摘要
In steel-concrete composite twin-girder decks, wide concrete slab would undergo significant shear lag warping effect, including positive and negative. Some researchers have investigated the positive shear lag of composite decks by means of one-dimensional line model, while the studies on the negative shear lag have not yet been reported until now. In this study, a new one-dimensional analytical model of composite twin-girder decks is first proposed based on the model proposed by Dezi et al. Besides slab shear lag effect and partial connection at slab-girder interface which have been included in the model of Dezi et al., the particularity of the proposed model relies on its ability to account for variation characteristic of cross-section. Verification of the analytical model is later conducted through comparison of results from the analytical analysis and elaborate FE analysis for a simply supported composite deck with increasing depth and a two-span continuous one with decreasing depth. Finally, three kinds of structural forms of composite twin-girder decks, including cantilever, simply supported and continuous decks, are selected to carry out the analysis of positive and negative shear lag behaviors by means of the analytical model. The influences of cross-sectional variation characteristic and load type on positive and negative shear lag behaviors are mainly investigated. Additionally, a new definition on effective width for considering simultaneously positive and negative shear lag behaviors is proposed. The results from the proposed analytical model and EC4 specification are compared to provide suggestions for designers and checkers. In this study, the proposed analytical model can provide a powerful numerical tool for researchers to conduct the further investigation, and the analysis on shear lag and effective width can assist in design analysis of composite twin-girder decks.
In steel-concrete composite twin-girder decks, wide concrete slab would undergo significant shear lag warping effect, includ- ing positive and negative. Some researchers have investigated the positive shear lag of composite decks by means of one-dimensional line model, while the studies on the negative shear lag have not yet been reported until now. In this study, a new one-dimensional analytical model of composite twin-girder decks is first proposed based on the model proposed by Dezi et al. Besides slab shear lag effect and partial connection at slab-girder interface which have been included in the model of De- zi et al., the particularity of the proposed model relies on its ability to account for variation characteristic of cross-section. Ver- ification of the analytical model is later conducted through comparison of results from the analytical analysis and elaborate FE analysis for a simply supported composite deck with increasing depth and a two-span continuous one with decreasing depth. Finally, three kinds of structural forms of composite twin-girder decks, including cantilever, simply supported and continuous decks, are selected to carry out the analysis of positive and negative shear lag behaviors by means of the analytical model. The influences of cross-sectional variation characteristic and load type on positive and negative shear lag behaviors are mainly in- vestigated. Additionally, a new definition on effective width for considering simultaneously positive and negative shear lag behaviors is proposed. The results from the proposed analytical model and EC4 specification are compared to provide sugges- tions for designers and checkers. In this study, the proposed analytical model can provide a powerful numerical tool for re- searchers to conduct the further investigation, and the analysis on shear lag and effective width can assist in design analysis of composite twin-girder decks.
作者
ZHU Li
NIE JianGuo
JI WenYu
ZHU Li NIE JianGuo JI WenYu(School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Department of Civil Engineering, Tsinghua University, Beijing 100084, China)
基金
supported by the Fundamental Research Fund for the Central Universities(Grant No.2015JBM069)
the Research Fund for Talented Scholars of Beijing Jiaotong University(Grant No.2016RC026)
关键词
钢水泥合成双胞胎系结甲板
分析模型
剖面图的变化
积极、否定砍落后行为
有效宽度
steel-concrete composite twin-girder deck, analytical model, variation of cross-section, positive and negative shear lagbehavior, effective width
