Strengthening of the Timber Roof of the Second Turkish National Assembly Building in Ankara

Toker Beeson S., Özkan Yazgan E., Ünay A. İ.

9th International Conference on Structural Analysis of Historical Constructions, Mexico City, Mexico, 14 - 17 October 2014

  • Publication Type: Conference Paper / Full Text
  • City: Mexico City
  • Country: Mexico
  • Gazi University Affiliated: Yes


The Second National Assembly Building is one of the most significant examples of the Turkish Early Republican Architecture. Originally, it was built as the headquarters for the only party of the republic; however, its function was changed shortly after construction. It served as the parliament building for 36 years from 1924 to 1961. Even though it is mostly referred to as the parliament building, the structure had more changes in function over the years. The building has been used as “The Republican Museum”. The study aims to assess the structural deficiencies in the timber roof and ceiling of the structure and explain the proposed strengthening process that is planned to start in the summer of 2014. Having been designed by Vedat Tek, who is one of the most important architects of the First National Movement, the building is among the few examples that reflect the characteristics of the period genuinely. It was constructed of masonry with two stories above the basement. The ceiling of the main meeting hall, which is 21 m x 15 m in dimensions, is supported by timber trusses at 3.5 meter intervals. The timber ceiling is unique with its historically invaluable engravings and ornamentations. However, due to the unexpected loads and material deterioration, the deflection on the ceiling exceeded 150 mm. Special work was performed on the ceiling to correct the deflection and reinforce the roof structure without disturbing the original unity of the adornments. The process involved utilizing steel trusses during restoration. The study also explores the effects of these steel trusses on the masonry arches, which support both the roof and the masonry walls of the main meeting hall. A finite element model has been prepared to explore any possible damage from steel trusses to the structural unity of stone masonry walls and arches. For the analyses, the worst possible loading conditions in strengthening process and earthquakes have been assumed. This study also covers the principles of strengthening historical buildings so as to underline the importance of conserving the original unity of paintings, engravings and other elements of ornamentation.