The information included is intended to permit efficient fabrication, installation, and maintenance of these bearings. Notes on bridge abutment design and the loads that need to be considered. 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. Furthermore, if the horizontal shear force is greater than onefifth of the minimum permanent dead load, the bearing. Pot bearings are special types of bearing pads for taking larger loads, translation and rotation in confined areas. Rotation may occur on any axis and is accommodated by deformation of the elastomeric pad. Pdf bearing is very small part of bridge compared to all other components. As all the loads from the superstructure are transferred through the bearing and the movement is also controlled, albeit being a small item in the overall bridge. Bridge bearings types of bearings for bridge structures and. The same principles apply to all types of structure where forces are exerted.
Uplift forces are also seen on some curved girder bridges and in flood prone regions where high water can result in the bridge becoming buoyant. Standard specifications for bridge construction section 1, excavation march 20 1 1 1. Disktron bearings can be easily modified for uplift restraint which is common in seismic zones. Bridge bearings, structural bearing, ptfe sliding bearing. Wisdot bridge manual chapter 27 bearings july 2019 273 27. Bridge bearings are the largest materials handling bearing manufacturer and supplier in the uk. Anulab pot cum ptfe bridge bearing 260 mt rotation test as per irc 83 part iii. Fhwa bridge inspection manual section 9 bridge bearings.
Haines research report 42 research project 04 elastomeric bearings conducted for the texas department of transportation in cooperation with the u. For circular bearings, stability may be investigated. A uniaxial displaceable pot bearing guided pot bearing releases the lateral movements of bridge in any one direction utilizing a guide on the lid and a guiding groove in the gliding plate. Many of our products are available either sealed or unsealed and are suitable for. Possible causes of movement are thermal expansion and contraction, creep, shrinkage, or fatigue due to the properties of the material used for the bearing. Posted on june, 2018 august 21, 2018 author sundari comment0 abstract.
Bearing design spread sheet based on aashto 16th edition 1197 interim method a aashto lrfd by arp visit. Design guidelines for bridge widenings, steelreinforced elastomeric bearings fo r pretensioned concrete beams, stru tandtie method, and culverts. During the earthquake, all bearings under the superstructure of this bridge have been damaged figures 195 and 196. Besides the functional requirements, the standard describes the design rules, the material properties, the production tolerances and the acceptance tests.
To insure stability, total bearing thickness should not exceed the smaller of l3, b3 or. Policy for archiving bridge design notes in txdots bridge inspection database management system. Ccl advanced solutions help create innovative bearings that anticipate. To model a different bearing layout, delete the links automatically created, then, outside. Bridge bearings are elements transmitting the loads from. These horizontal forces require that bearing stability be investigated. The bearings broke due to excessive lateral load at the inclined. The addition of a lowfriction sliding surface allows a standard laminated elastomeric bearing device to accommodate unlimited horizontal displacement without increasing the height of the bearing assembly. Loadmeasuring pot bearing with builtin load cell part i. Kinedyne manufactures a wide variety of expansion joints and high load bearing components for highway bridges including, but not limited to, the following. Pdf effect of change in radius of curvature in plan on bridge. That standard comprises numerous separate parts, relating to general rules, and rules for individual types of bearings or components of bearings. Situated in the heart of the west midlands, bridge bearings is the largest manufacturer of semiprecision bearings, for the materials handling industry, in the uk today. Bearing and girder movement was monitored on both bridges.
Movement could be thermal expansion or contraction, or movement from other sources such as seismic activity. Bridge bearings are used to transfer forces from the superstructure to the substructure, allowing the following types of movements of the superstructure. The elastomeric bearing pad and its role in bridge design. Kansas department of transportation bridge construction manual version 107 kdot bridge section 11. Bridge bearings types of bearings for bridge structures. The task of the bridge designer is to define a schedule of forces and. Bridge design bridge abutment design example to british. Similar with pot bearing, spherical bearing also can be divided into three types. 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. Different bridge bearings have different appearances, but all of them are in small size, which means they are smaller than bridge deck sometimes even the piers they sit on.
Design step 6 design of bearings prestressed concrete bridge design example task order dtfh6102t63032 63 elastomer grade is selected based on the temperature zone of the bridge location and by table s14. Steel bridge design handbook bearing design volume 15. Rocker and pin bearing should be considered when the bridge movement is adequately known and described, since such bearings can make rooms for both translational and. The extent of flat to vertical load is expanding because of the present pattern toward constant. This iricen publication is a result of the desire to fill the gap. A bridge bearing is a component of a bridge transmitting the loads received from the deck on to the substructure and to allow controlled movement due to temperature variation or seismic activity and thereby reduce the stresses involved. Bridge bearings trelleborg marine and infrastructure. The effect of resetting the original natural rubber bearings at the slaughter creek bridge was compared with the effect of replacing the rubber bearing with a neoprene bearing. 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. Reinforced elastomeric bearings are an often used type of bridge bearings and already been installed in many kinds of structures all over the world. Information on the attachment of bearings is given in gn 2. Steel bridge bearing design and detailing guidelines section 1 elastomeric bearings 1. The bridge modeler locates bearing links directly below the girder web.
