Segmental Launching Gantry

Segmental launching gantry is generally used for erecting small and medium spans, road bridges and subway bridges assembled with prefabricated and prestressed concrete box girders (PC girders). The main features are high construction efficiency and can self moving. It is generally composed of the main girder, supporting legs, hoisting trolley, etc. The main girder is used for bearing and the supporting legs performs the whole machine horizontal movement, vertical movement, leveling, supporting, crossing, side shifting and other functions. The hoisting trolley is for beam lifting.


Device type

1.        Full symmetrical suspension

2.        Symmetrical suspension + half span suspension

3.        Full span suspension

Working principle:

        Feeding beam by transportation trolley or vessel( two way: under the bridge or at the end of the bridge), segmental launching gantry picks up each segmental beam and hangs on the main beam; accurate registration, applying glue, and forming the whole beam. Then segmental launching gantry will place the finished beam on the bridge pier and connect it with adjacent bridge through wet joint.  Single span erection is completed. Segmental launching gantry moves across and continue the next segmental beam construction.

Main technical data for design:

The selection design shall provide the bridge design drawings and party A's technical requirements, including the design of the lower pier structure, the upper beam and the site working environment, the main technical parameters to be specified as below:

1. Maximum section beam lifting weight;

2. Maximum hanging weight;

3. Span of bridge opening;

4. Section size of segment block and position of lifting point;

5. Bridge pier section size, height and bearing capacity of bending;

6. Bridge deck longitudinal slope and transverse slope;

7. The minimum curve in the section;

8. Beam selection.

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