Budapesti Műszaki és Gazdaságtudományi EgyetemÉpítőmérnöki Kar - építőmérnök képzés 1782 óta

Masonry barrel vaults are widely applied structural members in several historic buildings like arch bridges, churches, baths etc. The in-plane behaviour of arches, as a 2D problem, is rather well explored today, but only a few studies exist about the out-of-plane effects. The aim of the proposed research is to discover the three-dimensional behaviour of barrels. Novel analysis is to be done on barrels with different bond patterns under selfweight, submitted to support displacements in longitudinal direction, and to live loads which have or do not have a longitudinal component. These tasks should be performed by taking into consideration the discrete built-up of the barrel (see below). Based on gaining a better understanding this way, strengthening techniques could be proposed. 

  

Masonry structures exhibit a complex nonlinear mechanical behaviour. The contacts between the blocks are strong for compression, but they hardly resist any tension, which introduces a non-symmetric material behaviour; in addition, the joints between blocks are often cohesionless which means they obey frictional laws. The overall structural behaviour is strongly influenced by the applied voussoir bond pattern and, in general, by the discrete built-up of the structure. Individual stones may fall out, slide along their neighbours, their contacts may partly or fully be cracked etc. Such phenomena are very difficult to be reflected with the usual continuum-based methods like Finite Element Method or Finite Difference Method. Hence different alternative, non-continuous methods (discrete element method; limit state analysis; graphostatic methods etc) are used in the engineering practice. In the proposed research such alternative methods should be applied to explore the 3D mechanics of barrel vaults and the effect of the different bond patterns. As the main outcome, suggestions should be given how to improve the performance of these structures by using either usual strengthening techniques (like tension ties, FRP strips, choice of suitable bond pattern etc) or by inventing new possibilities. 

  

The 3DEC discrete element code is available for performing the proposed research. Demonstrated previous experience in using a discrete element code with polyhedral elements is indispensable.