【摘要】 根据一座高强轻质混凝土连续刚构桥的结构与设计特点,对该桥的自振频率和主要振型进行了计算分析,并与同结构普通混凝土桥的动力特性加以对比,得出结论:1)高强轻质混凝土连续刚构桥基频比同结构普通混凝土桥低出13.4%;由于轻质混凝土降低了主梁的质量与刚度,导致连续刚构桥自振频率整体下降;2)轻质混凝土连续刚构桥第一振型为纵漂,与普通混凝土连续刚构桥相同,表明桥梁纵向刚度较小,柔性双薄壁墩的影响占较大比重。更多还原

【Abstract】 According to the structure and design characteristic of a prestressed high strength light-weight continuous rigid-frame bridge,a dynamic model for it was established with FEM theory.Natural frequencies and primary mode shapes of it were calculated and analyzed ,dynamical characteristic of the same structure common concrete bridge were compared with it. Conclusions are drawn as follows: 1) Fundamental frequency of the high strength light-weight concrete bridge is 13.4% lower than that of the same structure common concrete one; as a result of depressing of mass and stiffness of the girder with using of light-weight concrete, self-shake frequency of the continuous rigid frame bridge descend on the whole.2) The first mode shape of the light-weight concrete continuous rigid frame bridge is longitudinal excursion, which is the same as the common concrete bridge. It indicates that the longitudinal stiffness of the bridge is smaller than that of other direction due to great influence of the flexible double thin-walled piers.更多还原