The first stage of reconstruction
The reconstruction of the City Hall was done in several stages, as the renovation process was conditioned by the technical and financial assumptions that had to be fulfilled with the coordination of the investor, technical teams and all structures involved in the reconstruction.
THE FIRST STAGE OF RECONSTRUCTION
In 1996, the Government of the Republic of Austria donated DM 1.500,000 for initial works on the reconstruction of the City Hall in Sarajevo. The money should have been realized for the most subtle works that were to save the structure that survived. Apart from the destruction of the war, the City Hall permanently continued to perish as the four winters of war contributed to the further destruction of the opaque walls of the attic, the hallway, the steel construction of the dome, and especially the walls of the ground floor, which continually pumped water out of the huge amount of ruined and decomposed material found on the ground floor (average height of 1.00-1.50 m).
Until then, only preliminary studies of the state of the construction were carried out by Ser.Co.Tec. from Trieste, which included only a part of research on available constructions. By analyzing the original structure of the building (supporting open walls and steel supports as a structure that has overcome all the essential ranges, as well as the steel construction of the dome and the lowered ceiling as the overall construction concept of the building), it was decided to use the same constructive system in the process of reconstruction, and solutions are defined by satisfying the primary task of rescuing the object through the following phases:
A - stabilization of constructive masonry structures,
B - reconstruction of roofs with the execution of a lightning rod installation,
C - renovation of a steel dome and a lowered ceiling with restoration of a glass cover,
D - Acceptance of heavily damaged construction by massive supporting scaffolding.
A - At the level of ceiling wooden structures, steel brackets at a distance of 3.50 - 3.80m were connected by steel diagonal, creating horizontal hinges which at this stage should create conditions for the renovation of the ceiling walls and the reconstruction of the roof.
B - According to the available architectural documentation, all wooden roofs with light bulb installation are designed and executed. Most of the opaque structures of the ceilings were renovated as part of the original chimneys. The original drainage system of rainwater was installed, through open roof channels that were accepted in three existing verticals.
C - The review of the steel structure and the results of the steel structure of the City Hall found that steel is of satisfactory quality construction, because the cross sections are well dimensioned. The overall structure is attacked by the corrosion process. About 20% of the structure was deformed by fire and certain parts had lost their static geometry. All the damaged parts were replaced, the connections were made through the rivet as in the original construction, and the overall structure with the sandblasted ceiling up to Sa 2,5 and anticorrosive in four layers of 120 microns thick. Armored glass as a cover has been updated with the use of special holders that prevent slipping, as it happened before. The corners on the upright towers and the central dome are designed and constructed.
D-Reactioned steel construction and lowered ceilings, on one side, rely on the edging walls and the structure of the classroom which is part of the structure that has suffered the greatest damage. A heavy steel carrying deck with special massive wooden straps was designed and constructed, making the classroom design acceptable. This performance prevented damage to the dome-made work and also created the conditions for restoring the structure of the classroom.
The works were designed and executed in 1996 and 1997. The facility is temporarily covered and closed by weather influences. As the moisture was prevented, the drying of the entire object was gradually dried and conditions for further investigations were created.
Investor: Republic of Austria
Design: d.D.Dom Studije, projektovanje, inženjering – Sarajevo
Builder: ŽGP Sarajevo
Supervision: WCI (Austrija) and Zavod za izgradnju Kantona Sarajevo