The same principles apply to all types of structure where forces are exerted. Bearings can be fixed in both the longitudinal and transverse directions, fixed in one directi on and expansion in the other, or expansion in both directions. Depending on the area of application and country requirements maurer elastomeric bearings can be supplied in accordance with various standards, e. The obstacle to be crossed may be a river, a road, railway or a valley. Bridge bearings are used to transfer forces from the superstructure to the substructure, allowing the following types of movements of the superstructure. This type of bearing supports strong radial loads, but not the axial load. Pot bearings for bridges and structures dec 2012 bearing technologies. A steel rocker bearing consists of a pinned joint to accommodate rotation and a rocker to. While covering the subject of bridge bearings during various courses at iricen the absence of a document covering all aspects of different types of bridge bearings was acutely felt.
Majorspan bridges require special beari ngs to handle their extreme loads, movements, and rotations. Computational analyses of quasiisolated bridges with. Elastomeric bearing with blockades allowing displacement in one direction only. Section 14 discusses the design requirements for bearings. The three new bearing types most widely used today in the united states are pot, spherical and disk. Rocker and pin bearings are primarily used in steel bridges. Abstract steel bridge bearings may be divided into three general types. In highway bridge bearings movements are accommodated by the basic mechanisms of internal deformation elastomeric, sliding ptfe, or rolling. The construction layout sheet in the plans will show the designers intent. Reinforced elastomeric bearings are an often used type of bridge bearings and already been installed in many kinds of structures all over the world. Aashto rubber bearing pads let us support you warco biltrite manufactures a full line of elastomeric bearing pads for bridge, building and reservoir construction markets. Bearings brg missouri department of transportation. Fuller descrip tions of some bearing types, with illustrations, are given in lee. Bridge standard details xs are developed and maintained by the division of engineering services des technical organization.
The design of the bearing may, for example, provide for free linear movement of the moving part or for free rotation around a fixed axis. Laminated rubber bearings provide the simplest method of isolation and are most suitable for high frequency ground motions. Bearing is defined by websters to be a support or supporting part a bearing is a component that allows for relative motion between parts your skeleton is the central structure that supports your body your bodys joints are bearings that allow different parts to move bearings can have many forms, but only two types. Bridge bearings types of bearings for bridge structures and details. Memo to designer s 71 june 1994 bridge bearings introduction aashto defines a bearing as a structural device that transmits loads while facilitating translation andor rotation. Collectively, these bearings are known as high load multi. In general, there are two types of supports shown on plans, fixed f or expansion e.
Steel bridge design handbook bearing design volume 15. Bridge bearingimportance,different type and mechanism. Freyssinet bearings can also be used in a number of other. In a tapered roller bearing, the center lines do not converge at a common point. These bearings may have a rectangular, square or circular section. Information on bridge bearings is available in various technical literatures but it is scattered. These bearing usually allow angular movement of deflection of the girder. Steel bridge bearing design and detailing guidelines introduction the purpose of this guide is to present steel bridge bearing details that are cost effective, functional, and durable. During running, the faces of the bearing pads are separated from the shaft collar by a thin oil. Spherical bridge bearings can be applied to structures with large turning angles, wide and curved bridges regardless of low temperatures even under 30. A rocker bearing is a type of expansion bearing that comes in a great variety.
Types of elastomeric bearing pads construction rubber. The bearings with which we are concerned fit two basic categories ball and roller. A more detailed analysis in bridge bearing design considers the following. December 2, 2015 reduced type iii bearing load capacity. Steel bridge bearing selection and design guide steel building. A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts. Loose needle bearings refer to full complement of needles placed within the annular space between two hardened machine components. Bearings can be fixed in both the longitudinal and transverse directions, fixed in one directi on and expansion in the other, or.
References shown following section titles are to the aashto lrfd bridge design specifications lrfd section 11 discusses the design requirements for bents, piers, and abutments. Various types of bridge bearings are studied in this paper. Pdf modern bridge bearings and expansion joints for road bridges. Most structures require a mixture of bearing types and clients are advised to contact ccl at an early stage to ensure bearings are designed that perfectly match the structure requirements. A support with a f will have a bearing device that will resist longitudinal movements. Inspection and evaluation of bridge bearings topic 9. There are various types of bridges classified based on span, materials, types of bridge structures, functions, utility and position etc. Pdf introduced in 2010 en 37 structural bearings is nowadays. The bridge designer will prohibit movement in some bearings and allow movement in others. These special bearings will not be covered in this section. Spherical bridge bearing features its precisionmachined steel plates with concave ad convex surfaces. This module provides practical information for efficient bearing design and. In addition, we will feature one particular type the tapered roller bearing which has numerous fleet applications. In roller type bearing the metal bearing generate very small horizontal load due to small coefficient of friction.
