U.S. patent number 3,880,540 [Application Number 05/358,059] was granted by the patent office on 1975-04-29 for modular expansion joint.
This patent grant is currently assigned to The D. S. Brown Company. Invention is credited to Delmont D. Brown, Michael C. Rizza.
United States Patent |
3,880,540 |
Rizza , et al. |
April 29, 1975 |
Modular expansion joint
Abstract
Modular expansion joints made from aluminum extrusions providing
longitudinal frames and longitudinal rails. The rails have an
I-beam-like structure with upwardly opening channels respectively
receiving and interlocking therein deformable beads on the lower
surface of an elastomer tread with hollow, V-sections deforming
downwardly as the joint width becomes narrow. The elastomer tread
completely covers and spans the joint. The longitudinal rails are
supported by solid load-bearing beams having a greater width than
depth, and coil springs are interposed between contiguous
rails.
Inventors: |
Rizza; Michael C. (Walnut
Creek, CA), Brown; Delmont D. (North Baltimore, OH) |
Assignee: |
The D. S. Brown Company (North
Baltimore, OH)
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Family
ID: |
26820006 |
Appl.
No.: |
05/358,059 |
Filed: |
May 7, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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121957 |
Feb 8, 1971 |
3732021 |
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Current U.S.
Class: |
404/69 |
Current CPC
Class: |
E01D
19/062 (20130101) |
Current International
Class: |
E01D
19/06 (20060101); E01D 19/00 (20060101); E01c
011/02 () |
Field of
Search: |
;404/47,48,60,68,69,50,51,47 ;14/16 ;52/396,403 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Byers, Jr.; Nile C.
Attorney, Agent or Firm: Johnston, Keil, Thompson &
Shurtleff
Parent Case Text
RELATED APPLICATION
This application is a continuation-in-part of our application Ser.
No. 121,957, filed Mar. 8, 1971 now U.S. Pat. No. 3,732,021.
Claims
The invention is hereby claimed as follows:
1. A shallow modular joint structure useful for spanning joints
comprising a pair of elongated longitudinal frames adapted to be
mounted at the respective edges of the joint, a plurality of
elongated, longitudinal rails spanning the joint in parallel,
spaced relationship to each other, said rails respectively having
openings therein at longitudinally spaced intervals, said openings
further being aligned in a plurality of transverse rows, said
openings being of rectangular cross section and having a horizontal
width greater than the vertical depth, and a plurality of
joint-spanning load-bearing beams of rectangular cross section with
a horizontal width greater than the respective vertical depth of
each beam and extending through at least some of said rows of
rectangular openings with said rails resting slidably thereon.
2. A joint structure as claimed in claim 1, said rails having
mounted therebetween a plurality of coil springs arranged in a
plurality of longitudinally spaced, transverse rows.
3. A joint structure useful for spanning joints comprising a pair
of elongated longitudinal frames adapted to be mounted at the
respective edges of the joint, a plurality of elongated,
longitudinal rails spanning the joint in parallel, spaced
relationship to each other, said rails respectively having openings
therein at longitudinally spaced intervals, said openings further
being aligned in a plurality of transverse rows, said openings
being of rectangular cross section and having a width greater than
the depth, and a plurality of joint-spanning load-bearing beams of
rectangular cross section with a width greater than the respective
depth of each beam and extending through at least some of said rows
of rectangular openings with said rails having mounted therebetween
a plurality of coil springs arranged in a plurality of
longitudinally spaced, transverse rows, said springs balancing the
spacing between respective rails at the joint structure widens or
narrows, said spring members each having horizontal legs at
opposite ends thereof seated in leg-receiving groove means in
respective rails and diagonal end portions extending from said legs
with the tip portions of the diagonal end portions seated in
opposed groove means in respective rails.
4. A joint structure as claimed in claim 1, said longitudinal
frames having formed therein longitudinally extending cavities into
which the ends of the joint-spanning, load-bearing beams can extend
as the joint approaches its narrowest spacing.
