The layout of each track must be completely parallel on one side of the bridge versus the other. Ccl advanced solutions help create innovative bearings that anticipate. The same principles apply to all types of structure where forces are exerted. The required passage may be for a road, a railway, pedestrians, a canal or a pipeline. Snapon pullers the abcs of selecting the right puller. Flat land bearings will carry only 1020 % of the load of other thru st bearing types, because flat parallel surfaces do not provide pumping acti on needed to build oil fil m pressu re in a. In a tapered roller bearing, the center lines do not converge at a common point. Bridge types tr sstruss system of straight, connected elements used to resist load commonly seen as through truss or deck truss popular in 19th and early 20th centuries constructed of wrougg,ht iron, steel, or timber. Function of bearings for bridges bridge bearings are used to transfer forces from the superstructure to the substructure, allowing the following. There are several different types of bridge bearings which are used depending on a number.
A drawing showing the bearing layout should include the following. Steel bridge bearing selection and design guide steel building. Main parts and types of bridges in civil engineering duration. 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 a range of different bearing types is available. The bridge designer will prohibit movement in some bearings and allow movement in others. This movement is either rotary shaft rotating within a mount or linear one surface moving along another. Bearings are elements transferring vertical loads from.
Wisdot bridge manual chapter 27 bearings july 2019 273 27. Trbs second strategic highway research program shrp 2 report s2r19arw2. Possible causes of movement are thermal expansion and contraction, creep, shrinkage, or fatigue due to the properties of the material used for the bearing. Bearings gives the supporting conditions to super structure. Heavy weight hinges should always be used on heavy doors and doors where high frequency is expected. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
The hinged bearing is composed of one curved top plate over a flat bottom plate with a pin at the centre which allow rotation but prevent translation. The obstacle to be crossed may be a river, a road, railway or a valley. Bearing pads are either plain or reinforced with respect to the loads defined. Several layers are placed on the bridge seat with the superstructure.
Similar to rocker and roller bearings, two types of plate bearings are used, viz. Pot bearings are often regarded as suitable for use when bridge bearing rotations are too large. Bearings, are antifriction devices, each having different antifriction characteristics. Steel bridge bearings may be divided into three general types. The superstructure must be raised to replace bridge bearings. 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.
However, the span restriction for sliding bearing utilization can be disregarded when it is used in combination with other bearing types. When the direction of the load is parallel to the shaft. If the specific bearing type is not known, reference the index in the back of the guide for the page number where the bearing is listed. The construction layout sheet in the plans will show the designers intent. The designer must determine which bearing type is best suited to cost effectively accommodate the design. The most common bearing application is the ball bearing.
The separator, which retains the balls or rollers, is also called the cage. Bepona allows students to assemble five types of bridge. The bridge superstructure consists of the components that actually span the obstacle the bridge is intended to cross and includes the following. Section 2 special design requirements for different bearing types. Requirements, evaluation of bearing types and bearing selection and design. A more detailed analysis of bearing design is provided in the steel bridge bearing design guide and commentary in part ii of this document. Bearing types and application design ball bearings. Ball bearing types permit smooth, lowfriction movement between two or more surfaces. Bridge lines, bridge fonts pdf, 267kb bridge font true type font format. Wisdot bridge manual chapter 27 bearings wisconsin dot. What links here related changes upload file special pages permanent link page information wikidata item cite this page. 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. Types of bearings geometer discusses the various types of bearing in common use and gives examples of their use b earings are the means by which shafts are located, enabled to carry loads and transmit power. Expansion and contraction caused by temperature changes, shortening and creep caused by prestressing, deflections caused by.
In the course of the past two centuries bridge bearings evolved as parts of. Sci p185 guidance notes on best practice in steel bridge construction. Generic standard abutment plans were developed for which the engineer can provide necessary bridge site information in the spaces provided. A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts. Ball and roller bearings cad data of model numbers given in the catalog is available as an electronic catalog. The maximum allowable compressive stress on the bearing is a function of the shear modulus. A bridge bearing is a component of a bridge which typically provides a resting surface between bridge piers and the bridge deck. Although many different types of bridge bearings have been used. Bridge bearings types of bearings for bridge structures and details.
In general, there are two types of supports shown on plans, fixed f or expansion e. Bearings transfers loads from super structure to sub struc. Ail machines necessarily employ them and all engineers must possess some knowledge of their design, construction, lubrication, adjustment. Rocker and pin bearings for bridge structures rocker is an expansion bearing composed of curved surface at the bottom, which accommodate translational movement and a pin at the top makes room for rotation. Piles can by classified on the basis of following characteristics, following are the types of piles mechanism of load transfer also see. Bearings, their types and application linkedin slideshare. Bridge bearings indian association of structural engineers. Department of transportation that provide values for estimating pile friction and end bearing for different combinations of soils and pile types are also included. Pdf management system for road bridge structural bearings. A roving bridge, changeline bridge or turnover bridge is a bridg e over a canal constructed to allow a horse towing a boat to cross the canal wh en the towpath changes sides. Inspection and evaluation of bridge bearings topic 9. Bar type puller with bearing separator bar type with side rods threaded into.
Bridge bearings support structures at a constant elevation, carrying forces from the superstructure into the substructure and allowing necessary superstructure motions to take place. Pin bearing a pin bearing is a type of fixed bearings that accommodates rotations through the use of a steel. Bearing adaptors with slide hammer puller cj127a, cj128a, and cj7 bearing adaptors with cj973a slide hammer should be used in this application. Bridge deck joints and deck joint seals introduction although often thought of as static, highway structures are continually in a state of motion. Bearings in this catalog are arranged by bearing type, with a size andor numerical listing. Development of abutment design standards for local bridge. December 2, 2015 reduced type iii bearing load capacity. When the direction of the load weight being moved is at right angles to the shaft, it is called a radial load. Types of cages differ according to way they are manufactured, and include pressed, machined and formed cages. Steel bridge design handbook bearing design volume 15.
A try different ways to support the deck of the test bed using the information provided. 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. The most common elastomers used for bridge bearings are neoprene and natural rubber. Bridge bearings until the middle of this century, the bearings used consisted of following types. Use antifriction bearing hinges on doors equipped with closers.
Types of piles based on the mechanism of load transfer endpoint bearing piles. For an existing bridge without integral end bents, the design criteria shown in figure 4092a shall be used in evaluating the conversion to an integralendbent structure. For example, this means when bridge traffic runs east and west, the north and south track plates must be completely parallel. Bridge bearings types of bearings for bridge structures. Bridge bearings are used to transfer forces from the superstructure to the substructure, allowing the following types of movements of the superstructure.
Pulling can be done with bridge, bar type yokes, or slide hammers. The rolling elements distinguish the two basic bearing types ball bearings and roller bearings. Pot bearings are special types of bearing pads for taking larger loads, translation and rotation in confined areas. It is proposed the student to achieve, test and comment on different means of holding the deck. The purpose of a bearing is to allow controlled movement and thereby reduce the stresses involved. Although many different types of bridge bearings have been used by the nysdot, elastomeric and multirotational bearings are the. Bearing is the component of bridge on which the girder in case of girder bridge, or solid slabin case of slab bridge rests. All bearings do, however, have at least the bearing or bearing surface. Bridge and structures detailing policy manual page i revision summary.