波纹钢腹板连续刚构桥抗震性能研究

Research on Seismic Performance of Continuous Rigid-frame Bridge with Corrugated Steel Webs

根据箱梁截面抗剪能力相等原则,建立了波纹钢腹板连续刚构桥和相应的混凝土腹板连续刚构桥有限元模型,对二者的动力特性和抗震性能进行了对比分析。结果表明:混凝土腹板刚构桥的竖向1阶频率、纵向1阶频率均高于波纹钢腹板刚构桥,横向1阶频率相差不大。无论在横桥向还是纵桥向,梁体质量的减小均使得梁体的地震作用减小。在横向地震作用下,波纹钢腹板刚构桥矮墩的内力、高墩墩顶剪力均小于混凝土腹板刚构桥,而高墩墩顶弯矩、墩底内力均大于后者;在纵向地震作用下,波纹钢腹板刚构桥矮墩及高墩墩顶内力均小于混凝土腹板刚构桥,而高墩墩底的内力大于后者,所以在设计中应对非规则桥型布置方案中的高墩引起足够重视。

The FEA model of continuous rigid-frame bridge with corrugated steel webs and the corresponding continuous rigid-frame bridge with concrete webs are established with design principle of equivalent shear capacity of box girder section. The dynamic characteristics and seismic performance of the two models are analyzed and compared. The result shows that the first vertical and longitudinal frequencies of rigid-frame bridge with concrete webs are higher than rigid-frame bridge with corrugated steel webs, while the first transverse frequency has little difference. No matter in longitudinal or transverse direction, the decrease of girders＇ weight can alleviate earthquake action. Under the transverse earthquake action, as to the continuous rigid-frame bridge with corrugated steel webs, the internal force of the lower pier and shear force on the top of the higher pier are smaller than continuous rigid-frame bridge with concrete webs, while bending moment on top of the higher pier and the internal force on bottom of the higher pier are greater. Under the longitudinal earthquake action, as to the continuous rigid-frame bridge with corrugated steel webs, the internal force of the lower pier and top of the higher pier are smaller than that with concrete webs, but internal force on bottom of the higher pier is greater. So it should be pay enough attention to the high pier for the irregular bridge plan in designs.