Strajural, two towers at the Gateway to Asia
The Guardians of the Urals (Strajural in Russian) will shortly grow up from the ground and their silhouettes will become visible in the sky of Ekaterinburg. The project proposed by the Paris architect's office Valode & Pistre is composed of two towers that will be built at the entrance to this town marking the frontier between Europe and Asia. The 160 meter high South Tower will be entirely residential. The 180 m high North Tower that supports a 40 m telecommunication mast will contain offices and a panoramic business club. There will be a shopping centre, a cinema multiplex, a casino and restaurants open to the public, at the bottom of these two buildings. "The architects for this project have asked us to study the impact of wind on the highest of the two towers, says Julien Berthaut-Gérentes, CSTB engineer. To do this, we produced and instrumented a 1:200 scale model to measure pressures on the structure skin."
Wind from Europe, wind from Asia and Russian regulations
The wind tests were done in an "atmospheric boundary layer" wind tunnel. It was thus possible to define wind loading that could be applied to the tower as accurately as possible. The result is that the structure of the building composed of a core and external concrete walls makes it rigid enough to resist the most severe wind forces. It also satisfies all Russian regulatory standards that had to be taken into account in performing the different tests. Special attention was also paid to the antenna located on the roof, and particularly potential vibration phenomena. "We attracted the attention of designers to the potential dangers induced by the very high mast, with a cross-section that is prone to interactions with wind", says Julien Berthaut-Gérentes. Similarly, studies carried out on the comfort of pedestrians near the base of the tower suggested that wind could be particularly strong at some locations." CSTB experts made various proposals, varying from the creation of a pedestrian tunnel between the two towers to the construction of parapet walls at the top of shorter surrounding buildings, simply in order to avoid any inconvenience for persons in the neighbourhood.