Elastomeric bearing pad, can be classified into plain elastomeric bearing, laminated bearing pad and ptfe sliding elastomeric bearing. Maurer elastomeric bearings are available made of natural or chloroprene rubber from inhouse production and mixture. The most important properties of elastomeric bearings are the shear ductility and high vertical stiffness in compression. Bridge bearings support structures at a constant elevation, carrying forces from the superstructure into the substructure and allowing necessary superstructure motions to take place. Trelleborg designs and manufactures elastomeric bridge bearings in accordance with this standard. Reinforced elastomeric bearings are an often used type of bridge bearings and already been installed in many kinds of structures all over the world. Elastomeric bearings are designed to accommodate three types of movement. They cater for vertical load where movement is controlled by shear deflection and rotation is by angular deformation.
Maurer elastomeric bearings maurer elastomeric bearings are available in natural or chloroprene rubber with steel reinforcement plates. Department of transportation federal highway administration by the center for transportation. This paper presents a discussion of the rationale for the use of elastomeric bearings for steel trapezoidal box girders, a historical overview of bridge bearing systems in texas, and the. Rotation trelleborg bearings are manufactured from natural rubber compounds chloroprene rubber compounds also available to meet a wide range of international standards and design guides including, as, bs, astm, aashto, naasra.
For bridges with the same characteristics size, type and the same loading conditions, many different sizes of elastomeric bearings can be designed. This report deals with phase one of txdot project 4 behavior of elastomeric bearings. Elastomeric bearings goodco ztech elastomeric bearings are fabricated of natural rubber or neoprene. The taper can be accomplished by using a tapered steel plate fig. Inspection, condition evaluation and replacement of. 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. Elastomeric bridge bearings bridge bearings support structures at a constant elevation, carrying forces from the superstructure into the substructure and allowing necessary superstructure motions to take place. Elastomeric bearings for steel trapezoidal box girder bridges. Inspection and evaluation of bridge bearings topic 9. Besides the functional requirements, the standard describes the design rules, the material properties, the production tolerances and the acceptance tests. The same principles apply to all types of structure where forces are exerted. The plan shall detail the inspection and testing proposed to insure the elastomeric bearings comply with. The overall objectives of that project are 1 to recommend procedures for designing elastomeric bearings used by txdot and 2 to recommend practical guidelines and procedures for inspecting existing and future elastomeric bearings. Since 2005 the european standard en 373 has applied to elastomeric bearings for architectural and civilengineering applications.
Elastomeric bridge bearings are designed to transform the movement and rotation of bridge structure into elasticity and minimizes the secondary stress generated in the bridge because of the layered rubber sheets reinforced by metal plates. The goal of this study is to study the condition of bearings which are. Elastomeric bridge bearings have generally performed satisfactorily under current aashto and state dot materialstest. Designed and sized to meet the needs of your structure, these bearings are rigid enough to transmit the necessary loads and flexible enough to permit the rotation and movement required by the structure. Elastomeric bearings for bridge structures it consists of elastomer manufactured from synthetic or natural rubber and can take both translation and rotation movements through elastomer deformation. Elastomeric bridge bearings, bearing pads, neoprene. Inspection of bridge bearings birm ced engineering. This includes pot bearings but does not hidden elastomeric or other type of bearings ea of bearing for each of the condition states, report the estimated quantity in each. The material in this report will be of immediate interest to bridge designers and materials engineers. The designer must determine which bearing type is best suited to cost effectively accommodate the design. Becker research report number 45 research project 04 elastomeric bearings conducted for the texas department of transportation in cooperation with the u. Traditionally, bridge bearings supporting steel trapezoidal box girder a. The state of maryland is now working to unify the design of elastomeric bearings.
All bearings are provided as standard in 60irhd natural rubber which encapsulates several steel and rubber layers. Compared to other types of bearings, they are easy to install, have a long life expectancy 100 years plus and are maintenance free. Tetron disc pot bearings designed and manufactured to en37. Elastomeric bridge bearings page 3 of 4 quality control by the manufacturer. The required design input at the strength limit state is shear force. Elastomeric bearings page 3 of 4 submittal for testing and approval a. Department of transportation federal highway administration by the. Although many different types of bridge bearings have been used by the nysdot, elastomeric and multirotational bearings are the. This paper presents the results of an inspection campaign as well as condition evaluation and replacement of more than elastomeric bridge bearings. Condition state descriptions condition state description. This is typically accomplished through the used of a tapered steel top plate.
Trelleborg designs and manufactures elastomeric bridge bearings in accordance with. Around this makeup a rubber cover encapsulates the bearing. Designed for use in bridge and building construction under precast concrete beams, steel beam supports and other support points. Installation elastomeric bearings pads based on aashto. En 373 has applied to elastomeric bearings for architectural and civilengineering applications.
These bearings are designed to accommodate vertical, longitudinal, horizontal and transverse loads. 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. Elastomeric bridge bearings pads manufacturers in india. C of the mdot bdm addresses the design of elastomeric bearings and specifies that steelreinforced elastomeric bearings are to be designed using method a. Freyssinet supplies both mechanical and elastomeric bridge bearings, designed by an inhouse design team and manufactured in its factory to the quality standard bs en iso 9001. For the last 50 years, maryland has used elastomeric bearings for concrete bridge structures. Figure 1 steelreinforced elastomeric bearings, sreb, and installation in bridge support figure 2 shows the three different possible deformation of the reb. Nonreinforced elastomeric bearing, solid blocks of rubber without reinforced layers, is widely used for.
