Learning / bridge engineering
rail
Fully restrained rail temperature stress
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: Use a beam on elastic support for vertical behaviour and a longitudinal rail–fastener–deck model for interaction. Nonlinear resistance differs between unloaded and loaded track. The rail 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 notesLoads and actions
Rails bend locally under wheel loads and carry longitudinal forces from temperature, traction, braking and deck interaction. The continuous rail extends beyond the bridge.
Choose a model
Use a beam on elastic support for vertical behaviour and a longitudinal rail–fastener–deck model for interaction. Nonlinear resistance differs between unloaded and loaded track.
Design considerations
Check rail stress, end movement, deck rotation and track stability with the applicable railway criteria. Rail expansion devices are a system decision, not an automatic cure for a long deck.
Durability and maintenance
Track geometry, fastening condition, ballast restraint and rail defects all affect the assumed interaction. Maintain records of rail stress-free temperature where required.
Fully restrained rail temperature stress
Fully restrained bar bound only; does not solve rail–bridge interaction or establish a permissible additional rail stress.
Assume E = 210 GPa, α = 12×10⁻⁶/°C: σ = −EαΔT (compression on heating).
Rail stress = -75.6 MPa