Two levels of stability criteria, for normal conditions and for extraordinary temporary conditions, are. Bridge bearings, structural bearings, ptfe sliding bearings, rocker bearings, pot bearings, pin bearings, level sensors, detectors, indicators, point level switches. With extensive experience in bridge engineering, freyssinet is able to provide a onestopshop for the design, manufacture and installation of bridge bearings, from assessment and temporary works design through to supply and installation. Whether bearings are proprietary or fabricated, their design and manufacture must conform to en 37 ref 3. Information on bridge bearings is available in various technical literatures but it is scattered. Test methods for elastomeric bearings on bridges by y. Department of transportation federal highway administration by the. The required passage may be for a road, a railway, pedestrians, a canal or a pipeline. Bridge bearings introduction aashto defines a bearing as a structural device that transmits loads while facilitating translation andor rotation.
In addition, they are easily installed and maintenancefree. Van lund, washington state department of transportation the washington state department of transportation wsdot has removed and replaced nonfunctioning bridge bearings to extend the service lives of existing bridges. Due to liquefaction and ground movement, some piers moved and associated spans shifted on bearing supports. Bearings are designed and manufactured to transmit vertical and horizontal loads from the superstructure to the substructure, while allowing specific movements and rotations of the superstructure caused by wind or seismic effects, temperature variations, deck deflections, elastic shortening due to creep, shrinkage or posttensioning, etc. Inoperable roller nests and seismically vulnerable. Kinedyne incorporated, established in 1982, has been a leader in the bridge industry for over 30 years. It is noted that stability is a part of bridge bearing design, and that bearings must be designed and detailed to meet required vertical and horizotal load capacities. Pot bearings are often regarded as suitable for use when bridge bearing rotations are too large. A bridge is a manmade structure built to avoid physical obstacles without closing the way underneath such as a body of water, valley, or road. Rocker and pin bearing should be considered when the bridge movement is adequately known and described, since such bearings can make rooms for both translational and rotational movements in one direction only. Furthermore, if the horizontal shear force is greater than onefifth of the.
Jan 26, 2020 bridge bearings 2 types of bearings for a girder bridge published by bimlesh on january 26, 2020 january 26, 2020 the devices fixed on abutments and piers to allow for free expansion, contraction, and deflection of the bridge superstructure are known as bridge bearings. Fhwa bridge inspection manual section 9 bridge bearings 2012 instructor. Drew e gilstad, bridge bearings and stability in asce, new. Not applied to free abutment if sliding bearings are provided case 1 fixed abutment. Bridge decks supported by piers are susceptible to damage due to movement of the vehicle and heat expansion. Joint failure can lead to increased damage to bridge substructures including rust formation on metal bearings as well as increased spalling on precast beam ends, concrete abutments, and concrete piers. Laminated elastomeric bearings with known rated loads bearings to australian standard 5100. Examples of this sort of direction are axial ball and roller bearings. Overwrite options are located under brim bridge object abutments and bents. To prevent further bridge damage, joints are often repaired or replaced. Dec 18, 2019 user guide to bridge standard detail sheets section 9 bridge bearings ptfespherical sliding bearing details. Spherical bearing, also called spherical bridge bearing, is one type of bridge bearings with large rotation capacity. We pride ourselves on designing and fabricating the best solution for each project. D, pe retired pdh online pdh center 5272 meadow estates drive.
Bridge bearings, which are applied to support the upper structure of the railway bridge, should be designed to accommodate a high rotation angle that may be induced by wheel load since unlike. For stability, the total effective height of the rubber should not be higher than a quarter of. The purpose of a bearing is to allow controlled movement and thereby reduce the stresses involved. Dearen r ansrain federal high way administration july 2016.
Astm d4014 032018 standard specification for plain and. The purpose selected sealing systems of the elastomeric pad, are designed to resist extrusion of the elastomeric pad when under load. Pdhonline course c485 2 pdh fhwa bridge inspection manual section 9 bridge bearings 2012 instructor. In the last two decades, the rapid deterioration of bridge structures has become a serious technical and economical problem in many countries, including highly developed ones.
