Realignment of Bridge

Realignment of bridge spans is required where the girders were displaced from its original position on bearing pads. These displacements occur due to the lateral movements of bridge decks and the main reason of lateral movements is of missing/ not constructed proper shear keys. To realign the deck slabs, the girders will be place on the bearing pads. Therefore, following steps should be followed for realignment of bridge spans.

STEPS:

1. Installation of steel brackets on both ends of transom using 9 No .dia 25mm bolts 300mm long as shown in drawings.
2. Placing two 75 tons low height hydraulic Lifting jacks under each girder (i.e. 5 girders) and also two 250 tons jacks under each of 4 diaphragms. Total hydraulic jacks required are = 5×2+4×2 = 18
3. Lifting of deck slab including girders in a synchronized manner.
4. Removing bearing pads and placing of deck sliding arrangement (sandwich sheets of stainless steel sheet 2” thick and Teflon sheet 1/2” thick).
5. Lowering the deck slab on to the sandwich sheets.
6. Fixing the jacks in between girder and steel brackets.
7. Pushing the deck in the horizontal direction with hydraulic jacks to bring the deck on its original position.
8. Lift the deck girders again and remove the sandwich sheets.
9. Placing the existing bearing pads on its original position.
10. Putting back the deck on the bearing pads.