ABSTRACT
The objectives for the geometrical correction of the Cathedral and of the adjacent Sagrario church were established on the basis of the experience previously gained while recovering the verticality of several other buildings. The need to prevent the long-term effects of regional subsidence justified the application of mortar injections. Evolution of differential settlements sustained by the Cathedral and the Sagrario up to August 2018 demonstrated that the mortar injection of the subsoil had beneficial effects on the behaviour of both churches. Settlement contours of at the level of the plane of plinths confirm that the historic settlement patterns were most favourably modified. The data and analyses demonstrate that the subsoil hardening under the churches will become an alternative that, together with other complementary actions, will help preserve these monuments. Hardening has also the advantage of being a preventive method as opposed to underexcavation that represents a corrective action.
