CA1100714A - High load bearing for bridges and similar structures - Google Patents

High load bearing for bridges and similar structures

Info

Publication number
CA1100714A
CA1100714A CA305,065A CA305065A CA1100714A CA 1100714 A CA1100714 A CA 1100714A CA 305065 A CA305065 A CA 305065A CA 1100714 A CA1100714 A CA 1100714A
Authority
CA
Canada
Prior art keywords
load bearing
elastomer pad
pad
plates
high load
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA305,065A
Other languages
French (fr)
Inventor
Stewart C. Watson
Edward R. Fyfe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Elastometal Ltd
Original Assignee
Elastometal Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Elastometal Ltd filed Critical Elastometal Ltd
Application granted granted Critical
Publication of CA1100714A publication Critical patent/CA1100714A/en
Expired legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E01CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01DCONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
    • E01D19/00Structural or constructional details of bridges
    • E01D19/04Bearings; Hinges
    • E01D19/041Elastomeric bearings

Abstract

ABSTRACT OF THE DISCLOSURE

A high load bearing for bridges and other structures comprising upper and lower plates and a load bearing elastomer pad between them. The pad has a concave periphery, and the bearing is provided with means preventing shearing between the upper and lower plates but permitting rotational movement between them. Means are provided which mechanically abut the elastomer pad to limit or prevent lateral movement of the upper and lower surfaces of the elastomer pad without preventing bulging of its periphery.

Description

~10~)7:t4 The present invention relates primarily to an im-provement in bearings of the type described and claimed in U.S. Patents 3,806,975 and 3,921,240. The bearings described in these patents are primarily intended for the support of the decks of bridges or piers and abutments wherein rotational and/or translational motion takes place between the bridge deck and the pier or abutment. However, the present invention also provides an improvement which is useful with bearings of somewhat similar general construction wherein there may be no rotation or trans-lational movement between the bridge deck and the pier or abutment.
The invention also is useful with bearings which support other structures such as buildings. The principal objective of the invention is to assure that the bearing will have the capabilility of sustaining very heavy loads and that the load carrying capability will be stabilized.

In bearings of the aforesaid type, an elastomeric pad, generally 1/4 to 5 inches thick is fitted between two flat plates which in turn are secured between the bridge deck or some other structure and the pier, abutment or some other foundation. In the type of bearings described in the aforesaid patents, a third plate is mounted for sliding movement relative to one of the plates and anchored to the structure or the foundation to accommodate trans-lational movement, and means are provided to minimize shearing strains in the elastomer without interfering with necessary rota-tion between the first and second plates and compression ofthe elastomer by the weight of the structure. The preferred type of elastomer pad is circular, and the lateral edge of the pad preferably is concave. In practice, the elastomer pads which have been used in this type of bearing have been biconical (i.e., they resemble a pair of conical sections, one inverted over the other).
Variations have been encountered in the load capa-, . .
bilities of the elastomer pad. This is evidenced by the load-deflection curve for the bearings wherein the deflection of a bearing under load is greater in some instances than in others. It now has been discovered that these variations can be attributed to variations in the bonding of the elastomer pad to the aforesaid plates above and below it, which is believed to have allowed the upper and lower surfaces of the biconical pad to spread laterally under load, to some extent irreversably. The present invention provides a structural means for preventing lateral spreading of the outer surfaces of the elastomer pad and therefore maximizing and stabilizing the load carrying capability of the bearings.
In a preferred form the invention also provides a safety element which protects the bearing pad from the hazard of overload and from separation from the aforesaid plates during rotation. Briefly, the structural means comprises means secured to the plate which provides a mechanical interlock with the elastomer pad so as to exert a force opposed to lateral growth of the upper and lower surfaces of the biconical or similar pad when it is compressed.
The invention will be better understood by reference to the following detailed description of preferred embodiments, reference being made to the drawing, in which:

