Passive control of bridges: The double cable net method

We propose a new type of cable-supported bridge. The main elements of the bridge are two cable systems, (α) and (β), and a concrete bridge deck. The combination of a deck structure and a net of external prestressed cables is a very advantageous structural system because the use of external prestressing cables, called (a), neutralizes the permanent load and some of the moving loads. However, the rest of the moving load's action on the cables often causes large displacements, which are not compatible with the deck structure being connected. A successful method for minimizing the aforementioned undesirable displacements is using a passive control system based on the application of a second group of cables, called here a cable (β) net. The passive control system is used to absorb the traffic loading, as well as the wind and the earthquake action.