5. A modular joint structure useful for spanning joints comprising
a pair of elongated, longitudinal frames adapted to be mounted on
respective sides of the joint, a plurality of elongated,
longitudinal rails spanning the joint in parallel relationship to
each other, plurality of joint-spanning, load-bearing beams
extending transversely across the joint and supporting the
respective rails, an elastomer tread composed of one or more tread
sections, means supporting said tread on the upper portion of each
rail with a solid elastomer strip portion of the tread above and
supported by each rail, and said solid portions being connected by
at least one shallow V-shaped wall connecting respective upper
corner portions of said solid portions of said tread.
6. A joint structure as claimed in claim 5, said tread also having
a lower, shallow V-shaped wall below and spaced from said
first-mentioned wall and defining a hollow space between said walls
and solid portions.
7. A joint structure as claimed in claim 5 wherein said tread
sections have dformable members depending from said solid portions
and interlocking in channel-forming means extending along the upper
sides of respective rails.
8. A joint structure as claimed in claim 5, said longitudinal
frames having longitudinal groove means for receiving an
interlocking member depending from the end wall of said tread
mounted on said frame, and said frame further having an elongated
lip overlying the upper corner of said tread.
9. A joint structure as claimed in claim 5, said tread comprising a
plurality of side-by-side sections extending longitudinally of the
joint and interlocking serrations formed in the contiguous,
abutting side walls of respective tread sections.
10. A modular joint structure useful for spanning joints comprising
a pair of elongated, longitudinal frames adapted to be mounted on
respective sides of the joint, a plurality of elongated,
longitudinal rails spanning the joint in parallel relationship to
each other, a plurality of joint-spanning, load-bearing beams
extending transversely across the joint and supporting the
respective rails, said frames having one or more downwardly facing,
longitudinal slots, nuts slidably positionable at any desired point
in said slot or slots, and anchor bolts having threaded ends
threaded into said nuts until the nuts and bolts bind in the slot
or slots, the shanks of said bolts projecting from the frame for
anchoring in pavement poured adjacent and beneath said frames.
11. A modular joint structure useful for spanning joints comprising
a pair of elongated, longitudinal frames adapted to be mounted on
respective sides of the joint, a plurality of elongated,
longitudinal rails spanning the joint in parallel relationship to
each other, a plurality of joint-spanning, load-bearing beams
extending transversely across the joint and supporting the rails,
said frames being composed of aligned sections, a gasket between
abutting ends of said section, said sections each having a
downwardly facing longitudinal slot portion near respective
abutting ends, a nut slidably adjustably seated in each slot
portion, a bracket mounted on the inside of each section adjacent
respective abutting ends by a bolt threaded into a respective nut
in each slot portion and bolts connecting respective pairs of
brackets of respective abutting ends for drawing said ends together
and compressing therebetween said gasket.
12. A modular joint structure as claimed in claim 11, said bolts
having threaded ends threaded into said nuts until the nuts and
bolts bind in said respective slots.
Description
INTRODUCTION
The subject invention concerns improvements in expansion joint
structures useful in the spanning of relatively wide joints in
pavement surfaces, particularly joints in pavement decks of
bridges. The latter joints have a relatively wide range of
movement, i.e., opening and closing, during expansion and
contraction of sections of a bridge deck as the environmental
temperature changes.
Expansion joints for bridges heretofore have involved heavy
assemblies or subassemblies brought to the bridge site and mounted
in the bridge joints by cranes or the like. One well known type of
bridge expansion joint comprises a pair of heavy duty plates
fixedly attached to opposite sides of the joint. The plates have
projecting, interfitting fingers which span the joint and can move
relative to each other if the joint opens or closes. Joints of this
type cannot be effectively sealed against leakage of water from
rain or melted ice or snow. The latter two in particular carry with
them corrosive salts which, over a period of time, damage the
superstructure of the bridge, its piers, and/or abutments.
