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Learning / bridge engineering

bearing slide

Friction sensitivity

Lesson review: expert verification remains open

This lesson has received a full-context editorial review and a check of its technical explanations. Selected arithmetic has been checked separately. This is not independent engineering sign-off.

Checks needed for project use

  • Bridge component studies and adjustable examples still need an independent bridge-engineering review, including applicability, load models and detailing guidance.
  • Specialist review remains for: Compare a frictionless release with a frictional contact model. A sliding guide restrains one horizontal direction and permits another; do not unintentionally fix both. The friction calculation is a local idealisation; it does not verify the displayed bridge or applicable design requirements.

These are educational models and exercises. Check their assumptions before using the results. The full technical content and every diagram have not yet been independently verified.

Concrete and steel calculations retain their stated first-generation Eurocode teaching basis. Use the standards and amendments specified for your project; do not mix generations without an appropriate design basis.

Read the lesson register and outstanding review notes

Loads and actions

Movement comes from temperature, creep, shrinkage, prestress and support displacement. Rotation accompanies flexure; the sliding element also transmits compression and friction.

Choose a model

Compare a frictionless release with a frictional contact model. A sliding guide restrains one horizontal direction and permits another; do not unintentionally fix both.

Design considerations

Choose adequate travel and overlap at both extreme positions. Detail the sliding plate, guide clearance and corrosion protection without blocking rotation.

Durability and maintenance

Dirt, damaged seals and corrosion can raise friction or obstruct travel. Compare measured position over a temperature cycle before diagnosing seizure.

Friction sensitivity

Coulomb friction sensitivity, not a certified coefficient or an actual sliding-force prediction.

With vertical reaction R = 1800 kN: horizontal friction H = μR.

H = 54.0 kN