This standard specifies the requirements for materials, design, fabrication, testing, and installation of pot bearings for use in bridges. It covers fixed, free, and guided pot bearings, detailing the properties of steel components, confined elastomer discs, and PTFE sliding surfaces.
Specifies material, design, manufacturing, testing, and acceptance requirements for pot bearings used in bridges.
Quick Reference Values
Elastomer hardness50 ± 5 IRHD
Maximum average pressure on elastomer (SLS)35 MPa
Proof load for vertical load test1.25 x Design Vertical Load
Minimum thickness of pot wallGreater of Di/30 or 6 mm
Minimum thickness of confined PTFE sheet4.5 mm
Coefficient of friction for dimpled PTFE (max)0.03 to 0.08 depending on pressure
Key Formulas
σ_c = 4V / (π * Di^2) ≤ 35 MPa — Check for average pressure on elastomer
t_pot ≥ Di / 30 — Minimum thickness of pot wall
e_max / Di ≤ 0.005 — Check for elastomer thickness variation
Practical Notes
Ensure strict adherence to the surface finish requirements for stainless steel and PTFE mating surfaces to achieve the desired low-friction performance.
The sealing rings are critical to prevent elastomer extrusion and contamination; their proper seating and material quality must be verified during inspection.
Installation requires high precision. The bedding mortar level and bearing orientation must be exact as per drawings to avoid inducing unintended stresses in the superstructure and substructure.