Construction methods · Heavy lift, moving and accelerated construction

Lateral slide (slide-in bridge construction)

The new bridge is built beside the existing one on temporary supports, the old bridge is demolished in a short closure, and the new one is slid sideways onto the permanent supports on PTFE pads with jacks. Traffic loses a weekend instead of a year.

How bridges get built · Heavy lift, moving and accelerated construction · Lateral slide (slide-in bridge construction)

Also called: slide-in, lateral launching, bridge slide, SIBC

slide track (PTFE)new bridge built beside the roadslid sideways in a weekendtemporary supports, then jacks push the deck onto the bearingsLateral slide
Concept diagram (TheBridgeEng)

How it is done

  1. Build the new superstructure on temporary piers or a falsework alongside, complete with deck, parapets and surfacing.
  2. Prepare the permanent piers with slide tracks; demolish or remove the old bridge in the closure.
  3. Push or pull the new bridge with hydraulic jacks or strand jacks at 1-3 m per hour over 1-3 spans width; land on the bearings; open to traffic.
  4. Remove the temporary works.

Where it fits

  • Replacements of bridges over live roads, railways and rivers; spans 30-120 m; single or multi-span decks built at the final level.

Where it does not

  • Sites without room beside the alignment; decks too flexible to slide without distortion; skewed slides without engineering.

Plant, pace and money

PlantTemporary supports, slide tracks and PTFE, jacks, survey.
ProductivityMonths beside the road; 24-72 hours of closure.
Cost10-30 % above conventional construction for the temporary works; recovered in user-delay cost.

Risks and controls

What goes wrong

  • Differential friction racking the deck, track misalignment, jacks out of sync, weather during the closure.

Quality assurance

Trial slide over a short distance, synchronised jack control, survey at intervals during the slide.

Examples

Utah DOT slides (dozens since 2007), UK railway bridge replacements, Massachusetts Fast 14, Korean railway crossings.

In the bridge game

What Bridge Master applies when you pick it

Deck types: Steel plate girder, Steel box girder, PSC I-girder, PSC box (cast in place), Steel truss, Orthotropic steel box, Steel arch, PSC U-girder, Spliced PSC girder, Voided slab, Precast segmental box, Network tied arch. Spans 30-100 m, up to 150 m.

  • +30: Replace or cross in one possession: slide it in.
  • -35: No reason to slide over open ground.

Try it in the game →

Related methods

SPMT move (self-propelled modular transporters)Precast segmental piers and capsNetwork tied arch constructionTemporary towers and bents for steel erection

Further reading

FHWA Slide-In Bridge Construction Implementation Guide · AASHTO ABC Guide Specifications

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