中文摘要：

以宁启既有线平改立工程为实例,在现场监测数据的基础上,采用ANSYS有限元分析软件进行动力响应数值模拟,运用正交极差分析法,设计了9组模拟试验。以支墩顶部的沉降值、便梁跨中挠度的最大值及便梁跨中挠度的最大值与最小值间的差值作为支护主体稳定性的评判指标。结果表明,列车的激振频率对支护主体稳定性的影响最大,车速次之,车重的影响较小。通过分析给出了各影响因素与支护主体稳定性间的关系曲线,为既有线桥涵施工时各影响因素的合理取值指明了方向。

英文摘要：

Taking the Ningqi existing railway changed project as an example, the numerical simulation of the dynamic response are carried out by using ANSYS finite element analysis software based on measured data. 9 sets of simulation experiments are designed by using the method of orthogonal polar difference analysis. The stability of the main support is judged by the displacement of the top of piers, the maximum deflection of midspan of temporary beams and the difference Between the maximum and the minimum deflection of midspan of temporary beams. The results of these experiments in- dicate that the excited frequency of train has the greatest influence on the stability of main supporting, speed takes the second place and weight has smallest effect. The relationship curves between the various factors and stability of main sup- porting is given by analyzing the data. These curves may indicate the right direction for the reasonable values of the influ- ence factors during the bridges and culverts construction under existing railway.