Modelling tunnelling-induced settlement of masonry buildings

Current practice for assessment of settlement damage to buildings due to tunnel construction usually starts with a procedure in which greenfield settlements are imposed on a structual model of the building. This process ignores the important interaction effects that the weight and stiffness of the building have on the settlements. This paper describes a three-dimensional finite element analysis in which the tunnel, the soil and a building are all treated in a single analysis. Example calculations are described, and these indicate that interaction between the building and the ground can have a significant effect on the extent of the predicted damage. The performance of the building is seen to be highly dependent on whether the settlements induce a sagging or hogging mode of deformation. The analyses are used to plot contours of soil surface settlement and also expected crack patterns within the building.