11~0714 FIGURE l is a cross section through a preferred form of the new bearing;
- FIGURE 2 is a plan view of a plate used in the bearing of FIGURE l;
FIGURE 3 is a side elevation of the bearing pad of the bearing of FIGURE 1, when partly compressed;
FIGURE 4 is a side elevation of the bearing pad of the bearing of FIGURE l, when further compressed; and FIGURES 5-10 are cross sections through the bearing pad and ac'joining plates of other embodiments of the bearing of the present invention.
As shown in Figure 1, the bearing comprises three steel components, a square .op plate, a square middle plate
2 and a base plate 3. A circular bearing pad 4 is positioned ( 15 between the middle plate 2 and the base plate 3 and a low friction plastic sheet 5 is positioned in a recess 6 in the top of middle plate 2 to r`educe friction between middle plate 2 and top plate 1. The top plate 1 and the base plate 3 are fitted with concrete anchors 7 and 7' to secure them respectively to a bridge pier 8 and a bridge deck 9 although it will be understood that the bearings can be used in other kinds of constructio~.
The top plate l is provided with depending side plates lO and il which extend along opposite sides of the middle plate 2 to sub-stantially confine relative sliding movement between the bridge deck 9 and the pier8 to a single direction. However, it will be understood that other arrangements can be used, for example, to allow sliding movement in all directions, by omitting plates 10 and 11 or to substantially prevent sliding move~ent in all directions, depending upon the requirements of the structure.

The bearing is equipped with a pin 12, which is integral with the base plate 3 and which is engaged in a cylindrical collar 13 as described in U.S. Patents 3,306,975 and 3,921,240 in connection with Figure 3 thereof.
The bearing pad 4 is made from polyurethane elastomer, preferably 85 to 95 durometer, Shore A and is of biconical shape. The dimensions of the pad 4 depend on the weight the pad is expected to support, but typically the exte-nal diameter is 4 to 60 inches and the diameter at the midpoint 14 is typically 1/8 to 2 inches less than the diameter of the pad.
In one for~ of the ~resent invention, the ~iddle plate 2 is provided with a depending circular ring 15 which extends around the bearing pad, but whose internal diameter is slightly larger than the initial diameter of the bearing pad 4.
Preferably, a clearance of 1/32 to 3/8 inch is provided. Simi-larly, the base plate 3 is provided with a raised ring 16 of the same diameter and it allows the same clearance.

The arrangement is such that, as initially assem-bled, the bearing pad does not contact either of the rings lS
and 16. However, as the bearing is compressed by the weight of the structure, two phenomena are observed. First, as illus-trated in FIGURF 3, the tapered sides of the pad bulge outwardly and towards each other. Ultimately, if the bearing is compressed sufficiently, the tapered sides of the pad 4 bulge outwardly ~o the .

: , :

` 11~)0714 extent that they contact the rings 15 and 16. However, the bearings are designed so that this does not occur at the design load. Thus the ring provides a safety factor which comes into effect if the bearing is overloaded. At that stage the shape S factor of the pad is increased and it is substantially prevented from undergoing further compression.
The second phenomenon which is observed is that the diameter of the bearing pad 4 may increase slightly on its top and bottom surfaces, as described above, but growth is limited by the rings 15 and 16.
A third phenomenon is observed if the bearing is rotated or tilted. In this situation, the bearing pad is compressed more on one side than on the other side. When this occurs, the outwardly bulging tapered sides may contact the rings 15 and 16 in the area of greatest compression. When that occurs, further compression in that area is restricted in effect by changing the shape factor of the pad.
A further advantage of the invention follows from this arrangement. Because overcompression during tilting is avoided, it is possible to use relatively softer elastomer than otherwise would be possible. During rotational movements, soft elastomers can stretch a little, if needed, in the area opposite the compressed areas, and therefore, avoid separation from the plates 2 and 3, which otherwise might occur. As a result, the bearings can be rated for greater rotational movement than otherwise might be allowed.

11~)(~714 The overall effect of the invention is to increase the rated loadings of the bearings. For example, it is presently believed that bearing pads which were rated at 2500 psi can now be rated at 3~00 psi.

