Technical Support
Structural Bearings
Structural Bearings
Structural Expansion Joints
Pre Stressed Slab
Bearings are to be installed with due care to ensure their correct functioning in accordance with the design of the Structure. The factors to be considered during the Installation of the Bearings are :-
Bearings shall be so located as to avoid accumulation of dirt & debris and also from rain water seepage that may affect their performance.
Provision of Jacking Points shall be made during the design / construction of the Structure to facilitate the Lifting of the Superstructure in future for the Maintenance or removal of the Bearings.
The Bearing manufacture shall be consulted at an early stage of the structure design for tentative Bolt Locations so that the hassles of Tandons / Prestressing Strainds fouling with the Bearing Dowels shall be avoided.
Bearings are to be supplied with suitable Identification Plates & proper marking on top of the Bearing showing Type, Capacity and Direction of the Bearing.
Bearings shall be Provided with Transport Brackets firm in position, painted with red Color for distinguished appearance.
Bearings shall be Packed in Heavy Duty Polythene Sheets and firmly clamped on the Wooden crates for safe Transportation.
Transport Brackets are not to be relied for the Lifting of the Bearings.
Upon receipt of the Bearings at Site, the contractor shall have a visual Examination of the bearings to ensure that no damage of Displacement of the bearings is taken place during the Transportation. Any rectification if required shall be done strictly in the presence of the Manufacturers Representative.
Bearings shall be installed truly horizontal with Top & Bottom Components of the Bearings perfectly parallel to each other.
The positioning of the Bolts & Bowels for Both the Substructure as well as the Superstructure shall be made as per the Shop Drawings.
The Dowels / Distribution Plates shall be Properly grouted with suitable grout material.
In case of Moving Bearings, particular care shall be taken to ensure the correct Orientation of the Bearings.
In In-situ type of Construction the Bearings shall be covered from all sides to avoid the ingress of cement slurry etc. inside the bearing Components.
In case of Pre-cast Construction, due care is to be taken while launching the Girders on to the Bearings. Girders shall not be rested freely over the Bearings without any Support.
Transport Brackets shall be removed at an appropriate time after the setting of the Superstructure Concrete.
Bearings and its components shall be checked for any dust, dirt or Cement Slurry Deposit etc. and the surrounding area shall be cleaned thoroughly once the Process of bearing Installation is over.
Pot / Pot - cum - PTFE Bearings because of their proven Experience in the past are regarded as virtually maintenance free Bearings and performs satisfactorily throughout the service life of the Bridge Structure.

However, further to ensure safe and sound performance of the Bearings during the Service life routine maintenance schedule shall be planned and implemented an appropriate interval of 2 to 3 Years. The factors to be given Importance during the Inspection are :

Measurement of Movement
Measurement of Dimensions
Evidence of locked in Condition
Evidence of Corrosion
Condition of the adjacent Bridge Structure
Necessary Repair and / or Replacement of the Damaged Components shall be taken on Priority in consultation with the Bearing manufacturer.

In case of defects where the cause cannot be determined by the inspecting person or the responsible Bridge Engineer, the bearing manufacturer shall be consulted.