Shear lag effect of composite girders in cable-stayed bridges under dead loads. (15th April 2023)

• Record Type: Journal Article
• Authors: Wang, Chun-Sheng; Zhang, Wen-Ting; Yang, Meng-Yi
• Is Part Of: Engineering structures. Volume 281(2023)
• Publication Date: 2023-04-15
• Subjects: Cable-stayed bridge -- Composite girder -- Shear lag effect -- Effective slab width -- In-situ test -- Dead load -- Stress ratio; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2023.115752
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: In-situ tests for shear lag effect analysis of a composite cable-stayed bridge at the construction and service stages are carried out. The stress ratio is the main factor affecting the shear lag distribution by internal force analysis. A theoretical method considering additional deflection was proposed and calibrated with test and FEM results. Slab widths and cable spacings are the key parameters affecting the shear lag by full-scale parametric analysis. Designers should focus on the shear lag effect in mid-span, near tower, and cable anchorage sections of cable-stayed bridges. Abstract: The shear lag effect is a common phenomenon among civil infrastructures, which is also a critical issue for composite girders. For composite girders in large-span cable-stayed bridges, there is a large proportion of internal forces caused by dead loads, and the shear lag effect of the concrete slab under dead loads is significant. To investigate the normal stress distribution at the construction and service stages, systematic in-situ stress monitoring of composite girders was performed on a cable-stayed bridge under dead loads. Then, the finite element models were built for numerical modeling. The theoretical analysis model was proposed to evaluate the shear lag effect of composite cable-stayed bridges under dead load. Then the law of the stress ratio and the shear lag effect was analyzed by contrasting the test data and simulation results. Meanwhile, the calibrated FE models were used to do the full-scale parametric analysis of the factors including span length, slab width, and cable spacing. The results show that the main girder segment near the bridge tower and the mid-span are critical sections at the construction and service stages for analyzing the shear lag effect. The cable spacing and slab width are the main factors affecting the shear lag effect under dead loads. The effective width coefficients are positively correlated with the stress ratio.