Uncertainty Analysis of Reinforced Concrete Masonry Walls under Out-of-plane Loading

  • Author / Creator
    Metwally, Ziead
  • Masonry, as a conventional construction material, is widely used due to its durability, strength,
    hygrothermal performance, and aesthetics. However, the behaviour of masonry structures is not
    fully comprehended, especially in the face of uncertainty. This lack of understating on the
    behaviour of masonry structures is usually compensated by imposing overly conservative design
    provisions. Inherent uncertainties in the material and geometric properties of masonry structures
    result in large scatter in the experimentally or analytically predicted behaviour. Thus,
    understanding the influence of these uncertainties on the structural behaviour of masonry
    structures is of paramount importance to lay down the basis for reliable structural design.
    This thesis focuses on the uncertainty analysis of the out-of-plane behaviour of reinforced concrete
    masonry walls using mechanics-based finite element (FE) models and experimental testing data.
    Specifically, this thesis includes three main phases. In the first phase, the probabilistic behaviour
    of reinforced concrete masonry walls is investigated, employing mechanics-based macro FE
    models in conjunction with Monte Carlo simulations (MCS). The effect of the inherited
    uncertainties in the material and geometric properties on different response quantities (e.g., load
    capacity and deformation capacity) is also investigated through a variance-based global sensitivity
    analysis. Additionally, the model uncertainty in FE-predicted load capacity is quantified to
    characterize the model error, which is found to be influential compared to geometric and material
    uncertainties, though FE models are commonly used for numerical studies.
    The second phase focuses on assessing the reliability of reinforced concrete masonry walls loaded
    out-of-plane with the limit state functions formulated employing the developed macro FE models.
    In this phase, the importance of model uncertainty on the reliability assessment is revealed. The
    reliability assessment conducted considering different global and local failure criteria provides
    insights into their effect on the safety levels of walls. The reliability assessment is found to be
    sensitive to the adopted failure criteria. In addition, different factors are found to influence the
    reliability assessment of the walls designed according to the masonry design code; specifically,
    walls with different slenderness ratios and load eccentricities show inconsistent reliability levels.
    The model errors associated with the out-of-plane load capacity provided in masonry design codes
    in North America (i.e., CSA S304-14 and TMS 402-16) are investigated in the third phase. FEbased and experimental data are used to quantify the model error associated with design codebased models. In addition, the sensitivity of the model error to the variations associated with
    different design parameters is investigated. It is found that CSA S304-14 is overly conservative
    for highly slender walls with low load eccentricities, while TMS 402-16 gives more reasonable
    capacity predictions for such walls. However, TMS 402-16 is found to overestimate the capacities
    of highly slender walls with relatively high reinforcement ratios and load eccentricities. The codebased models are employed in reliability assessment to investigate the influence of the accuracy
    of the behavioural model on the reliability of the masonry walls. It is found that using the codebased models in the reliability assessment without considering their model error results in
    significantly biased reliability results. This highlights the need and potential room for design code
    model improvement.

  • Subjects / Keywords
  • Graduation date
    Spring 2022
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.