How to straighten an inclined building


25 September, 2013

How did we do it?

PREVIOUS DATA:

Ground floor building, 3 upper floors and under cover, the structure works will be based on reinforced concrete frames that receive unidirectional slabs of joists and vaults. Built in the Ponteceso wetland, the property presents a lateral collapse on its main facade of 25 centimeters from the vertical, causing a turn of the entire construction and an inclination of 2.5%, that is, 43 degrees.

The previous state before the beginning of the works: a propped up building in line with the facade pillars, which provisionally stopped the movements. Desarrolla will execute the works according to the project written by F.V.A. Architects with the assistance of Enmacosa technical consulting firm, for the design and structural calculation of the lifting process and system.

PHASE 1: Foundation consolidation

The main goal of this first phase is to consolidate the foundation of the building, not only to guarantee the correct transmission of loads to the ground, but also to constitute a firm base of work to recover the building´s verticality.

April

The demolition is carried out on the ground floor of the interior and facade partition walls. Next, the cement mortar plastering covering the pillars and the existing facilities is removed, in order to allow the free movement of the building in the phase of rectification of the collapse.

May-June

The placement of a metallic framework begins, whose function will be to support and transmit the forces between the lifting mechanism and the existing structure. For this, all the pillars are lined with steel sleeves, also placing various angles and plates. In order to obtain a better performance of the pillars, these are perforated with threaded rods taken with resin.

In the same way, the starts of the beams are also made in steel, thus creating a welded steel shell with sufficient strength to be able to proceed with the execution of the new veneers.

July

The existing screed is perforated, thus allowing the underpinning of the foundations. These elements require the execution of an excavation to the appropriate level to proceed later to the disposal of new reinforcements and their subsequent concreting. These works are affected by the rise in the tide, which limits the time available for the installation of the ironwork and concreting tasks to certain hours of the day.

The appearance of an edge beam in the foundation base, as well as the lousy state of some of the foundation slabs  further complicate the development of an already tremendously complex job.

August – September

Once all the veneers have been concreted, the concrete slab is made on the entire surface of the ground floor, to tie and center all the efforts at the base of the pillars. After said execution, the last part of the metal structure will be made, which will link these enclosures with the metal structure already made. This will facilitate and guide the block movement of the entire property.

The foundation slab will support both the hydraulic jacks and the pillars which will also be concreted, once the lifting process is finished. This base is configured as the last step to be carried out in the first phase of this project, subtracting only the proceeding to the precise and complicated challenge of raising the building.  At the base of the pillars, ball joints have been arranged that will allow the joint to be articulated.

En la base de los pilares se han dispuesto unas rótulas que permitirán la articulación del conjunto.