In bridge construction, all horizontal forces (such as those due to wind, traffic, prestress, brake, or impact) are introduced into the adjacent structures at a fixed point. In order to avoid constraints, the remaining supports are designed as movable supports. For the movable supports, roller bearings are suitable, for example.
Possible Scheme of Bridge with Fixed and Loose Points
In the case of long continuous bridges, the horizontal forces can also be distributed over several fixed points (1 and 3). This way, you can reduce the maximum displacement distances on the moving supports (2).
