The transverse stiffness of medium-span railway bridge becomes insufficient and its transverse vibration becomes larger commonly under the raised speed freight train.

中等跨度铁路桥梁在提速货车作用下，普遍出现横向刚度不足，横向振动超限问题，严重影响了运营安全和提速计划的顺利实施。

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The first frequency method of estimating the fatigue serviceability on small and medium span railway concrete bridge is discussed in this paper through three piece test beam under fatigue load.

通过三片模拟梁试验实测结果，探讨了基频法评估铁路桥梁疲劳使用性能的可行性。

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Now this type of bridge is applied to more and more medium and small-span Bridges in cities, even large-span Bridges over rives.

目前在我国，越来越多的城市中小型桥梁，乃至跨江河的大桥都采用这种桥型方案。

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