提速条件下小唐河大桥运营性能的安全性评价

针对提速后的小唐河大桥,运用动力检测方法,对其梁跨中的动挠度、横向振幅、横向及竖向加速度、振动频率,梁端横向振幅,墩顶横向振幅、加速度、振动频率,桥墩基础顶(承台顶)横向振幅等进行了测量。根据测量的结果对其进行安全性评价,评价结果表明:提速条件下各跨梁体的最大横向振幅均不满足规范的要求,墩顶、桥墩横向振幅值较大,承台顶的横向振幅也偏大,梁墩体系横向自振频率低,而各墩墩顶和梁体跨中的横向加速度值、梁体跨中竖向振动加速度值仍能满足规范的要求;梁跨具有足够的竖向刚度。根据评价的结果对小唐河大桥的加固提出了建议。

Safety Evaluation of the Xiaotanghe Bridge''''s Operative Performance under Speedup

Based on the theory of dynamic detection,the deflections,the lateral amplitudes,vertical and lateral accelerations,and the vibration frequencies at the middle point of span were measured under speedup at the Xiaotanghe Bridge.At the same time,the lateral amplitudes,the accelerations,the vibration frequencies at the top of piers,the lateral amplitudes at the pier bases were also measured.Safety evaluation was made by the results of measurement.The results of the safety evaluation show that the maximum of the lateral amplitude at every span of the bridge was not accord with the requirements of the Code for Rating Existing Railway Bridge(2004 Edition).The lateral amplitudes at the top of piers and at the pier bases all exceeded the code's limitations.The natural frequencies of the pier and the bridge span were all less than the limitation of the Code,but the lateral accelerations at the top of piers and the vertical and lateral accelerations at the middle point of span were within the range of the regulation in the Code,so the vertical rigidity of the span is enough to accord with the requirements of the Code.Accord to the results of the safety evaluation,some suggestions was provided to reinforce the Xiaotanghe bridge.