The upper structure of steel arch bridge is mainly composed of arch ring, suspension rod (or arch column), tie rod, bridge beam and other components.

Rigid frame arch plate is the main load-bearing structure of rigid frame arch bridge, which is generally composed of the main beam in the middle of the span, the secondary beam in the open section, the main arch leg (main diagonal brace) and the secondary arch leg (diagonal brace).

• Section form: steel box arch, steel pipe arch, steel truss arch
• Space posture: parallel arch ribs, basket arch ribs, butterfly arch ribs
• Carriageway position: upper bearing type, middle bearing type, lower bearing type
• Boom layout: parallel vertical boom, inclined boom, mesh boom

Simple system arch bridge: Only the arch ring is the main force component, with thrust directly borne by the pier or foundation.

Combined system arch bridge: Carriageway beam and arch combination, common force including tie arch, loser arch, lange arch systems.

Steel arch can be designed into truss arch, box arch, or plate arch. Truss arch bridges are particularly important for large span applications.

• Layout of arch rib truss
• Arch axis configuration
• Vector span ratio (typically 1/4~1/5)
• Height selection for vault and arch foot
• Boundary conditions
• Bar section form and area

• Pratt truss: Structural and aesthetic advantages
• Warren truss: Most economical steel usage
• K-type truss: Best mechanical properties

The main load-bearing member that primarily withstands axial pressure with some bending moment. Available in box, pipe, or truss configurations with trussed ribs offering superior span capacity and economy.

Transfer components that convey deck loads to arch ribs. Available as rigid (steel pipe/section) or flexible (high-strength wire) configurations with various elevation arrangements.

Critical for non-thrust arches, bearing the horizontal thrust through rigid or flexible configurations.

Essential for transverse stiffness and stability, available in various configurations including one-word, K-shaped, X-shaped, and meter-shaped supports.

• Strength: High strength-to-weight ratio enables long spans and heavy loads
• Ductility: Absorbs energy from dynamic loads like earthquakes
• Durability: Withstands harsh environments with proper coatings
• Flexibility: Enables curved, aesthetically pleasing designs

• Road bridges requiring long spans
• Railway bridges exceeding conventional span limits
• Highway overpasses crossing other infrastructure