Construction methods · Piers, pylons and abutments

Climbing and jump formwork

Formwork that lifts itself on the pier it has just cast, anchored into the previous lift, with working platforms attached. Crane-climbed systems move with a crane; self-climbing systems use hydraulic rams and free the crane entirely. The method for tall piers and every concrete pylon.

How bridges get built · Piers, pylons and abutments · Climbing and jump formwork

Also called: jump form, self-climbing formwork, crane-climbing formwork

Concept diagram (TheBridgeEng)

How it is done

Cast the first lifts conventionally; install the climbing brackets and platforms.
Cycle: fix reinforcement, close the forms, pour 4-5 m, strip, climb (crane or hydraulic), repeat every 4-7 days.
Adjust the form geometry as the pylon tapers or inclines; survey every lift for verticality and twist.

Where it fits

Piers over 25 m, valley viaducts, concrete pylons of 60-300 m, inclined pylon legs (with tie-backs during construction).

Where it does not

Short piers, where the setup costs more than it saves.

Plant, pace and money

PlantClimbing system (Doka, Peri or similar), tower crane or self-climbing hydraulics, concrete pump with placing boom.

ProductivityOne 4-5 m lift per 4-7 days per leg; a 150 m pylon in 8-12 months.

CostUSD 600-1,200 per m3 of pylon concrete including the system.

Risks and controls

What goes wrong

Anchor failure during climbing, wind on platforms, geometry drift accumulating over the height, cable anchorage zones with congested reinforcement.

Quality assurance

Survey of every lift (verticality within height/1,000 or better), anchor cone tests, reinforcement cover checks, temperature control in thick sections.

Examples

Millau (245 m piers), Sutong and Russky pylons, Incheon Bridge pylons; the game's pylon duration is based on lift cycles.