6/17/2024

The Incredible Impact of Install Spherical Bearings

Traditionally, steel Rocker-Roller bearings have been used for bridges with higher spans across various industries. These bearings, while reliable, require significant maintenance efforts, are heavy, and can be difficult to replace. New options including spherical and Pot-PTFE bearings are now possible because of developments in bearing technology. Spherical bearings, in particular, are being increasingly adopted due to their capability to handle high vertical and horizontal loads. The use of spherical bearings offers significant advantages, including reduced maintenance costs and an extended lifespan.

Their ability to accommodate frequent high displacements under substantial vertical loads makes spherical bearings an optimal choice for bridge applications across different sectors. This blog will explore the rationale behind the decision to adopt spherical bearings and the process of installing these bearings in bridge superstructures.

When considering spherical bearings, it's important to note the different types available. One notable type is the Spherical Bearing Fixed Type, which is designed for permanent installation without the need for movement adjustments. This fixed type provides enhanced stability, reduced maintenance requirements, and long-term reliability, making it suitable for areas where stability and load-bearing capacity are crucial.

 

Spherical Bearing Fixed Type

During the installation of fixed-type spherical bearings, precision alignment and adherence to specified tolerances are crucial for optimal performance. These bearings, designed for permanent fixation, provide stability and load-bearing support without requiring movement adjustments.

The installation process involves securely fastening the bearings to the bridge structure and verifying alignment using precision measurement tools. Fixed-type bearings are chosen for their ability to withstand high loads and contribute to the bridge's structural integrity. Following installation, regular upkeep and observation guarantee lifespan and continuing function.

Installing bearings is a critically important process. Incorrect techniques can cause damage to bearings, which are both costly and difficult to procure. The best approach is to use tools that have been specifically designed and refined over time to ensure repeatability, reduce installation time, and save money. Deevin, with its decades of experience and extensive application knowledge, is well-equipped to assist you promptly with your projects.

The installation process demands high technical expertise and precision machining of housing surfaces. Specialized tools and equipment are essential, and space constraints can complicate installation. Although, Installing can be a challenging task due to several factors:

  • Precise Alignment: Ensuring correct alignment to prevent uneven load distribution and premature wear.
  • Handling and Transportation: Managing the weight and size of bearings without causing damage.
  • Environmental Conditions: Dealing with extreme temperatures or corrosive environments.
  • Technical Expertise: Requiring high-level skills and experience for proper installation.
  • Housing and mounting surfaces are matched to bearing specifications by precision machining.
  • Specialized Tooling: Needing specific tools and equipment for correct installation.
  • Space Constraints: Working in limited spaces can complicate the installation process.
  • Expense and Time: Should problems emerge, the procedure may be costly and time-consuming.
  • Safety Concerns: Ensuring worker safety during the handling and installation of heavy components.

At this point, spherical bearings were the only viable option for the bridge. A set of mating concave and convex steel backing plates with a low-friction sliding surface enable rotational movement through curved sliding in spherical bearings, which are structural elements. To allow this movement, the bearings incorporate flat sliding elements, guides, and restraining rings.

 

Installation Of Spherical Bearings

  • When installing the bearings, care must be taken to ensure that the structure can use them correctly.
  • Accredited installation It shall be maintained that the bearing's tolerance from the sliding plane.
  • The installation method will need to be examined and approved by the engineer.
  • Bearings must be modified as needed to account for the temperature during installation, future temperature variations, residual creep and shrinkage of the bridge deck, falsework release, and any pre-stressing-related bridge shortening (if any).
  • The bedding surface must be in touch with the bearings during their entire placement. Hard places or voids following installation are not acceptable. After installation, care must be taken to ensure no air pockets beneath the bearing bottom plate.

 

Installation Tolerances

Setting Up Tolerances for spherical bearings are essential for longevity and optimum performance. These include precise dimensions, accurate alignment,  correct positioning, smooth surface finish, proper bolt tightening,  controlled gaps and clearances, and consideration of temperature variations. Adhering to these tolerances ensures reliable function and effective load handling for bridge structures.

 

Inspection During Installation

During the installation of spherical bearings, expert supervision from the manufacturer, such as Deevin, is essential as they provide guarantees for the bearings. The process involves aligning the girder using jacks, ensuring consistent levels at all four corners with a level instrument, and controlling alignment using a Total Station instrument.

Girders will be supported by lifting jacks with PTFE sheeting for smooth movement. After installation, the final alignment, levels, and camber of the girder will be checked and recorded. A gauge will be used to set the measurement of girder movement to zero post-installation.

Ultimately, the adoption of spherical bearings represents a significant advancement in bridge engineering, offering enhanced load-bearing capabilities and reduced maintenance needs. By understanding the types, installation processes, and meticulous alignment requirements, engineers can ensure the longevity and reliability of these bearings. As the industry continues to evolve, spherical bearings will undoubtedly play a crucial role in modern bridge construction and maintenance.