Which joint type allows for movement in both parallel and perpendicular directions?

The type of joint that allows for movement in both parallel and perpendicular directions is the expansion joint. Expansion joints are designed to accommodate the thermal expansion and contraction of materials, as well as movements caused by other factors such as seismic activity or settlement. This capability makes them essential in bridge construction and maintenance, as they ensure that different sections of the structure can move independently without causing damage.

Expansion joints typically consist of a series of interlocking segments that can flex and slide, enabling both horizontal (parallel) and vertical (perpendicular) movements. This flexibility is critical for maintaining the integrity of the bridge and preventing stress from being transmitted to other structural components.

Other joint types, such as cellular joint seals, compression joints, and strip seals, have specific functions but are generally designed for more limited movement capabilities. For instance, cellular joint seals are primarily used for sealing against water and debris but do not facilitate significant movement. Compression joints are designed to fit tightly and limit movement, while strip seals typically offer minimal movement accommodation. Therefore, among the options provided, the expansion joint is the only one that effectively allows for both parallel and perpendicular movements.