Collapse Prevention Works for Voyiatzidis Mansion in Andros Town

Project description

Client: Voyiatzidis
Location: Andros Town
Year: 2017

The building owned by L. Voyiatzidis in Andros Town, was characterized as work of art and listed monument, based on a ministerial decree of the Ministry of Culture in 1991. Its construction was completed in 1917. In 2016 the structural integrity of the structure was characterized as very poor by the Urban Planning Service of Andros. The main structural elements (masonry walls, wooden floors, roof) had major damages. The most severe damage was the detachment of the western and the southern perimeter masonry walls at the floor level (inclination of 5%, 20cm from the vertical plane) with risk to fail out of plane and cause the structure to partial collapse. ENKA was asked to design and execute immediate collapse prevention works at the building by restraining the masonry perimeter walls.

Tasks description

After the removal of the semi-destroyed wooden roof and the installation of temporary working platforms, post-tensioning wire ropes were installed to temporarily tie the detached walls. Reinforced concrete wall ties (chainage) were constructed on top of the interior walls. Temporary tie rods, tightened on the chainage, were used to pull back the exterior masonry walls via controlled force exertion with torque wrench. After the restoration of the walls, steel nail anchors were installed on the corners of the walls throughout the full height of the building. Grout injections were applied on the masonry walls and the temporary tie rods were substituted by permanent ones.

The process for restoring the walls back into the vertical planes was carried out gradually while monitoring the behavior of the walls for any potential failure. The verticality of the detached walls was restored in a percentage > 90%.