Bridge Bearing Plates Introduction
Bridge bearing plates are a series of fabricated steel plates used in bridge bearing assemblies, there are top bearing plates, bottom bearing plates, and embedded bearing plates. Embedded bearing plates are usually pre-installed in concrete structure of composite or steel box bridge girders, these plates are usually made of hot-dip galvanized steel plates (Q345 or equivalent grades). Bridge bearing plates can increase the bridge girder’s impact resistance and enlarge the contact area at the stress points, make sure the bridge bearings are functioning normally.
Bridge Bearing Plate Specifications
- Steel Materials: Q355D (steel plate), 45# steel (sleeve), HPB300 (anchor bar)
- Surface Treatment: Multi-element powder co-diffusion treatment + passivation + sealing
- Applications: The bridge bearing plates are assembled in the bridge bearing structure for various bridges. It is used not only for building railway bridges, highway bridges, and even cross-sea bridges.
Working Principle of Bridge Bearing Plate: It has high performance of bearing the load and impact of locomotives and rolling stock, and at the same time have good fatigue resistance and corrosion resistance. They are connected to the bridge bearing to stably keep the bridge girder on bridge pier.
Bridge Bearing Plates Types for Sale
AGICO is an experienced bridge bearing plates supplier, we mainly offer embedded bearing plate, PTFE skateboard bearing plate, leveling wedge plate. According to the bridge type, bearing form, and slope requirements, bridge bearing plates can be divided into the following 4 types, and their specifications must strictly match the design requirements:
- Steel Material: Q235 or Q345 hot-dip galvanized steel sheet, typically 20mm thick.
- Specifications: Common sizes include 690×600×20mm and 840×640×20mm, and can be customized according to the bridge girder length.
- Applications: Used for simply supported girder structures of highway and railway bridges when there is no need for the supports to slide.
- Steel Material: Q235 or Q345 hot-dip galvanized steel sheet, typically 20mm thick.
- Specifications: Common sizes include 690×600×20mm and 840×640×20mm, and can be customized according to the bridge girder length.
- Applications: Used for simply supported girder structures of highway and railway bridges when there is no need for the supports to slide.
- Steel Material: It is medium-thick plate made of Q235B steel, with surface treatment of hot-dip galvanized for rust prevention.
- Thickness Range: 2mm to 100mm, with common thicknesses being 20mm and 30mm.
- Size Range: 100×200mm to 1000×2000mm, customizable according to slope.
- Application: Fix bearing tilt caused by longitudinal or transverse slope of bridges
- Steel Material: Weather-resistant steel or stainless steel is used to improve corrosion resistance.
- Increased Thickness: Thick plates (e.g., 50mm or more) are used for ultra-long span bridges.
- Surface Treatment: Multi-alloy co-diffusion or passivation treatment to enhance durability.
- Application: Special environments such as cross-sea bridges and bridges in high-altitude and cold regions.
AGICO also supplies customized fabrication of high-strength bridge bearing fasteners, including large hex bolts and embedded bolt sleeve, if you are interested in bridge bearing solutions, don’t hesitate to send a free quote now!
Quality Control in Steel Bearing Plates Fabrication Process
Steel Bearing Plate Fabrication Process
Quality Control Measures
The machining accuracy of the Steel bearing plates directly affects the safety of the bridge, quality control of the fabrication process at AGICO must comply with the following process:
Material Cutting And Molding:
- CNC and laser cutting machines are used for precise material cutting, with the error controlled within ±1mm.
- The wedge-shaped steel plate needs to be processed by milling equipment, to ensure that the slope accuracy meets the drawing requirements.
Welding and Corrosion Protection:
- The anchoring reinforcement welding of sleeves adopts a segmented short welding process to prevent the steel plate from deforming due to heat.
- The surface of bearing plate is hot-dip galvanized, which requires zinc layer thickness of ≥85μm, meeting the C4 level corrosion protection requirements.
Installation and Acceptance:
- Fit test: The gap between the bridge bearing and embedded plate in concrete must be filled with epoxy resin mortar with the same strength as the pad stone.
- Positioning accuracy: The center distance of the bridge bearing plates is 10-30mm longer than the design value, for the bridge girder length change by tension and shrinkage.
Bridge Bearing Embedded Plates In Concrete
Precise Positioning of Embedded Steel Plate
The center of the steel plate is typically exposed about 0.5 cm below the beam soffit for fine adjustment, or it may be integrally cast with the concrete wedge block, leaving about 5 cm of the supporting centerline exposed below the beam for subsequent alignment.
Custom-Made Leveling Wedge Plates
Wedge plates are processed according to the bridge slope design drawings. This plate part is generally made of Q235 or Q345 steel, which has high strength and fatigue resistance. The wedge plate shape can be quadrilateral, rhombus, circular, or irregular rectangle to meet different engineering needs.
Install Methods Options:
- Method 1: Set concrete wedge blocks at the bottom of the precast slab and cast it together with the hollow slab.
- Method 2: Set leveling steel plates at the support points of the precast slab for longitudinal and transverse leveling.
- Method 3: Add a wedge-shaped leveling steel plate between the embedded steel plate and the top of the support; the steel plate needs to be ground to adapt to the slope.
Bridge Bearing Plates Standard and Installation in China
Bridge Bearing Plates Implementation Standard:
- Q/CR749.3-2020 Protective coatings and paints for steel structures and components of railway bridges.
- Tongqiao 8360 “Installation Drawing of Pot-Type Rubber Bearing for Commonly Used Span Simply Supported Beams on Passenger Dedicated Railway Lines”
Bridge Bearing Plates Installation Instructions:
- During bridge girder prefabrication, according to the construction drawings, first place the support embedded plate in the fixed position at the bottom of the beam, keep it sealed, and prevent grout leakage.
- Grease should be applied to the internal threads of the sleeve, and protective measures should be taken to prevent sand, gravel, and other debris from entering the sleeve.
- Reinforcing bars can only be tied after the position has been calibrated.