These include rockers, rollers, pins, pots, steel girder hangers, ptfe elastomeric, and elastomeric pads. The ability of elastomer to carry large vertical loads is because of reinforcement provision that prevents lateral bulging of elastomer. These bearings are designed to accommodate vertical, longitudinal, horizontal and transverse loads movements and rotation. Scope before elastomeric bearings may be used for a department project, the manufacturer shall provide documentation that hisher product meets the requirements as specified in the standard specifications for road and bridge construction section 1083. Introduction elastomeric bearings introduced nearly 60 years ago, laminated steelelastomer bearing pads are now in service in tens of thousands of bridges and similar structures throughout the world.
Astm d4014 032018 standard specification for plain and. Steel bridge bearings may be divided into three general types. The information included is intended to permit efficient fabrication, installation, and maintenance of these bearings. Steel bridge design handbook bearing design volume 15. These items are then vulcanised to create a compact maintenance free bearing. Bridge bearings elastomeric bridge bearing manufacturer. Although standard sizes are shown within the literature bespoke bearings can be produced upon request. The element defines only those bridge bearings that are enclosed so they are not open for detailed inspection. Elastomeric bearings for further information download our pdf on maurer elastomeric bearings click here. Spherical bearings for further information download our pdf on maurer spherical bearings click here pot bearings. Bearings with sliding surface laminated elastomeric bearings can be fitted with a sliding surface comprising a ptfe polytetrafluoroethylene sheet dipped in the elastomer of the bearing or notched in the top thick outer plate and a sliding plate provided with an austenitic steel sheet for decks requiring significant movement. Elastomeric bridge bearings resist vertical load and provide horizontal movements and rotations. These include rockers, rollers, pins, pots, steel girder hangers, ptfeelastomeric, and elastomeric pads.
Design alternativeselastomeric bearings tapered bearings can be provided. Ekspan laminated elastomeric bearings are produced to the latest eurocode en373. Installation elastomeric bearings pads based on aashto, bsc and din regulations a. Depending on the area of application and country requirements maurer elastomeric bearings can be supplied in accordance with various standards, e. Honel bearings are manufactured from natural rubber compounds chloroprene rubber compounds also available to meet a wide range of international standards and design guides including, as, bs, astm, aashto, naasra. Elastomeric bridge bearings have generally performed satisfactorily under current aashto and state dot materialstest methods and requirements. These bearings are manufactured using high grade materials with the aid of contemporary techniques at our. Bridge bearings support structures at a constant elevation, carrying forces from the superstructure into the.
Laminated elastomeric bearings consist of natural rubber layers separated by steel plates. Special loadings can sometimes be met by inclined mounting of bearings. Bridge bearings types of bearings for bridge structures and. Ccl advanced solutions help create innovative bearings that anticipate. There are several different similar types of bridge bearings that include neoprene bearing pads, neoprene bridge bearings, laminated elastomeric bearings and seismic isolators, which are all generally referred to as bridge bearing pads in the construction industry they are designed and manufactured. We provide high quality elastomeric bridge bearings, also called neoprene bridge bearings, and elastomeric bearings. Bridge bearings introduction aashto defines a bearing as a structural device that transmits loads while facilitating translation andor rotation.
The three primary functions of a bridge bearing are. Steel bridge bearing design and detailing guidelines section 1 elastomeric bearings 1. They support vertical loads with minimal compression, allow expansion and contraction of. Elastomeric bearings can absorb horizontal movements in every direction and rotational movements around every axis through elastic layers deformation. Depending on their type, they can also transmit external forces by means of guides or restraints. When the rubber pad undergoes a displacement, it generates an elastic force proportional to the displacement. Bridge bearings trelleborg marine and infrastructure. Spherical bearings for further information download our pdf on maurer spherical bearings click here. An elastomeric bridge bearing is a commonly used modern bridge bearing.
July 2019 276 the required design input for the design of an elastomeric bearing at the service limit state is dead load, live load plus dynamic load allowance, minimum vertical force due to permanent load, and design translation. Elastomeric bearings would generally be positioned next to the uniguide bearing to take up the vertical load. Elastomeric bridge bearings, bearing pads, neoprene bearings. Erection place bearings at their proper locations before erecting the superstructure supported by the bearni gs. The function of the bearing is to safely accommodate the various movements and rotations as well as supporting the weight of the structure and to transmit the load through to the structures foundation. Installpier tops install pier tops horizontal at the correct elevation with a plus or minus tolerance of zero. Consisting of a steel top plate with a stainless steel facing upper component bearing on a preformed fabric pad bonded to a layer of polytetrafluoroethylene ptfe material lower component, with or without special components steel guide bars and bottom plate. Trelleborg elastomeric bearings are designed to accommodate three types of movement. Goodco ztech elastomeric bearings are fabricated of natural rubber or neoprene. This bearing is the connection between a structure and its support, and should make the following possible through elastic deformation. Trelleborg infrastructure designs and manufactures elastomeric bridge bearings in. Department of transportation federal highway administration by the center for transportation research.
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