Removal of Deflection and Reconstruction of Foundations of the Historic Museum Building

Abstract

The displacements and forces were measured and analysed in the jacks on which the structure was rested during the complex renovation. The building was deflected from the vertical and its foundations were damaged. The renovation consisted in lifting the above-ground part of the structure and removing its deflection and then replacing the foundations. The building subject to renovation and investigations dates back to 1902; it is a historical structure and serves as a museum. The building is partially cellared, has two above-ground floors and a rectangular projection with 10.3 m and 10.7 m long sides. The building was vertically deflected by 31 mm/m. 27 hydraulic jacks were installed in order to remove the deflection in the axes of the cellar and foundation walls. With their help, the building was torn apart and then straightened by uneven lifting. After the rectification, the weight of the building was transferred onto a new system of supports transferring the load directly to the ground outside the foundations and the jacks located in the walls’ axes were dismounted. This made it possible to demolish the old stone foundations which were in very poor technical condition. New reinforced concrete strip foundations and foundation walls made of concrete blocks were made in their place. The forces and displacements in the jacks were continuously measured during the rectification. The article presents these measurements and establishes the relationships between the forces in the jacks and the displacements of the elevated building. The scope of the renovation and the innovative structural solutions applied in the construction of the foundations are also presented. The renovation of the deflected structure allowed to avoid demolition of the historic building and its re-assembly. Moreover, with the presented procedure, no damage was caused to the structure’s elements that were being lifted. The measurements of forces and displacements made it possible to determine the parameters of the straightened building.