Problems of Tensioning Bracing Elements for the Roof Structure Assemblage

Nicolae SOCACIU

Lecturer

Technical University Cluj-Napoca, Romania

Radu ZOICAS Prep.Ph.D. Student Technical University Cluj-Napoca, Romania zoicasradu@yahoo.com

Tudor PETRINA

Assistent

Technical University Cluj-Napoca, Romania

Tudor.Petrina@mecon.utcluj.ro

Monica NICOREAC Ph.D. Student Technical University Cluj-Napoca, Romania

Monica.Nicoreac@mecon.utcluj.ro

This paper presents the bracing possibilities for the metal structure of the Municipal stadium roof of Cluj-Napoca. The main structure of the roof is made of cantilever trusses with an opening of 15-33 m, supported by the concrete structure of the stands through base plate and bolts embedded in concrete connections. In the longitudinal direction there are purlin trusses with opening between 8- 10m. In order for the structure to have spatial stability, bracing systems were provided in both the canopy plane and between the structure’s elements. This system has compression elements made of pipes and tension elements made of bars. The latter elements are fitted with threaded collars for initial pretensioning. The paper aims to study the effect that the pretensioning stresses in the bracing elements have on the spatial behaviour. Taking into account that the wind acts simultaneously from above and below, the stability of the upper flange and lower flange must be provided for. After analysing a number of bracing solutions, the optimum one is chosen taking in consideration the minimum material needed.