Casting Of Girders For Superstructures in Viaduct of Metro

                                          Girder

●     Girder is the superstructure of viaduct on which the rail tracks are laid and train runs.

●      It rests on the piers, one at each end.

●      Since we have two tracks, each pier supports four U girders (two on each side)

●      U girder weighs around 140 Tons and is 25 m long.

There are 3 bed in the Casting Yard for both U girders and pier cap –

• Caging Bed

• Casting Bed

• Curing Bed

Each Bed is Capable of Making four Girders simultaneously in a row.

Methodology :

1.    Four Cages are fixed at the Cage Bed.

2.    Cleaning And Oiling of Mould/Shuttering of Casting bed is done.

3.    Lifting Of Cage and Shifting to Casting Bed is done.

4.    End Shutters are fixed.

5.    High Tensile Stress (HTS) Cable and Pre-tensioning prestressing cables are placed.

6.    Inner Shutters are fixed.

7.    Pre tensioning of prestressing steel is done.

8.    Concrete of Specific grade of Concrete is used in pouring and compacted using needle vibrators.

9.    Curing is done.

10.                    De-Shuttering is done when Concrete gains required Strength i.e., after 3-4   days.

11.                    Lifting and Shifting of Girder to Staking Yard.

12.                    Finishing of Girder after 21 Days.

Caging Bed For Reinforcement of U-Girders

Typical Cross-section of the Metro Station

Curing of The Girders with a rigid Support between them

Typical Viaducts for the Metro Construction

Viaduct of U-Girders in Mumbai Metro line 7