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What are the characteristics of friction pendulum ball bearings for highway bridges

Source:www.jswanbao.com      Release date: 2024-12-04
Friction pendulum ball bearings for highway bridges have the following characteristics: 1.Superior mechanical performance Strong bearing capacity: able to withstand large vertical loads, its vertical planning bearing capacity usually has multiple levels to choose from, ranging from hundreds to thousands of tons, which can meet the bearing needs of highway bridges of different scales. For ex
Friction pendulum ball bearings for highway bridges have the following characteristics:
1.Superior mechanical performance
     Strong bearing capacity: able to withstand large vertical loads, its vertical planning bearing capacity usually has multiple levels to choose from, ranging from hundreds to thousands of tons, which can meet the bearing needs of highway bridges of different scales. For example, some large cross sea or cross river bridges can reliably support the huge weight of the upper structure of the bridge using friction pendulum ball bearings
     Good adaptability to horizontal forces: The bearings can effectively resist the horizontal forces generated by the bridge during use, such as vehicle braking, wind loads, seismic effects, etc. The horizontal bearing capacity of fixed bearings in all directions and one-way movable bearings in the non slip direction can reach a certain proportion of the vertical planned bearing capacity of the bearings, generally 10% -20%, to ensure the stability of the bridge under horizontal force
2.Good rotational performance
     Large turning angle capability: The design turning angle can usually reach 0.05 rad or more. Compared with ordinary bearings, it can better adapt to the large turning angle deformation generated by bridges in complex stress states, such as curved bridges, wide bridges, etc., when subjected to vehicle load eccentricity or temperature changes
     Stable rotational torque: The rotational process is achieved through the sliding of a spherical PTFE plate, with a small rotational torque that is only related to the radius of the support sphere and the friction coefficient of the PTFE plate, and is independent of the size of the support angle. This enables the support to maintain relatively stable rotational performance at different angles, which is beneficial for the uniformity and stability of the bridge structure
3.Strong adaptability to displacement
     Large displacement: The displacement of the movable support is relatively large, with a displacement in the longitudinal direction of the bridge generally ranging from 50mm to 150mm, and a displacement in the transverse direction of the bridge ranging from 20mm to 40mm. It can meet the expansion and deformation requirements of the bridge under the influence of temperature changes, concrete shrinkage and creep, and effectively avoid excessive internal stress in the bridge structure caused by limited displacement
     Multi directional displacement function: Bidirectional movable supports have vertical rotation and longitudinal and transverse sliding performance, which can adapt to the deformation of bridges in multiple directions, ensure the continuity and integrity of bridge structures, and are particularly suitable for bridge structures under complex stress states, such as curved beam bridges, inclined bridges, etc
4.Excellent friction characteristics
     Low friction coefficient: Under silicone grease lubrication, the friction coefficient of room temperature bearings is generally small, usually around 0.03. The friction coefficient of cold resistant bearings can also be controlled within 0.06 in low temperature environments (-40 ℃~+60 ℃), effectively reducing the friction force of bearings during rotation and sliding, reducing the additional internal forces of bridge structures, and improving the service life of bearings
    High stability of friction coefficient: Using special friction materials and surface treatment processes, such as spherical PTFE plates, the friction coefficient of the support can remain relatively stable during long-term use, without significant fluctuations due to environmental factors, frequency of use, and other changes, ensuring the reliability of the mechanical and usage performance of the support
5.Good durability
     Excellent Material: The main components of the bearing are usually made of high-strength steel, wear-resistant materials, etc. For example, the ball crown liner plate is made of modified ultra-high molecular weight polyethylene and other wear-resistant materials, which improves the wear resistance, sliding performance, and impact resistance of the bearing, and extends its service life
     Complete protective measures: The surface of the support is generally treated with anti-corrosion measures, such as galvanizing, epoxy coating, etc., to prevent rusting and corrosion of the steel; At the same time, rubber sealing rings, dust covers and other sealing devices are installed in some key areas to prevent dust, moisture and other impurities from entering the interior of the support and affecting its normal operation, further improving the durability of the support
6.Outstanding seismic performance
     Significant seismic isolation effect: Under earthquake action, friction pendulum ball bearings can dissipate seismic energy and reduce the seismic response of bridge structures through the sliding and swinging of the spherical surface, thereby achieving the purpose of seismic isolation and protecting the safety of bridge structures. In bridge construction in earthquake prone areas, the use of friction pendulum ball bearings can effectively improve the seismic resistance of bridges
     Reliable seismic resistance structure: The support is equipped with shear blocks, high elastic damping elements and other seismic resistance structures inside. When the horizontal thrust exceeds the horizontal limit design shear bearing capacity of the support, the shear pin is damaged, and the high elastic damping elements act as a buffer to achieve the damping seismic resistance function of the support, preventing serious damage to the support and bridge structure
7.Easy installation and maintenance
     Easy installation: By using sleeves and anchor bolts to connect with piers and beams, the accessory components are designed flexibly and the installation process is relatively simple, which can effectively shorten the construction period of the bridge and reduce construction costs
     Easy to maintain: The structural design of the support is reasonable, making it easy to inspect and maintain. During use, regular inspections, cleaning, lubrication, and other maintenance work can be carried out on the support to promptly identify and address any potential issues, ensuring the normal use of the support.