Products
Pot Bearing

1. Principle

GTP-Pot Bearings are used to transfer all loads from superstructure to substructure, and also facilitate movements in every direction and rotations about every axis.

GTP Pot bearings can be fabricated and designed in accordance with EN1337-5, BS5400 or AASHTO LRFD bridge construction specifications, as appropriate.

2. Structures

w Pot: A steel cylinder recess which confines the elastomeric disc throughout its service life.

w Elastomeric disc: A rubber pad which, under high pressure, acts as confined fluid and enable the piston to tilt and then to accommodate the rotation of the structure. The deformation of elastomeric disc defines the rotation capacity of bearing.

w Sealing ring: Three layers of brass rings which prevent escape of elastomer under compressive load and simultaneously applied rotation.

w Piston: An intermediate circular steel made plate which supplies a high capacity of loading-transfer, and provides a recess to house the dimpled PTFE sheet. For the inner guided pot bearing, piston typically provides a centrally arranged key (guide bar) to resist the horizontal load and determine the direction of bearing.

w Sliding mating surface (typically PTFE&SS plate): Consists of a dimpled PTFE sheet and a stainless steel plate which remains flat and in full contact with top plate and completely covers the PTFE sheet under maximum displacement. The friction coefficient of these two parts remains at a low level, less than 0.03.

w Top/sole plate: It helps to keep the flatness of SS plate and plays a supporting role.



3. Application and advantage

GTP Pot bearings can be widely engineering applied since the following superior performance:

w Transferring very large vertical load, it is possible to cover a wide range from 1000kN to 80000kN.

w Theoretically transferring horizontal force with no limitations

w Accommodating horizontal movement with no limitations

w Typically allowing rotation capacity up to ±0.02rad

w Convenient to manufacture and install

w High reliability, durability and easy maintenance

4. Types

GTP Pot bearings are generally classified into the followings three categories:

GTPF——Fixed bearing which resists horizontal force in every directions but allows rotations about every axis.

1-top plate2-sealing ring3-elastomer disc4-piston5-anchor bolt6-sleeve7-washer8-dust protection

GTPG——Guided sliding bearing which resists horizontal force in only one direction and slides along the perpendicular direction, and allows rotations about every axis as well.






1-top plate12-SS plate3-PFTE4-piston5-sleeve6-washer7-anchor bolt8-pot9-elastomer disc 10- sealing ring11- dust protection12-Composite material13-SS plate

GTPM ——Free sliding bearing which allows movements in every direction with no horizontal resistance and rotations about every axis.

1-top plate12-SS plate3-PFTE4-piston5-sleeve6-washer7-anchor bolt8-pot9-elastomer disc 10- sealing ring11- dust protection12-Composite material13-SS plate

GTPM ——Free sliding bearing which allows movements in every direction with no horizontal resistance and rotations about every axis.


1-top plate12-SS plate3-PFTE4-piston5-sleeve6-washer7-anchor bolt8-pot9-elastomer disc 10- sealing ring11- dust protection12-Composite material13-SS plate

GTPM ——Free sliding bearing which allows movements in every direction with no horizontal resistance and rotations about every axis.


1-top plate12-stainless steel plate3-PFTE4-piston5-sleeve6-washer7-anchor bolt8-pot(basin)9-elastomer disc 10-brass seal11- dust protection

5. Raw Materials

The materials used are typically in accordance with AASHTO standard, or European standard EN1337 as clients’ requirements.

w The structural components of the bearings are made of ASTM A709/A709M Grade 36 or higher quality.

w Elastomer used in the elastomeric disc is chloroprene rubber (CR) with hardness ShA 60±5 or natural rubber (NR) with hardness ShA 50±5 for low temperature.

w PTFE surface are made from virgin PTFE resin or blended with fiber (glass or carbon).

w Sealing ring between the piston and elastomeric disc are made of brass rings of rectangular cross-section.

w Stainless steel conform to the requirements of ASTM A240/A240M, Type 304 with a minimum thickness of 20 gage.

6. Anchorage system

Anchorage system is used to connect the superstructure and substructure and resist the horizontal force. Typically:

w For steel structure

1. Shear pins

2. Anchor bolts

w For precast concrete structure and cast in situ structure

1. Shear pins

2. Anchor bolts connecting to masonry plate

3. Anchor bolts connecting to threaded socket