Characteristics of Rubber Bearings for Different Types of Highway Engineering Projects
Common types of rubber bearings used in highway engineering include slab rubber bearings, pot rubber bearings, spherical rubber bearings, etc. Different types of rubber bearings have different characteristics. The following is a detailed introduction for you:
Slab Rubber Bearings
Simple Structure and Low Cost: Mainly composed of rubber sheets and stiffening steel plates, the structure is not complicated, the production process is relatively easy, and the cost of raw materials is also low. Therefore, they are relatively economical in price. They are widely used in medium and small-span bridges and can effectively control project costs.
Good Elasticity and Deformation Capacity: The rubber material itself has good elasticity and can adapt to certain vertical and horizontal deformations of the bridge under the action of vehicle loads, temperature changes, etc. It allows the girder to rotate and move horizontally within a certain range, playing a role in buffering and shock absorption to protect the bridge structure.
Convenient Installation: They are relatively light in weight and have a regular shape. Special large-scale equipment and complex processes are not required during installation. Construction workers can position and install them relatively easily, which can shorten the construction period and improve construction efficiency.
Certain Load-bearing Capacity: By reasonably designing the thickness of the rubber layer and the number of layers of the stiffening steel plate, the vertical load-bearing requirements of bridges of different scales can be met. They are generally suitable for medium and small-span bridges and structures with relatively small loads.
Longer Service Life: Under normal use and maintenance conditions, slab rubber bearings can be used for a long time. However, since the rubber material will be affected by environmental factors (such as ultraviolet rays, temperature changes, chemical erosion, etc.) and gradually age, regular inspection and maintenance are required.
Pot Rubber Bearings
High Load-bearing Capacity: The rubber block in the steel pot is used to bear large vertical loads through its compression deformation under three-way stress. Its load-bearing capacity can range from several thousand kilonewtons to tens of thousands of kilonewtons, which is suitable for large-span bridges with heavy traffic. It can safely and reliably support the weight of the superstructure of the bridge.
Large Horizontal Displacement: Components such as polytetrafluoroethylene sliding plates are installed, which can achieve large horizontal displacements to adapt to the expansion and contraction deformations of the bridge caused by factors such as temperature changes, concrete shrinkage and creep, and vehicle braking forces. The displacement can generally reach ±50mm to ±250mm or even larger.
Good Rotation Performance: The rotation of the pot rubber bearing is realized through the uneven compression of the rubber block. Its rotation angle is generally not less than 0.02rad, which can meet the large rotation requirements of the bridge girder end and ensure the normal working state of the bridge structure.
Good Durability: A sealing device is used to seal the rubber block in the steel pot, reducing the direct contact between the rubber and the external environment, delaying the aging process of the rubber, and improving the durability of the bearing. At the same time, the steel components of the bearing are treated with anti-corrosion measures, enhancing their corrosion resistance.
Relatively Complex Structure: Compared with slab rubber bearings, the structure of pot rubber bearings is more complex, including multiple components such as steel pots, rubber blocks, polytetrafluoroethylene sliding plates, and sealing rings. The manufacturing process requires a higher level, and the cost is relatively high.
Spherical Rubber Bearings
Strong Multi-directional Rotation Ability: Its unique spherical structure enables it to achieve free rotation in multiple directions, with a large and flexible rotation angle. It can adapt to the rotation requirements of the bridge under various complex stress conditions, such as curved bridges and skew bridges. The rotation angle can generally reach 0.05rad or even larger.
Adapt to Large Displacements: It can not only meet the requirements of large horizontal displacements but also adjust the displacement in multiple directions, adapting to the deformation of the bridge under different working conditions. It can effectively reduce the additional internal forces generated in the bridge structure due to unsmooth displacement.
Uniform Force-bearing: The spherical design enables the bearing to distribute the load more evenly when under force, avoiding the phenomenon of local stress concentration, improving the load-bearing capacity and service life of the bearing, and ensuring the stability and safety of the bridge structure.
Good Seismic Performance: Under the action of an earthquake, the spherical rubber bearing can absorb and dissipate seismic energy through its own rotation and displacement, reducing the destructive effect of the earthquake on the bridge structure and improving the seismic performance of the bridge.
High Durability: High-quality rubber materials and special sealing measures are used to prevent rubber aging and the intrusion of external impurities. At the same time, advanced anti-corrosion processes are applied to the steel components, giving it high durability and allowing it to work stably for a long time in harsh environments.
High Requirements for Installation Accuracy: Due to the structural and performance characteristics of spherical rubber bearings, high requirements are placed on the installation accuracy. The installation process needs to be strictly controlled to ensure that the bearing can function properly.
In summary, different types of rubber bearings for highway engineering have their own characteristics. In actual projects, it is necessary to comprehensively consider factors such as the span, load, structural form, and usage environment of the bridge and select the appropriate type of rubber bearing.
