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摘要: 以主梁挠度横向分布规律来确定桥梁荷载横向分布, 考虑了桥梁结构计算模态的固有频率、振型和模态质量, 提出了一种适用于各种结构形式桥梁的荷载横向分布系数计算方法, 即模态参数法。分别以一座有机玻璃模型试验桥梁和一座公路斜交T型桥梁为算例, 介绍了桥梁荷载横向分布系数的计算步骤。计算结果表明: 荷载横向分布系数的测量值与计算值最大误差为2.6%, 因此, 相比于传统的桥梁荷载横向分布系数计算方法, 模态参数法减小了对桥梁结构进行分类和假定带来的误差, 更具有通用性和准确性。Abstract: The load transversal distribution of bridge was confirmed according to the transversal distribution rule of main girder's vertical displacement. The modal parameters of bridge structure, such as natural frequency, modal shape and modal mass, were considered. A modal parameter method of calculating load transversal distribution factor was advanced for all kinds of bridge structure types. A test bridge model made of organic glass and a highway skew T bridge were selected to discuss the applying steps of the method. Computation result shows that the maximal difference between the computation value and the test value is only 2.6%, so the method for calculating the factor is more universal and exact than other traditional methods, and reduces the error resulted from the classification and assumption of bridge structures.
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表 1 跨中截面荷载横向分布系数
Table 1. Middle section's transversal distribution factors
主梁 内横梁数 文献[6] 本文方法 中梁(3#梁) 0 0.464 0.452 1 0.416 0.413 3 0.410 0.410 表 2 固有频率
Table 2. Natural frequencies
Hz 斜交角 阶次 1 2 3 4 0°(正交) 4.122 5.411 14.575 15.457 30°(斜交) 4.190 5.744 12.954 14.535 振型 对称弯曲 扭曲 反对称弯曲 扭曲 -
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