基于DIC的预应力节段拼装桥墩变形成分分析

Deformation Component Analysis of Prestressed Segmental Bridge Piers Based on DIC

目的 研究预应力节段拼装桥墩整体变形成分及组成,为该类桥墩变形能力及抗震性能分析提供参考。方法 在拟静力试验基础上,基于数字图像相关法(DIC)对配置不锈钢和普通耗能钢筋的预应力节段拼装桥墩的变形分量进行量测计算,并分析节段拼装桥墩整体变形组成。结果 节段拼装桥墩整体变形中底接缝转动占比从最初的40%左右可达最后的85%;第二接缝也存在转动,在试验的后期占比可达到5%~10%;节段拼装桥墩弯曲变形及接缝滑移变形对墩顶位移影响随位移角增大而减小,前者占比分别从15%降至5%,后者从10%降至约5%;剪切变形对墩顶位移影响随位移角增大基本可以忽略。结论 节段拼装桥墩墩顶位移主要由接缝转动贡献,其他变形成分与接缝转动相比影响较小。

In order to provide references for the analysis of the deformation capacity and seismic performance of prestressed segmental bridge piers,the integral deformation component and the component of prestressed segmental piers was studied.Based on pseudo-static test,measured and calculated each deformation component of segmental bridge piers with stainless steel bars and ordinary steel bars by Digital Image Correlation(DIC),and analyzed the integral deformation of unbonded prestressed segmental bridge piers.The results show that the proportion of bottom joint rotation in the integral deformation of segmental bridge piers can reach from the initial 40% to the final 85%;The second joint also has rotation,finally can reach 5%~10%;The influence of bending deformation and sliding deformation on the pier top displacement decreases with the drift ratio increasing;The shear deformation on pier top displacement can be ignored with the drift ratio increasing.The pier top displacement of segmental bridge piers is mainly contributed by joint rotation,other deformation components have less effect than joint rotation.