Techno Press
Techno Press

Steel and Composite Structures   Volume 24, Number 5, August10 2017, pages 549-559
DOI: http://dx.doi.org/10.12989/scs.2017.24.5.549
 
Space grid analysis method in modelling shear lag of cable-stayed bridge with corrugated steel webs
Ye Ma, Ying-Sheng Ni, Dong Xu and Jin-Kai Li

 
Abstract     [Full Text]
    As few multi-tower single-box multi-cell cable-stayed bridges with corrugated steel webs have been built, analysis is mostly achieved by combining single-girder model, beam grillage model and solid model in support of the design. However, such analysis methods usually suffer from major limitations in terms of the engineering applications: single-girder model fails to account for spatial effect such as shear lag effect of the box girder and the relevant effective girder width and eccentric load coefficient; owing to the approximation in the principle equivalence, the plane grillage model cannot accurately capture shear stress distribution and local stress state in both top and bottom flange of composite box girder; and solid model is difficult to be practically combined with the overall calculation. The usual effective width method fails to provide a uniform and accurate "effective length" (and the codes fail to provide a unified design approach at those circumstance) considering different shear lag effects resulting from dead load, prestress and cable tension in the construction. Therefore, a novel spatial grid model has been developed to account for shear lag effect. The theoretical principle of the proposed spatial grid model has been elaborated along with the relevant illustrations of modeling parameters of composite box girder with corrugated steel webs. Then typical transverse and longitudinal shear lag coefficient distribution pattern at the side-span and mid-span key cross sections have been analyzed and summarized to provide reference for similar bridges. The effectiveness and accuracy of spatial grid analysis methods has been finally validated through a practical cable-stayed bridge.
 
Key Words
    shear lag coefficient; cable-stayed bridge; spatial grid model; corrugated steel web; composite bridge girder
 
Address
(1) Ye Ma, Ying-Sheng Ni:
Research Institute of Highway Ministry of Transport, M.O.T., Beijing, 100088, P.R. China;
(2) Dong Xu:
Department of Bridge Engineering, Tongji Universtiy, Shanghai, 200092, P.R. China;
(3) Jin-Kai Li:
China Railway Engineering Design Consulting Group Co., Ltd, Beijing, 100055, P.R. China.
 

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