What are the different bearings used in bridge?
Types of bridge bearings
- Rocker bearings.
- Elastomeric bearings.
- Sliding bearings.
- Spherical bearings.
What is the span of expansion bearing?
An expansion bearing permits only end rotation and also longitudinal movement of the supported member. Where the spans exceed 15 m, the bearings should be designed to allow end rotation.
Why bearings are provided in bridge?
A bridge bearing carries the loads or movement in both vertical and horizontal directions from the bridge superstructure and transfers those loads to the bridge piers and abutments. The loads can be live load and dead load in vertical directions, or wind load, earthquake load, etc., in horizontal directions.
What is preset in bridge bearings?
Note: “Preset” refers to the displacement of a certain distance of sliding bearings with respect to upper bearing plates during installation of bearings. Preset is a technique to decrease the measure of upper plates of sliding heading keeping in mind the end goal to spare cost.
How many types of bearings are there?
Here, we’ll look at the 6 most popular types: plain bearings, rolling element bearings, jewel bearings, fluid bearings, magnetic bearings, and flexure bearings. Plain bearings are the simplest type of bearing and are composed of just the bearing surface with no rolling elements.
What is expansion bearing in bridges?
Expansion bearings provide for rotational movements of the girders, as well as longitudinal movement for the expansion and contraction of the bridge spans. The function of the fixed bearing is to prevent the superstructure from moving longitudinally off of the substructure units.
What is the maximum length for expansion joint?
As per IS- 456:2000, structures exceeding 45m in length are designed with one or more expansion joint. As per IS 3414 which is a specific code for joints, it is mentioned as 30m. Expansion joint shall be so provided that the necessary movement occurs with a minimum resistant at joint.
What is the standard width of expansion joint?
Expansion joints should be wide enough to prevent portions of the building on either side of the joint from corning in contact, when the structure is subjected to the maximum expected temperature rise. Joints vary in width from 1 to 6 in. (25 to 152 rom) or more, with 2 in. (51 rom) being typical.
Why are steel plates inserted inside bearings in elastomeric bearings?
To increase the compression stiffness of elastomeric bearings, metal plates are inserted. After the addition of steel plates, the freedom to bulge is restricted and the deflection is reduced when compared with bearings without any steel plates under the same load.
What is the bearing specification?
A bearing number is composed of a basic number and a supplementary code, denoting bearing specifications including bearing type, boundary dimensions, running accuracy, and internal clearance.
What is K type bearing?
Type K is a mounted tapered roller bearing with reduced length through bore. Durable twin row tapered roller bearing with single spring lock collar and variety of mounting styles.
What is type of expansion bearing?
The expansion (EX) bearing has a plain outer race roller track. This bearing takes radial load only. The inner race is clamped to the shaft, and moves axially with it when expansion or contraction occurs.
What are the dimensions of a bridge bearing?
inches at abutments and 4 inches at hinges. Plan dimensions (length, width) are determined in two inch increments. Maximum dimensions should not exceed 30 inches. The minimum shape factor (5) for any reinforced bearing shall be 5.0.
Why do you need elastomeric bearings for a bridge?
The typical hinge or abutment configuration using many small elastomeric bearing pads has proved highly reliable and redundant. In addition, these bearings are extremely forgiving of loads and translations exceeding those considered in design. Designing and Detailing Notes
Who are the design teams for bridge bearings?
Design teams are from both structural and mechanical engineering backgrounds, to allow the structural design needs of the client to be combined with a bearing that can be optimised in terms of manufacture and cost.
Which is the best quality management system for bridge bearings?
Delivering quality at every stage, all bridge bearings are designed individually to exacting standards using high specification materials from approved sources. The latest design software and FEA is used to optimise bearing design for efficiency and cost. CCL’s quality management system complies with EN ISO 9001.