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结构的高阶振型对超高墩桥梁和烟囱类高耸结构的地震响应有较大影响,目前对高耸结构地震响应特性的认识还不够深入。为此,根据高耸结构简化计算模型,推导了高耸结构单阶振型贡献率和累积振型贡献率理论计算公式,并通过有限元模型进行了对比验证,研究了结构高度对结构振型贡献率的影响规律。研究结果表明:结构高度对底部剪力振型贡献率的影响最大,对底部弯矩振型贡献率的影响次之,对结构顶部位移的振型规律性影响最小。结构底部剪力和底部弯矩的第1阶振型贡献率随结构高度的增加先呈现出明显降低,后趋于稳定的变化趋势;而第2阶振型的单阶振型规律性呈现出先随墩高增加而增加,后有所降低的趋势。结构底部剪力和底部弯矩的前n阶振型累计贡献率随结构高度的增加而降低。
The high-order vibration mode of structure has a great influence on the seismic response of high-rise piers and chimney-like high-rise structures. At present, the understanding of seismic response characteristics of high-rise structures is not deep enough. Therefore, according to the simplified calculation model of high-rise structure, the theoretical formula of single-mode vibration contribution ratio and cumulative vibration contribution ratio of high-rise structure is deduced and verified by finite element model. The contribution of structure height to the contribution rate of structural vibration mode The law of influence. The results show that the height of the structure has the greatest influence on the contribution rate of the bottom shear mode, and the second one has the second largest contribution to the bottom bending mode, and the smallest impact on the regularity of the top of the structure. The contribution rate of the first mode of the bottom shear moment and the bottom moment of the structure decreases obviously with the increase of the height of the structure, and then tends to a steady trend. However, the regularity of the second order mode has the first With pier height increase and increase, after a downward trend. The cumulative contributions of the first n modes of the bottom shear moment and the bottom moment of the structure decrease with the increase of the height of the structure.