Abstract
This thesis concerns the modelling of three-dimensional built works in large stone course, pre-stressed or containing a large number of blocks. These structures are constructions made of stone blocks, possibly bound by joints of mortar. Their three-dimensional geometries do not generally allow the definition of a representative elementary volume. The mechanical behavior of these buildings or structures, can be studied by methods wich consider the behavior of blocks and their interactions with nearly blocks. We thus chose to model them by the Non Smooth Contact Dynamics discrete element method. The studied monuments are structures in massive stones, with simple regular course (wall) or irregular course (Julian bridge) and prestressed structures (staircase, cupola). On one hand, a new algorithm of detection of the contacts was developed to manage the planar contacts, specific in masonries. One the other hand, the computations of contact reactions often lead to a statically indefinite problem at the local level. We proposed a method of resolution which processes simultaneously all the nodes of a flat connection. The study on academic cases allowed to test the relevance of the method. A comparison was made with the method of existent resolution, implemented in the LMGC90 code.