What type of joint can consist of two steel plates sliding on top of one another with a maximum movement of 4 inches?

The type of joint that consists of two steel plates sliding on top of one another with a maximum movement of 4 inches is indeed a sliding joint. Sliding joints are designed to accommodate lateral movements, allowing two components to slide relative to one another, which is ideal for bridging gaps or transitions that may expand or contract due to temperature changes or other stress factors.

In this scenario, the fact that the joint allows for sliding motion indicates that it is capable of managing movements effectively, which is typical for bridge design where thermal expansion and contraction occur. A sliding joint specifically facilitates this kind of movement while maintaining structural integrity and safety.

Other joint types mentioned might have distinct functions or characteristics—an expansion joint, for instance, is specifically designed to allow for thermal expansion and is often more complex. An assembly joint without a seal typically does not manage movement in the same manner as a sliding joint. A fixed joint, on the other hand, does not accommodate any movement, which makes it unsuitable for applications requiring sliding motion. Understanding these functionalities helps in identifying the appropriate joint for specific circumstances in bridge designs and safety inspections.