Requalification des ouvrages anciens

ABSTRACT The aim of this research is to built an assessment method for masonry arch bridges by modelling and computing. The method was developed and tried on a vault build in 1870 in south-west of France. It is made of three steps. The first one is an historic research. It is necessary to know the exact bridge constitution (geometry, materials, construction process). The second step is an experimental approach whose aim is to establish the homogenized masonries mechanic behaviour law and an interface law between homogenized blocks and including the mortar tensile and shear behaviour. The third step is the 3D computing of the bridge, using a finite element method. The specificity of the model is to take into account the interface law using “joint elements” and the homogenized behaviour law of blocks as a constitutive law of finite elements. A parametric study has established the factors involved in the bridge security.