Intermediate Steel Arch Bridge Architect Economical CNAS Certificate

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. The bridge deck spans across the arch and carries the load of vehicles, pedestrians, and other loadings.

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

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 work in combination to share forces.

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

Key design parameters for long-span steel truss arch bridges include:

• Arch rib truss layout
• Arch axis configuration
• Vector span ratio
• Vault and arch foot height selection
• Boundary conditions
• Bar section form and area

The main load-bearing member that primarily withstands axial pressure with some bending moment. Available in box, pipe, or truss type sections.

Force transfer component that transmits deck load to arch ribs. Available as rigid (steel pipe/section) or flexible (high-strength wire) configurations.

Bears the thrust of non-thrust arches through axial tension. Available in rigid or flexible configurations.

Ensures transverse stiffness and stability while withstanding horizontal forces. Common configurations include one-word, K-shaped, X-shaped, and meter-shaped braces.

• Rise span ratio: Typically 1/4~1/5 for steel truss arches
• Arch rib height: Equal height or variable height configurations
• Arch axis: Arc line, quadratic parabola, or catenary forms