The simulation drives a virtual truck over the bridge. Free pdf printers are available from and pdf creator. Create an image file that is compatible with internet explorer. 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. Appendix a examples colorado department of transportation. Case studies that show three recent bridge bearing replace. More detailed design related to specific bridge types is covered in chapters 7, 8, and 9. A try different ways to support the deck of the test bed using the information provided. The obstructions may be river, valley, rail route or road way etc. A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts. Bridges are classified into so many types based on different criterias. These early concrete piles were the castinplace type. All bearings do, however, have at least the bearing or bearing surface. Laminated rubber bearings provide the simplest method of isolation and are most suitable for high frequency ground motions.
Piles can by classified on the basis of following characteristics, following are the types of piles. Expansion and contraction caused by temperature changes, shortening and creep caused by prestressing, deflections caused by live loads, and longitudinal forces. The discussions and examples in this chapter are based on a number of referenced specifications that were current at the time of publication. Pot bearings are special types of bearing pads for taking larger loads, translation and rotation in confined areas. The separator, which retains the balls or rollers, is also called the cage. It typically consists of a pin at the top that facilitates rotations, and a curved surface at the bottom that accommodates the translational movements. The most common bearing application is the ball bearing. A common form of modern bridge bearing is the elastomeric bridge bearing. Linear bearing types range from ball bearing cagesessentially bare cages holding balls that are often used as diepost bushingsto recirculating ball designs where the balls roll linearly along the shaft and then return to their starting points through channels on the nonshaft sides of the bearings.
The radial ball bearing is designed to accommodate primarily radial loads but the deep groove type will support bidirectional thrust loads up to 35% of. During running, the faces of the bearing pads are separated from the shaft collar by a thin oil. Several layers are placed on the bridge seat with the superstructure. Pot bearings are often regarded as suitable for use when bridge bearing rotations are too large.
In a tapered roller bearing, the center lines do not converge at a common point. The oldest form of bridge bearing is simply two plates resting on top of each other. Types of piles based on the mechanism of load transfer endpoint bearing piles. This article throws light upon the top seven types of bearings used under the bridges. Steel bridge bearings may be divided into three general types. A support with a f will have a bearing device that will resist longitudinal movements. The bridge designer will prohibit movement in some bearings and allow movement in others. Different types of bridges bridge and its components. The required passage may be for a road, a railway, pedestrians, a canal or a pipeline. Apr 23, 2015 bridge bearings until the middle of this century, the bearings used consisted of following types. Inspection and evaluation of bridge bearings topic 9. Aashto steel bridge bearing design and detailing guidelines 1st edition, g 9. Any of the mechanical bearings can be converted to uplift type.
In recent years considerable progress has been made in the mechanical design of the fixed and moving components. The rolling elements distinguish the two basic bearing types ball bearings and roller bearings. Bearings are made to order to conform to all relevant local and international regulations and standards. Possible causes of movement are thermal expansion and contraction, creep, shrinkage, or fatigue due to the properties of the material used for the bearing. Bridge bearings support structures at a constant elevation, carrying forces from the superstructure into the substructure and allowing necessary superstructure motions to take place.
The characteristics and uses of each type will be detailed in chapter four. Another type of bridge bearing is the mechanical bridge bearing. Bearing pads are either plain or reinforced with respect to the loads defined. Piles can by classified on the basis of following characteristics, following are the types of piles mechanism of load transfer also see.
Pin bearing a pin bearing is a type of fixed bearings that accommodates rotations through the use of a steel. The details are for steel reinforced elastomeric pads. The obstacle to be crossed may be a river, a road, railway or a valley. Rocker and pin bearings are primarily used in steel bridges. Bridge and structures detailing policy manual page i revision summary. Bridge bearings are used to transfer forces from the superstructure to the substructure, allowing the following types of movements of the superstructure. A bridge is structure which allows passage over an obstruction. A rocker bearing is a type of expansion bearing that comes in a great variety. A bridge bearing is a component of a bridge which typically provides a resting surface between bridge piers and the bridge deck. Aashto steel bridge bearing design and detailing guidelines three major types of bridge bearings are presented.
Ail machines necessarily employ them and all engineers must possess some knowledge of their design, construction, lubrication, adjustment. Bridge deck joints and deck joint seals introduction although often thought of as static, highway structures are continually in a state of motion. The superstructure must be raised to replace bridge bearings. The construction layout sheet in the plans will show the designers intent. Types of piles based on the mechanism of load transfer. Bridge bearings types of bearings for bridge structures. Bearings gives the supporting conditions to super structure. 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.
