Engineering basics
Fixed, Guided and Free Bearings: Mapping Structural Movement Without Guesswork
A concise guide to converting movement assumptions into a consistent support-line arrangement.
6 min readFixed points are force-path decisions
A fixed bearing location transfers horizontal actions as defined by the structural design. Its position should follow the intended force path, pier and foundation capacity, expansion-joint layout and construction sequence. It should not be selected merely because a support is convenient to reach.
Guides need a declared direction
Guided bearings accommodate movement in one direction while restraining another. The guide direction must correspond to the movement vector shown on the project drawings. Curved alignments, skewed supports and staged construction can make this coordination especially important.
Free movement remains engineered
A free bearing is not an absence of design. Sliding interface, movement range, contact condition, protection, drainage and inspection requirements all influence whether the arrangement works throughout service life.
Project discussion
Need to apply this to an actual support line?
Send the bearing schedule or drawing to Andy. The review starts with your project data and the applicable requirements.