Lisboa, Portugal

New Cycling and Pedestrian Bridge over the 2ª Circular in Lisbon

Impromptu arquitectos, Selahattin Tüysüz Architecture

Images: Impromptu Architects + Selahattin Tuysuz Architecture

The proposed design intends to be an iconic landmark flying delicately over the busy road of “2ª Circular”. Based in the shape of number “eight”, with an unsymmetrical arrangement, it combines in a single and continuous object the three main components of the bridge: the deck, the two access ramps and a suspension arch. The bridge geometry generates a dynamic visual experience, since it offers a rich diversity of forms varying according from where it is approach, both for the pedestrians and cyclists as well as the drivers passing under.

Images: Impromptu Architects + Selahattin Tuysuz Architecture

The bridge is structurally based on a deck supported by an arch. Besides the forces from the structural behavior in the vertical plan, the geometry of the bridge induces torsions and biaxial bending in the section. Due to the type of efforts (biaxial bending with torsion) it is foreseen in the arch a steel box section and in the deck a similar box section with the top flange constituted by a composite floor-slab providing the basis for the pavement.

Images: Impromptu Architects + Selahattin Tuysuz Architecture

The selection of bridge materials is based on durability and low maintenance. The structure is made out of steel and over the bridge deck it is used a layer of slurry pavement, that should be identical to the cycle paths, in order to emphasize the continuity of the paths through the bridge. The parapets are made of thin stainless steel extruded profiles, spaced with 170mm and capped by a stainless steel top rail.

Images: Impromptu Architects + Selahattin Tuysuz Architecture

The design comprises a sustainable lighting system. It is used light sources of low energy consumption, such as LED’s, o produce a diffuse and uniform light on the underside of the bridge deck and arch, in order to emphasize its geometry, without causing light pollution or dazzling the road users. For the pedestrian route, the lighting will be punctual and in accordance with the parapets creating a guideline for its users. The lighting scheme is powered by a photovoltaic system integrated in the upper surface of the arch, with a south orientation.