Citadella – A szabadság bástyája

Project name: Citadel project – „Bastion of freedom”
Project address: Citadella, Budapest
Project type: Historical monument complete reconstruction
Year of construction: 1854
World Heritage status: UNESCO – 1987
Project size: 10.850 m2

General designer: art1st design studio Kft.
General structural designer: ARC-S Group Kft.

The building:
The Citadel, located in the 11th district of Budapest on the top of Gellért-hill, built by the Habsburg emperor in 1854 after repressing the Revolution and War of Independence in 1848-49. The Buda Castle Hill with the two riverbanks panorama of the Danube including the Gellért Hill and the Citadel received World Heritage status by the UNESCO in 1987.

The main goal of the complete reconstruction works is to give proper honour to one of the most prestigious Hungarian touristic attraction by transforming the original fortress function to a community space and save it from destruction. To achieve this goal considerable amount of changes are necessary in the existing building by demolishing old parts and rebuilding new parts.

Describing the structure:
The existing building structure is approximately 220 m long and has a wall height of 12-16 m. It is entirely masonry construction, with an average 1.5 m thick mixed masonry for the vertical supporting structures and a three to five row of brick dome structure for the horizontal boundary structures.
The rebuild will involve significant cuts in the existing structure in several places.
New features will be created by replacing the demolished parts of the building and by using different structural materials within the building. In addition to the commonly used monolithic reinforced concrete and steel structures, we will use precast white reinforced concrete, multi-layered bonded glass as the primary load-bearing structure (glass column, beam, slab, bridge), coupled with stainless steel, and topped with insulated glazing. In addition, the restoration of masonry structures that have been destroyed over time is required in several places.

TEKLA modelling:
The building of the model started by capturing the existing condition and then splitting it into existing-remaining and existing-demolition structures. An important consideration in the design of the demolition-construction models was to ensure that they were phased due to the short construction timeframe.
Due to the diversity of the structure, a multi-material model was developed, in which different materials and material properties were separated taking into account their own specifications (attributes). The complete model ultimately includes monolithic reinforced concrete, precast reinforced concrete, carbon steel, stainless steel, aluminium, masonry and glass structural materials.
The structural elements are included in as much detail as possible, so that the monolithic reinforced concrete structures include all the rebars to be installed, and the precast structures including all the additional elements, layers, adhesives and fasteners required for installation.

The detailed modelling, the Trimble XR10 device and the HoloLens 2 subscription available to us provide the opportunity for innovative presentation of the designed structure, modern monitoring and full control of the construction, the testing and more detailed development of which within our company is taking place in parallel with the implementation of the project.

The demolition and construction works are currently in progress.
As an existing building, part of which is to be preserved and part of which is to be demolished, the model is still evolving. As unexpected structural problems and discrepancies arise during the construction process, the structural model is constantly changing and refining until the designed conversion is completed.

Participated in the design:

Evelyn PAP
Dezső ÁGOSTON
Boldizsár BÁRCZI
Raymond BÜKKÖSI
Péter DAMÁZSDI
Csaba JANDEK
András LATOROVSZKY
Attila MÁRTA