Precast Segmental Erection

Balanced cantilever erection with launching gantry

The prefabricated segments are transported by truck or barge to the erection site. They are then installed symmetrically on either side of the supports using gantry cranes, floating cranes, or mobile handling equipment fixed to the deck and launching girders. This construction method is adapted to long structures (deck spans from 30m to 60m) with multiple spans; it combines the advantages of cantilever construction together with segment prefabrication.

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High erection rate 1 or 2 pairs of segments per shift

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Minimal disruption Maintains traffic flow on existing roads and services below

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Clear access Simultaneous access to several work fronts

Span-by-span erection with underslung gantry

An entire span of precast segments is assembled on a temporary supporting truss (underslung or overhead gantry) between two piers. Once all segments are aligned and epoxy joints are applied, longitudinal post-tensioning is stressed to make the span self-supporting before the gantry advances to the next span. This method is highly efficient for elevated metro corridors and long viaducts with uniform span lengths.

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Maximum Speed Ability to complete an entire span in a few days

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Consistent Quality Leverages factory-controlled segment prefabrication

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Reduced Formwork Eliminates the need for ground-supported falsework

Progressive placement method

Building over deep water, steep valleys, or environmentally sensitive zones? Our progressive placement method offers the ultimate top-down bridge construction solution where ground access is restricted or impossible. By sequentially placing segments from one end of the structure to the other—utilizing temporary stays and masts to support the cantilever—we ensure flawless execution without disrupting the ecosystem below.

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Top-Down Execution Zero footprint required at ground level between piers

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Environmental Protection Ideal for protected ecological zones and deep rivers

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Equipment Flexibility Can be executed using deck-mounted lifting frames

Ground-supported crane erection

For bridges with low clearance or accessible terrain, heavy crawler cranes or mobile cranes are utilized to lift precast segments directly onto temporary scaffolding or falsework towers. This conventional approach provides high flexibility for varying span lengths and complex geometries, avoiding the mobilization costs of heavy, specialized launching gantries.

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Cost-Effective Low equipment mobilization costs for accessible sites

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High Adaptability Easily handles varying span lengths and tight curves

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Rapid Deployment Standard crawler cranes can be mobilized quickly