Elastomeric Bridge Bearing
Structure and Materials
Structure: Typically composed of multiple layers of rubber sheets and thin steel plates stacked alternately, formed into a whole through high-temperature vulcanization technology. The rubber layers endow the bearing with flexibility in the vertical direction, while the steel plate layers restrain the lateral expansion of the rubber, ensuring the structural stability of the bearing under complex stress conditions.
Materials: The elastomeric materials used to manufacture elastomeric bridge bearings are generally natural rubber or synthetic rubber, such as neoprene. These materials have good physical properties and can maintain their characteristics in low-temperature environments.
Working Principle
Vertical Load Bearing: Relying on the composite structure of rubber and steel plates, it reliably transmits the reaction force of the bridge superstructure to the piers and abutments, with sufficient vertical bearing capacity.
Rotational Adaptation: The elastic deformation characteristics of the rubber layers enable the bearing to adapt to rotational deformations at the beam ends caused by factors such as temperature changes and concrete shrinkage. It maintains structural integrity within a certain rotational range to avoid generating secondary stresses.
Horizontal Displacement Compensation: The surface of some elastomeric bridge bearings is covered with a polytetrafluoroethylene (PTFE) slider, forming a sliding interface with a very low friction coefficient with stainless steel plates. This enables millimeter-level horizontal displacement compensation, effectively releasing internal forces in the structure caused by temperature changes, concrete shrinkage, etc.
Types
Ordinary Plate Rubber Bearings: Suitable for bridges with a span of less than 30 meters and small displacements. Rectangular bearings are generally used for orthogonal bridges, while circular bearings are commonly adopted for curved bridges, skew bridges, and circular pier bridges.
PTFE Slider Bearings: The surface of the bearing is covered with a 1.5-3 mm thick PTFE slider, suitable for large-span and large-displacement bridges, such as multi-span continuous beam bridges, simply supported beam continuous slab bridges, etc. They can also be used as sliders in incremental launching construction of continuous beams and for transverse movement of T-beams.
Pot Rubber Bearings: Large-tonnage bridge bearings mainly composed of steel pots, rubber plates, sealing rings, steel liners, etc. They utilize the uneven compression of rubber in the steel pot to achieve vertical load bearing, horizontal displacement, and rotational functions, suitable for large bridges, long-span bridges, and curved bridges.
Characteristics
Advantages: It has good elastic deformation ability, which can absorb the impact energy generated by bridge loads and adapt to various deformations of the bridge; it is simple and convenient to install, requiring no complex installation equipment or technology, which can reduce construction costs and difficulty; it has good durability and corrosion resistance, with a long service life; under normal use conditions, it does not require special maintenance, reducing the operation cost of the bridge.
Disadvantages: After long-term use, rubber materials may experience aging, cracking, and other phenomena, affecting the performance and service life of the bearing; in high seismic intensity areas, ordinary elastomeric bridge bearings may not meet seismic requirements, and special seismic measures need to be taken.
Application Fields
Highway Bridges: Widely used in medium and small span bridges with a high market share, especially suitable for simply supported beam bridges and continuous beam bridges. Their lightweight design can reduce installation costs and shorten the construction period.
Railway Bridges: Through special formula design, they can meet the dynamic load requirements of heavy-haul railway bridges and are also widely used in high-speed railway bridges. The bearings have a long fatigue life to meet long-term use needs.
Municipal Engineering: In structures such as overpasses and footbridges, their maintenance-free characteristics can significantly reduce the life-cycle cost.
Enhance bridge stability with elastomeric bearing in bridges – reinforced rubber-steel pads. Designed for load distribution, vibration damping, and harsh-weather endurance. Fast fit, ISO-compliant. Reliable bearings for resilient bridge projects worldwide.
