With an average gradient of about 4%, the bicycle spiral bridge overcomes a level difference of 6 meters. To do so, it makes two full turns over a total length of 145 m, and the existing monumental staircase is crossed twice.

This double intersection is exactly what sets this design apart; after all, it means that much of the staircase can be preserved for pedestrians.

The foundation, structure and concrete steps of the monumental staircase have been adjusted so that the spiral can be run under the existing building. Additional foundation masses are located at the base of the steel structure.

The 3.50-meter-wide spiral consists of a self-supporting triangular tube made of painted steel with a variable thickness of 10 to 40 cm.

The two bends of the cantilever spiral on the side of the square do not rest on any intermediate support. They are 20 m long and at the lower level form a 180 ° arc (U-bend).

The safety of users, especially cyclists, is ensured by two handrails and a stainless steel net.

The floor of the spiral is covered with a durable, non-slip epoxy resin coating.

https://www.greisch.com/nl/projet/fietsspiraal-in-leuven/

http://leveninleuven.be/tags/fietsspiraal/