Bearing types and application design ball bearings. Although many different types of bridge bearings have been used by the nysdot, elastomeric and multirotational bearings are the. West point bridge designer is the official software used for the west point bridge design contest, which allows students to submit bridge designs for prizes. The primary function of elastomeric bearing pads is to provide a connection to control the interactions of loading and movements between parts of a structure, usually between superstructure and substructure. Aashto steel bridge bearing design and detailing guidelines. Bearings are important elements in large infrastructures such as bridges, heavy buildings and high rise buildings, ensuring load transfer, movement, rotation, vertical or horizontal restraints as required by the design at critical locations in a structure. 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. Bridge decks supported by piers are susceptible to damage due to vehicle movement and heat expansion. Elastomeric bearings for construction industry in neoprene and natural rubber compound. There are various types of bridges classified based on span, materials, types of bridge structures, functions, utility and position etc. Types of elastomeric bearing pads plain and laminated elastomeric bearings pads. The two basic types of bearing closures are shields and seals, both of which may be ordered as integral components of deep groove beahgs.
A bearing is ideally required to provide six degrees of freedom. Bearing is the component of bridge on which the girder in case of girder bridge, or solid slabin case of slab bridge rests. Bridge designs can be simulated in the software to test the load bearing quality of the bridge. File example 4 type ii bearing reinforced bearing with ptfe method b file example 5 expansion device strip seal 04 inch. Bridge bearings types of bearings for bridge structures and. It is proposed the student to achieve, test and comment on different means of holding the deck. Plain bearing, consisting of a shaft rotating in a hole. Rollingelement bearing, in which rolling elements placed between the turning and stationary races prevent sliding friction.
Although many different types of bridge bearings have been used. Pin bearing a pin bearing is a type of fixed bearings that accommodates rotations through the use of a steel translational movements are not allowed. 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. If a bedrock or rocklike material is present at a site within a reasonable depth, piles can be extended to the rock surface.
Bearings transfers loads from super structure to sub struc. 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. However, the span restriction for sliding bearing utilization can be disregarded when it is used in combination with other bearing types. In the years immediately preceding the turn of the twentieth century, several types of concrete piles were devised. 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. 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. Bearing types include no bearing required integral or continuous frametype bridge modern isolation bearings aashto 2010, guide specifications disktype. Types of elastomeric bearing pads construction rubber. Bridge rehabilitation an overview sciencedirect topics. Bearings, are antifriction devices, each having different antifriction characteristics. Classification of piles on the basis of load transfer. Ball bearing types permit smooth, lowfriction movement between two or more surfaces.
Ccl advanced solutions help create innovative bearings that anticipate. Sliding bearings rocker and pin bearings roller bearings elastomeric bearings curved bearings pot bearings disk bearings. In this stage, the noncomposite girder is at the bridge site, sitting on its bearing points, and it is carrying its selfweight plus the weight of the wet bridge deck. Expansion and contraction caused by temperature changes, shortening and creep caused by prestressing, deflections caused by. The submerged timber piles of this bridge, which were driven in 900 ad, were found in good condition and were reused. Ihe angu lar contact bearing design is not easily adaptable to integral closures. 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. Bridge lines, bridge fonts pdf, 267kb bridge font true type font format. Steel bridge design handbook bearing design volume 15. The designer must determine which bearing type is best suited to cost effectively accommodate the design. In general, there are two types of supports shown on plans, fixed f or expansion e. The same principles apply to all types of structure where forces are exerted. Bepona allows students to assemble five types of bridge.
The purpose of a bearing is to allow controlled movement and thereby reduce the stresses involved. Elastomeric bearings for construction industry in neoprene and natural rubber compound laminated rubber bearings provide the simplest method of isolation and are most suitable for high frequency ground motions. Main parts and types of bridges in civil engineering duration. The reader is cautioned to verify these requirements against the. In this case, the ultimate bearing capacity of the pile depends. Ball bearing types the three most commonly used types of ball bearings are the radial bearing, the angular contact bearing, and the double row ball bearing. There are several types of mechanical bridge bearing, such as the pinned bearing, which in turn includes specific types. The reader is cautioned to verify these requirements against the most recent.
Types of bridges based on span, materials, structures. This movement is either rotary shaft rotating within a mount or linear one surface moving along another. All closures serve the same purposes with varying effectiveness. Inoperable roller nests and seismically vulnerable steel rocker bearings with excessive tipping have been re moved and replaced to restore expansion capability. Fhwa bridge inspection manual section 9 bridge bearings. There are at least 6 common types of bearing, each of which operates on different principles. Bridge bearings until the middle of this century, the bearings used consisted of following types. Different types of bridges with pdf file engineering.
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