Versiflex hlmr pot bearing assemblies are especially suited for curved or skewed bridges and other complex structures where the direction of rotation varies or cannot be precisely determined. After a brief discussion of the term bridge bearing and a description of the. Rubber bearing pads dampen vibration and permit for the natural thermal expansion and contraction of structures, whether precast concrete or steel, which aids in prolonging. Types of bridges based on span, materials, structures, functions, utility etc. Bridge bearings 2 types of bearings for a girder bridge. Bridge bearings support structures at a constant elevation, carrying forces from the superstructure into the substructure and allowing necessary superstructure motions to take place. Plain and reinforced elastomeric bearings have become the most common type of bearing in recent years because of their desirable performance characteristics, durability, low maintenance requirements, and relative economy. A drawing showing the bearing layout should include the following. Versiflex hlmr pot bearing assemblies are suitable at locations where lowprofile, highload bearing devices are required. Wisdot bridge manual chapter 27 bearings wisconsin dot.
The sheets contain preengineered details for a variety of structural systems, such as earth retaining systems, bridge railings and underground structures. Types of bridges based on span, materials, structures. As a result of adopting the aashto provisions of 14. Elastomeric bearings for construction industry in neoprene and natural rubber compound.
The required passage may be for a road, a railway, pedestrians, a canal or a pipeline. The separator, which retains the balls or rollers, is. Slab beam beam bridge girder girder bridge truss the girderbeam as well as the truss can be made up of timber, steel or concrete, or can be made up of combination of steel and concrete. A common form of modern bridge bearing is the elastomeric bridge bearing. Another type of bridge bearing is the mechanical bridge bearing. Bearings are made to order to conform to all relevant local and. Brown is available to work closely with bridge owners and engineering design consultants to assist in the design. Section 2 special design requirements for different bearing types.
Types of elastomeric bearing pads plain and laminated elastomeric bearings pads. Wisconsin department of transportation bridge manual. Hlmr pot and disc style, spherical, seismic isolation and elastomeric bearing assemblies for all types of construction. Suitability this type of bridge bearings is suitable for a long span 20m long of the girder bridge. The aptitudes of needle bearings depend of the types of these bearings. Although many different types of bridge bearings have been used by the nysdot, elastomeric and multirotational bearings are the. Bridge design bridge design and assessment bridge bearings.
The designer must determine which bearing type is best suited to cost effectively accommodate the design requirements. This coefficient can be reduced further if the metal rollers are coated with teflon. Bridge bearing types and functional properties continuous bridges with lock up devices bsec lead rubber bearings k eff m t 2. The designer must determine which bearing type is best suited to cost. Bridge bearings until the middle of this century, the bearings used consisted of following types.
Areas of use bearings are most commonly used to provide the connection between the piers and deck of a bridge. The bearing which does not permit any longitudinal movement of the bridge girders is known as the fixed bearing. Technical lecture series indian association of structural engineers bridge bearing types and functional properties seismic isolators. Bearing used in the construction of bridge structure is divided into two major categories namely. Midas e learning midsa civil bearings, piers and abutments part 1. Bridge bearings are devices for transferring loads and movements from the deck to the substructure and foundations. It typically consists of a pin at the top that facilitates rotations, and a curved surface at the bottom that accommodates the translational movements. Steel bridge bearings may be divided into three general types. This iricen publication is a result of the desire to fill the gap. We will discuss both categories, and cover bearing types, installation, operating conditions, maintenance and troubleshooting. Bridge articulation and bearing specification from articulation is the term for the configuration of bridge supports and choice of structural bearings that provides the necessary restraints to the superstructure whilst at the same time providing freedom to some displacements and rotations in order to avoid unnecessary. Computational analyses of quasiisolated bridges with fusing bearing components e. The rolling elements distinguish the two basic bearing types ball bearings and roller bearings.
The original bridge and structures design manual was created through the publicprivate partnership of the georgia department of transportation and the consulting engineering. Bearing types ccl designs bespoke bearings to exacting standards. Trbs second strategic highway research program shrp 2 report s2r19arw2. Several layers are placed on the bridge seat with the superstructure. Elastomeric bearing pads and steel reinforced elastomeric bearings have.
After a brief discussion of the term bridge bearing and a description of the preindustrial beginnings. Post tensioned psc box girder bridge using balanced cantilever method. Ccl advanced solutions help create innovative bearings that anticipate. Three major types of bridge bearings are presented. The maximum allowable compressive stress on the bearing is a function of the shear modulus. Wisdot bridge manual chapter 27 bearings july 2019 273 27. Freyssinets bearings are manufactured in house, ce marked and are officially approved in many countries. Bearing technologies pot bearings in most concrete and steel structures accommodation must be made for relative movement between structural members in order to avoid the buildup of dangerous. In this type of bridge bearing, the rocker pin is eliminated by casting the top of the bottom shoe in the shape of a hemisphere to function as a rocker pin. Steel bridge design handbook fhwa us department of. There are several types of mechanical bridge bearing, such as the pinned bearing, which in turn includes specific types such as. Pin bearing a pin bearing is a type of fixed bearings that accommodates rotations through the use of a.
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