Further improvements in the bearings can be provided by other means which reduce the growth of the upper and lower surfaces of the pad 4. This is provided by a variety of mechani-cal interlock arrangements which provide an internally facing vertical or inclined surface of the middle plate 2 and/or the base plate 3 which abuts an outwardl~ facing vertical or inclined surface of the bearing pad 4 internally of the perimeter of the bearing pad. Several forms of abutting surfaces are illustrated in Figures 5-10. ~
Thus in Figure 5, metal rings 120 and 121 are fastened to the lower surface of plate 102 and the upper surface of plate 103. The metal rings 120 and 121 are formed with grooves 122 and 123 on their lower and upper surfaces respectively. The bearing pad 104 ls forced into the grooves 122 and 123, thereby providing a mechanical interlock. In Figure 6 there are rings 220 and 221 secured to the lower surface of plate 202 and the upper surface of plate 203 respectively. These metal rings 220 and 221 are formed with ribs 222 and 223 on their lower and upper surfaces respectively which press into the bearing pad 204. Therefore, a mechanical interlock is provided. In Figure 7, there are circular grooves 320 and 321 formed in the lower and upper surfaces respectively of the plates 302 and 303. The bearing pad 304 is pressed into these grooves and therefore a mechanical interlock is achieved. In Figure 8, there are circular ribs 42Q extending downwardly ~rom the lower surface of plate 402 and there is a circular groove 421 in the upper surface of lower plate 403. The ring 420 presses into the elastomer pad 404 and the pad is pressed into the groove 421. Therefore a mechanical interlock is accomplished. In Figure 9, there are circular rings 520 and 521 extending downwardly and upwardly respectively from the plates 502 and 503. The rings 520 and 521 press into the bearing pad 504 to provide a mechanical interlock. Figure 10 is quite similar to Figure 9 except that in this case there are three rings 620, 620' and 620" extending down from the lower surface of the plate 602. Similarly, rings 621, 621' and 621" extend upwardly from the upper surface of plate 603.
These rings press into the elastomeric bearing pad 604 to cause a mechanical interlock.

,.

Claims (9)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A high load bearing for bridges and similar structures comprising upper and lower plates, a load bearing elastomer pad between said plates, said elastomer pad having a groove extending around its periphery, a cooperating bearing member constructed and arranged to substantially prevent shearing movement between said plates but permitting rotational movement between said plates, and means mechanically abutting said load bearing elastomer pad to at least limit lateral expansion of the upper and lower surfaces of said elastomer pad under load without preventing bulging of said periphery.
2. A high load bearing as set forth in claim 1 in which said mechanically abutting means comprises a projection from one of said plates into a groove in one of said surfaces of said load bearing elastomer pad.
3. A high load bearing as set forth in claim 1 in which said mechanically abutting means comprises a projection from one of said surfaces of said load bearing elastomer pad into a groove in one of said plates.
4. A high load bearing as set forth in claim 3 in which said mechanically abutting means comprises means projecting from said plates adjacent the periphery of said load bearing elastomer pad.
5. A high load bearing as set forth in claim 4 in which a lateral clearance is provided between said surface of said load bearing elastomer pad and said projecting means when said bearing is not under load, whereby said load bearing elastomer pad is permitted limited lateral expansion before abutting said projecting means.
6. A high load bearing as set forth in claim 5 in which said lateral clearance is 1/32 to 3/8 inch.
7. A high load bearing as set forth in claim 5 in which said load bearing elastomer pad and said projecting means are circular.
8. A high load bearing as set forth in claim 5 in which said load bearing elastomer pad is biconical.
9. A high load bearing as set forth in claim 1 wherein said peripheral groove extends from the upper surface to the lower surface of said load bearing elastomer pad.
CA305,065A 1977-07-05 1978-06-08 High load bearing for bridges and similar structures Expired CA1100714A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US81247477A 1977-07-05 1977-07-05
US812,474 1977-07-05

Publications (1)

Publication Number Publication Date
CA1100714A true CA1100714A (en) 1981-05-12

Family

ID=25209669

Family Applications (1)

Application Number Title Priority Date Filing Date
CA305,065A Expired CA1100714A (en) 1977-07-05 1978-06-08 High load bearing for bridges and similar structures

Country Status (14)

Country Link
JP (2) JPS5417447A (en)
AU (1) AU516757B2 (en)
BR (1) BR7803576A (en)
CA (1) CA1100714A (en)
CH (1) CH630682A5 (en)
DE (1) DE2825606A1 (en)
ES (1) ES470268A1 (en)
FR (1) FR2396919A1 (en)
GB (1) GB1604125A (en)
NO (1) NO782244L (en)
NZ (1) NZ187434A (en)
PH (1) PH16573A (en)
SE (1) SE438514B (en)
ZA (1) ZA782235B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4617769A (en) * 1981-11-18 1986-10-21 Fyfe Edward R Aseismic bearing for bridge structures

