Learning / bridge engineering
arch
Symmetric arch thrust illustration
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 curved frame with foundation stiffness, imperfections and second-order effects. The thrust line depends on loading and restraint. The arch 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
Arch ribs carry compression plus bending from asymmetric loads, geometry and support movement.
Choose a model
Use a curved frame with foundation stiffness, imperfections and second-order effects. The thrust line depends on loading and restraint.
Design considerations
Compare rise, rib section and hinge layout. Check combined compression/bending, stability, springings and erection before closure.
Durability and maintenance
Observe cracks, rib alignment and foundation movement; keep drainage away from springings.
Symmetric arch thrust illustration
A single local free-body diagram. Global load sharing, prestress, asymmetry and construction sequence are omitted.
Local equilibrium for the stated member geometry and loading; no member sizing or stability check.
Two 45° inclined legs under a crown load P: H = P/2 = 100.0 kN; each leg compression = 141.4 kN