轨道桥梁施工过程中桩柱抗震性性能研究

Study on Seismic Performance of Pile Columns in Rail Bridge Construction Process

为了研究轨道桥梁施工过程中桩柱抗震性性能,设计了一种和原件比例是1:4的桩柱,试件通过输出力高的机械式千斤顶为桩柱施加轴向力。利用ABAQUS建立桩柱有限元模型,通过试件破坏形态、滞回性分析和骨架曲线分析结果发现,采用有限元模型对轨道桥梁施工过程中桩柱抗震性能进行研究可行。对墩柱和桩体抗震性性能研究,得出以下结论:墩柱选用0.802%纵筋配筋率时,符合抗震性能目标。在地震作用下,桩体应变与弯矩分布整体呈下小上大的趋势,接触压力整体呈两端大、中间小,同时上端明显高于下端的趋势,需重点保护桩体上端。

In order to study the seismic performance of pile columns in the course of track bridge construction,a pile column with the original proportion of 1：4 is designed,and the axial force is applied to the pile column by the mechanical jack with high output force. The finite element model of pile column is established by ABAQUS. The results of the failure form,hysteresis analysis and skeleton curve analysis show that the seismic performance of the pile column in the construction process of the track bridge can be studied by the finite element model. According to the research on the seismic performance of pier columns and piles,the following conclusions are drawn： when the 0.802% longitudinal reinforcement ratio is applied to the pier column, it meets the goal of seismic performance. Under the action of earthquake, the distribution of the strain and bending moment of the pile is larger and larger, and the contact pressure is large and small in the middle,and the upper end is obviously higher than the lower end.