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6132205U (en) * 1984-07-26 1986-02-26 ニッタ株式会社 Cross member support pad in expansion joint equipment
DE3616388C1 (en) * 1986-05-15 1987-03-05 Dyckerhoff & Widmann Ag Elastic deformation sliding bearing
DE4138708C2 (en) * 1991-11-26 2000-11-23 Blohm & Voss Ind Gmbh Arrangement for the elastic mounting of a combined pressure and support bearing, in particular for a ship propulsion system
JP2007291676A (en) * 2006-04-24 2007-11-08 Kaimon:Kk Rubber-sealed fixing and bearing apparatus for structure
JP5082785B2 (en) * 2007-11-13 2012-11-28 横浜ゴム株式会社 Sliding rubber bearing device
JP2012012765A (en) * 2010-06-29 2012-01-19 Kawakin Core-Tech Co Ltd Fixed bearing

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH445957A (en) * 1966-12-16 1967-10-31 Grube Ludwig Height-adjustable, elastic bearing foot for machines and apparatus of all kinds
DE1806628A1 (en) * 1968-11-02 1970-05-21 Continental Gummi Werke Ag Tilting bearings for buildings
US3806975A (en) * 1970-04-13 1974-04-30 Elastometal Ltd Structural bearings
AT327271B (en) * 1970-12-24 1976-01-26 Kober Ag TIPPER FOR BRIDGES OR AHNL. STRUCTURES
US3921240A (en) * 1971-04-27 1975-11-25 Elastometal Ltd Structural bearings
DE2237237C2 (en) * 1972-07-28 1974-01-03 Blt-Brueckenlagertechnik Gmbh, 5657 Haan Plain bearings for bridges or similar structures

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4617769A (en) * 1981-11-18 1986-10-21 Fyfe Edward R Aseismic bearing for bridge structures

Also Published As

Publication number Publication date
AU3680278A (en) 1979-12-06
NO782244L (en) 1979-01-08
FR2396919A1 (en) 1979-02-02
CH630682A5 (en) 1982-06-30
PH16573A (en) 1983-11-22
NZ187434A (en) 1982-05-31
GB1604125A (en) 1981-12-02
BR7803576A (en) 1979-04-17
JPS5417447A (en) 1979-02-08
JPS62125115U (en) 1987-08-08
ES470268A1 (en) 1979-02-16
AU516757B2 (en) 1981-06-18
SE7805330L (en) 1979-01-06
FR2396919B1 (en) 1984-04-20
ZA782235B (en) 1979-12-27
DE2825606A1 (en) 1979-01-18
SE438514B (en) 1985-04-22

Similar Documents

Publication Publication Date Title
US4187573A (en) High load bearing for bridges and similar structures
JP3467513B2 (en) Seismic isolation bearing with ball inside cone
CA1178303A (en) Aseismic bearing for bridge structures
CA1100714A (en) High load bearing for bridges and similar structures
JP2002038418A (en) Function separation type bridge support device
KR101003775B1 (en) Bridge bearing
CN215947865U (en) Large-displacement tensile bridge support for cable-stayed bridge
JP2020190320A (en) Sliding base isolation bearing structure
KR20130085629A (en) Structural bearing having attachment devices for sliding materials
KR100489577B1 (en) Level adjusting bearing for bridge
CN113403938A (en) Large-displacement tensile bridge support for cable-stayed bridge
KR100206637B1 (en) Pot bearing
KR200201065Y1 (en) Pot bearing with a device preventing removement of slab
KR100877836B1 (en) Pot bearing
JPH0487Y2 (en)
KR20070090053A (en) Bridge bearing
KR200272144Y1 (en) Half cylinder type bridge bearing
JPH03411Y2 (en)
KR102250263B1 (en) Temporary Supporting System of Structural Bearing for Continuation Construction
KR200181652Y1 (en) Elastic prop for bridge shoe
KR200241526Y1 (en) Elastomeric bearing combined with slip resistance stopper
KR102583618B1 (en) Rubber Bridge bearing including elastic pads with improved uniformity of product characteristics and maintaining a gap between rubber and steel plates
CN211285231U (en) Limiting device
SU1723264A1 (en) Earthquake-proof building and structure support construction
CN220414520U (en) Friction shock insulation support and shock insulation system

Legal Events

Date Code Title Description
MKEX Expiry