水平双向地震作用下薄壁方形截面钢桥墩抗震性能试验及实用算法研究  

Seismic performance test and practical calculation method of thin-walled square-section steel piers under horizontal bi-directional seismic excitations

作　　者：诸葛翰卿 谢旭[1] 李帅领 王建东[2] Zhuge Hanqing;Xie Xu;Li Shuailing;Wang Jiandong(Zhejiang University,Hangzhou 310058,China;Zhejiang University of Technology,Hangzhou 310023,China)

机构地区：[1]浙江大学,浙江杭州310058 [2]浙江工业大学,浙江杭州310023

出　　处：《土木工程学报》2020年第12期74-85,共12页China Civil Engineering Journal

基　　金：国家自然科学基金面上项目(51878606)。

摘　　要：钢板局部失稳破坏是钢桥墩结构典型的地震失效模式之一,但目前仍缺乏既能考虑局部失稳影响,又可方便用于工程设计的结构地震反应计算方法。通过对2个薄壁方形截面钢桥墩试件施加沿斜向的水平反复荷载,研究结构的地震破坏形式和抗震性能;在钢材修正双曲面滞回模型的基础上,通过对结构参数分析结果的数据拟合,建立考虑钢板局部失稳影响的方形截面钢桥墩纤维模型算法。结果表明:薄壁方形截面钢桥墩结构在水平双向地震作用下,首先会发生墩底钢板局部失稳,在荷载达到最高点后墩底焊缝处出现超低周疲劳破坏,在两种地震破坏的共同作用下结构承载力迅速下降;通过与试验结果的对比,验证结构地震有效损伤域L_d内的纤维单元采用等效滞回模型能准确反映钢板的局部失稳效应,为工程设计提供一种高精度的实用计算方法。Local instability of steel plates is one of the typical seismic failures of steel pier structures.However,there is still a lack of structural seismic response analysis methods that can take into account the effect of local instability and be conveniently used in the engineering design.By applying horizontal cyclic load in oblique direction to two thin-walled square-section steel pier specimens,seismic damage form and seismic performance of structures were studied.Based on the modified two-surface steel hysteresis model,a fiber-model calculation method considering the effect of local instability of steel plates of square-section steel piers was established through data fitting of the structural parameter analysis results.The results show that under bi-directional seismic excitations,thin-walled square-section steel pier structures will firstly suffer from local instability of steel plates at the bottom of piers,and ultra-low-cycle fatigue cracking will occur at the weld of the bottom after the load reaches the highest point.Under the combined action of two types of seismic damage,the bearing capacity of the structures drops rapidly.By comparing the analysis results with the test ones,it is shown that if the equivalent hysteresis model is adopted for the fiber elements in the effective damaged zone Ld of structures,the local instability effect of steel plates can be accurately considered.The research results can provide a high-precision practical calculation method for engineering design.

关 键 词：桥梁工程 薄壁方形截面钢桥墩 水平双向地震作用 拟静力试验 局部失稳 纤维模型 

分 类 号：U448[建筑科学—桥梁与隧道工程]