Numerical Simulation of Dissipative Anchor Devices in Historic Masonry

Traditional cross-ties are able to restore the box-like behaviour of historic buildings, otherwise affected by the poor performance or complete lack of connections between sets of perpendicular walls. However, the localised increase of stiffness resulting from the insertion of ties in a weak substratum can cause damage such as pull-out or punching. To address this problem, the authors developed a dissipative device that is installed in series with an anchor at the joint of perpendicular walls and allows for controlled displacements, thus reducing the acceleration and the concentration of stresses in the parent material. Finite Element models of the device have been developed on the basis of experimental work. The paper focuses on the dynamic analysis performed on a half-scale model of a masonry building to assess the change in the seismic performance of the structure as consequence of the use of the dissipative devices in respect to the unreinforced and traditionally reinforced setups. Results are compared with the preliminary output of shaking table tests.