Influence of building process on stiffness: numerical analysis of a masonry vault including mortar joint shrinkage and crack re-closure effect

Behavior of masonry structures need to be characterized in order to assess masonry walls, towers and bridges. The owners of such constructions would like to understand the mechanical performance of their structures. This article presents the numerical modeling of a vault in the undamaged and damaged domains with a macro-homogenization analysis. The importance of considering the building phases in order to determine the actual stiffness of the structure is highlighted. The numerical tool is a continuous finite element model based on an original anisotropic damage model considering the masonry as a homogenized continuous medium. It computes the localized damage and indicates cracks pattern and their opening in the structure. It is able to predict the cracking zones in large masonry constructions without pre-positioning joint elements. This article focuses on the cracks induced by restrained shrinkage of the joint mortar during the building history. First, the state of the art is described and then the damage model is presented. In order to validate the model and to propose a global methodology, the damage model is applied to analyze a thin masonry vault previously tested in a laboratory. The numerical results are discussed relative to the experimental ones.