Contents lists available at ScienceDirect Engineering Structures journal homepage: www.elsevier.com/locate/engstruct Distribution of shear force: A multi-level assessment of a cantilever RC slab Jiangpeng Shu a,b, ⁎ , Mario Plos a , Kamyab Zandi a , Altaf Ashraf a a Department of Architecture and Civil Engineering, Chalmers University of Technology, Gothenburg, Sweden b Civil and Architectural Engineering, Institute of Technology and Innovation, University of Southern Denmark, Odense, Denmark ARTICLE INFO Keywords: Load distribution Multi-level assessment Cantilever slabs FE analysis One-way shear ABSTRACT Bridge deck slabs are critical to the load-carrying capacity of bridges. The existing procedures for structural assessment often under-estimate the load capacity of bridge deck slabs and therefore further investigation is needed to check if enhanced methods are more accurate. The aim of this study was to investigate the effect of redistribution of shear forces on the load-carrying capacity of cantilever bridge deck slabs subjected to con- centrated loads. A Multi-level Assessment Strategy including analytical structural analysis methods as well as linear and non-linear FE methods was adopted. The study also aimed at understanding the effect of some geometric and support parameters on the structural response of the bridge deck slabs. The parameter study, including the influence of support stiffness, effective depth, reinforcement ratio and edge beams, helped to understand their impact on the load distribution, load-carrying capacity and failure modes. A new method for determining the effective width for one-way shear based on the nonlinear analysis and experimental evidence was proposed. 1. Introduction Bridge deck slabs are one of the most exposed bridge parts and are often critical for the load-carrying capacity. The existing procedures for structural assessment often under-estimate the capacity of existing bridge deck slabs [1]. Consequently, it is important to examine the appropriateness of current assessment and design methods and in- vestigate if advanced methods provide more accurate results. In the assessment of bridge structures, the evaluation is preferably improved successively. The assessment can generally be enhanced with respect to three different aspects, i.e. the model sophistication, in- formation of the structure as well as the uncertainty consideration. These different possibilities to improve the assessment of the existing structure are linked to each other. For example, improved information about the structure is needed to develop a more sophisticated structural model, and more advanced structural analysis requires more sophisti- cated consideration of the modelling uncertainty. In addition, a deci- sion support system is needed to determine whether and how the as- sessment should be enhanced with respect to the three aspects in a systematic way [2]; see Fig. 1. In order to provide a systematic approach for the assessment of RC slabs, Plos et al. [1] have developed a “Multi-level Assessment Strategy” which provides recommendations for the assessment of RC slabs on different levels of modelling sophistication; see Fig. 2. The strategy is based on the principle of successively improved evaluation in structural assessment. Accordingly, the assessment of the load-carrying capacity and the associated structural response can be conducted through the following levels and methods for structural analysis: (I). Simplified analysis (II). 3D linear finite element analysis (FEA) (III). 3D non-linear shell FEA (IV). 3D non-linear FEA with continuum elements and fully bonded reinforcement (V). 3D non-linear FEeA with continuum elements including the slip between reinforcement and concrete. It needs to be mentioned that the 3D non-linear FEA including the slip between reinforcement and concrete at level V are usually required when anchorage failure is included in the model. However, even in some cases of bending failure, the rotational capacity of a flexural hinge of slabs with low amounts of reinforcement can only be correctly esti- mated with a proper bond model for the reinforcement in the post-yield stage. This is critical for slabs reinforced with cold-worked steel (low ductility). The proposed strategy provides the engineering community with a framework for using successively improved structural analysis for enhanced assessment in a straight forward manner. With this strategy, case studies have shown that the analysis methods at higher https://doi.org/10.1016/j.engstruct.2019.04.045 Received 2 July 2018; Received in revised form 21 February 2019; Accepted 15 April 2019 ⁎ Corresponding author at: Civil and Architectural Engineering, Institute of Technology and Innovation, University of Southern Denmark, Odense, Denmark. E-mail address: jish@iti.sdu.dk (J. Shu). Engineering Structures 190 (2019) 345–359 0141-0296/ © 2019 Elsevier Ltd. All rights reserved. T