Since 2005 the european standard en 373 has applied to elastomeric bearings for architectural and civilengineering applications. Bridge bearings california department of transportation. Pot ptfe bearings are capable of bearing vertical load, horizontal forces and allows movement as well as rotation alongany horizontal axis. Bridge engineers today usually do not design bearings. This is typically made of a strong and pliable material such as neoprenea type of heavyduty industrial rubber. Bridge bearings are small integral parts of the entire bridge structure serving several purposes, such as connection, transfer of forces, allowing movements, force damping etc. Granor pot type structural bearings feature a circular elastomeric pad encapsulated inside a metal pot having a close fitting lid, which acts as a piston. The bridge deck is fixed in one corner and horizontal movements are controlled by the use of guided unidirectional bearings. However, bridge bearings could create more problems for the bridge structure than it solves if not properly understood, especially. Bridge bearing fuse systems home northeastern university. W, stability shall be investigated by interchanging l and w in eqs. 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 forces on both the superstructure and substructure due to constraint. Bridge flexibility is primarily achieved by a component called bridge elastomeric bearing pad.
Users may specify different girderbearing properties at each bent and abutment. Latest developments and applications for bridge bearings summary. This specification covers bearings, which consist of all elastomer or of alternate laminates of elastomer and steel, when the function of the bearings is to transfer loads or accommodate relative movement between a bridge superstructure and its supporting structure, or both. Bridge bearings and stability journal of structural. Trelleborg designs and manufactures elastomeric bridge bearings in accordance with this standard. The selection of the target reliability assumes a significant amount of redundancy in the foundation system is present, which is typical for pile groups containing at least five piles in the. Plain and laminated elastomeric bridge bearings are designated by hardness durometer, size, and configuration and, in the case of laminated bearings, by the thickness of the individual layers of elastomer and the size and position of any steel top plates. Nevertheless, there has been concern that bearings are being unnecessarily rejected because of noncom.
Our internal team of engineers and fabricators will work with you to design the right solution for your bridge project. User guide to bridge standard detail sheets, section 9. Bridge bearings support structures at a constant elevation, carrying forces from the superstructure into the substructure and allowing necessary superstructure motions to take place. It is noted that stability is a part of bridge bearing design, and that bearings must be designed and detailed to meet required vertical and horizotal load capacities, rotation limits, and anchor bolt clearances.
Design step 6 design of bearings prestressed concrete. The san franciscooakland bay bridge elastomeric bearing pad role of the elastomeric bearing pad. Taking advantages of the small size, all forces converge on a small point and to be transferred to the foundation through a very compact line. Sliding multidirectional ptfe spherical bearings allow polytetrafluoroethylene horizontal movements in any direction. This website and documents are provided for use by persons outside of the kansas department of transportation as information only.
Bridge bearing, as connection component, can provide a resting surface between bridge and bridge piers. Introduction elastomeric bearings introduced nearly 60 years ago, laminated steelelastomer bearing pads are now in. Both rocker and pin bearings are mainly employed in steel bridge structure. These include rockers, rollers, pins, pots, steel girder hangers, ptfeelastomeric, and elastomeric pads. Simple bridge bearing layout single span on pot bearings the arrangement above shows the layout for a simple single span structure with skew. Our bearing range includes steel and plastic housed bearings for all types of conveyor rollers as well as bearings for overhead conveyors which include crowded race, sintered iron caged and ribbon caged construction. A bridge bearing is a superstructure element that provides an interface between the. Depending on the area of application and country requirements maurer elastomeric bearings can be supplied in accordance with various standards, e. Bearing pads are either plain or reinforced with respect to the loads defined. Although many different types of bridge bearings have been used by the nysdot, elastomeric and multirotational bearings are the. Stage 4 completed structure once the deck has hardened, the steel bridge girders are composite with the deck and stability of the top flange is provided. And the purpose of bridge bearing is to transfer forces from the superstructure to the substructure or reduce the ground vibration to the superstructure.
A bridge bearing is a component of a bridge which typically provides a resting surface between bridge piers and the bridge deck. Elastomeric bridge bearings have generally performed satisfactorily under current aashto and state dot materialstest methods and requirements. Bearing design spread sheet based on aashto 16th edition. Elastomeric bridge bearing design design spreadsheet based on aashto 16th edition 1197 interim method a aashto lrfd. 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. General in the majority of steel bridges it is convenient to. Steel bridge bearings may be divided into three general types. Trbs second strategic highway research program shrp 2 report s2r19arw2.
Information on bridge articulation is given in gn 1. Bridge bearings technical knowledge base computers and. The architects of extensions must assure themselves that bridge bearings can transmit the highlevel heaps of current outlines. Bridge bearings 2 types of bearings for a girder bridge. This chapter also addresses corrosion protection measures. The material in this report will be of immediate interest to bridge designers and materials engineers. Therefore, bridge rehabilitation has also become a very essential factor sometimes. The loadmeasuring pot bearing with builtin load cell proposed in this study has been conceived as shown in. Bridge rehabilitation world scientific publishing company. Bridge bearing replacement transportation research board.
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