What type of bearing primarily allows for translational movement?

The correct answer is that a sliding plate bearing primarily allows for translational movement. This type of bearing is designed to facilitate movement along the bearing surface, enabling the structural components of a bridge or other structure to expand or contract due to thermal changes, settlements, or other dynamic forces.

Sliding plate bearings consist of a smooth, flat surface that allows for efficient movement along the plane of the bearing. This design is essential in bridge applications, as it helps accommodate horizontal movements without significant friction or wear, thus ensuring the longevity and performance of the structure.

In contrast, pot bearings and fixed bearings are designed to restrict movement in certain directions. Pot bearings, while they can allow some rotation, do not provide the same degree of translational movement and are often used to support vertical loads while accommodating some lateral movement. Fixed bearings are designed to prevent any movement at all, securing the structure in place.

Rocker bearings, while allowing for some rotational movement, do not primarily facilitate translational movement like sliding plate bearings. They are designed to support vertical loads and allow for controlled rotation as bridge components shift, but again, this is not their primary function.

Thus, sliding plate bearings are specifically constructed to accommodate translational movement, making them the most suitable choice in this context