on pier bot- tom＇ s axial force and its bending moment and pier top＇ s displacement）. Results show that with the increase of the girder-pier stiffness ratio, the seismic response value of the pier gradually decreases after a sharp decrease. The bending moment response value of latticed piers is more sensitive to the parameters of the tube arrangement than the axial force and the displacement value, which are almost unaffected. And the effect of the seismic-isolation device is especially remarkable with the re- sponse value decreasing as the girder-pier stiffness ratio increases. As for the seismic precautionary intensity grade, the higher it is, the more obvious the seismic-isolation effect of the axial force is, while the seismic-isolation ratios of the bending moment and the displacement are less affected. The study may serve to provide reference for seismic designs of similar bridges.