Bridge designers and engineers have been giving more attention in
recent years to use of bridge joints which are sealed against
leakage of water and/or solids through the joint onto the
underlying structure of the bridge. A relatively recent design for
a sealed bridge joint embodies longitudinal, spaced rails resting
on joint-spanning beams. Laterally compressible elastomer seals are
compressed between the rails slightly below the upper surface
thereof. The upper surfaces of the rails lie substantially in the
plane of the bridge deck. The tires of automobiles crossing the
joint run across these upper surfaces of the rails while the
elastomer seals are recessed enough to avoid contact with the
automobile tires.
These known expansion joints are manufactured and preassembled at
an off-site facility, compressed to a width allowing them to be
inserted in the joint, hauled to the bridge site and laid in the
joint with heavy duty cranes. Once installed, they are difficult to
repair. Repair or replacement of a component usually involves
closing the entire bridge or several lanes thereof to traffic in
order that heavy duty equipment may be brought to the joint site to
raise the expansion joint, repair it, and replace it back in the
joint.
THE INVENTION HEREIN
This invention provides improvements in expansion joints having
ranges of movement which are lesser than those attainable in the
modular bridge joint of the aforesaid copending application, the
latter having load-bearing beams which are segmentally
interconnected to allow the beams to lengthen or shorten the
movement of the joint. The improvements of the subject invention
reside in modular expansion joints having a shallower overall depth
attained through, inter alia, the use of load-bearing beams of
solid material, e.g., aluminum or steel, laid in the joint in a
manner where the width exceeds the depth of the respective beams.
Further improvements of the invention reside in the configuration
of the seal and tread which spans and covers the entire joint,
particularly in the provision of upper and lower V-shaped walls
with a hollow space therebetween in the sections of the tread
extending between respective longitudinal rails. Other improvements
reside in the manner of mounting the outermost rails in the
longitudinal frames on opposite sides of the joints.
The metal components of the joint include longitudinal frames
mounted in stepped edges of a concrete pavement deck, such as the
concrete pavement deck of a bridge, or in other concrete structures
such as pavement sections adjoining or contiguous to bridges. The
longitudinal rails extend longitudinally of the joint in
substantially equally spaced relationship. These rails may be made
in short sections and spliced together in end-to-end relationship
in the manner shown in the aforesaid application.
The frames, rails and load-bearing beams preferably are fabricated
as aluminum alloy extrusions. Each extrusion is relatively light in
weight so that the joint can be assembled manually at the joint
site without using heavy duty equipment. The rails are of
relatively short lengths, e.g., 12 feet. This feature allows the
joint to be constructed or repaired on a one lane at a time basis,
while keeping other lanes open to traffic flow during maintenance.
The frame sections provided at each side of the joint also
preferably are made in short sections and may have a gasket between
abutting ends to seal the abutting ends against seepage of water at
these points.
The joints of the invention are constructed in standard unit
lengths and will span joints of medium width, e.g., joints having a
maximum opening of 8-12 inches. The coil springs between the rails
maintain substantially equal spacing therebetween regardless of
joint width. The ends of the coil springs respectively are composed
of horizontal legs which seat in a groove provided in the lower
portion of the I-beamlike rails and a diagonal leg, the tip of
which seats in an opposite groove of said rails.
The load-bearing beams or bars extend through aligned openings
provided in the respective rails and span the entire joint between
respective outer rails. The longitudinal frames at each side of the
joint are provided with a recess segment into which the ends of the
load-bearing beams or bars can project when the joint closes and
the ends of the load-bearing beams or bars begin to extend into the
longitudinal frame members of the joint.
The frames at the edges of the joint are extrusions which may be
placed at the time of the initial deck paving. Secure mounting of
the frames in the deck pavement is accomplished by anchor bolts
embedded in the concrete and tied to reinforcing steel in the deck
pavement.
The elastomer seal and tread provides a continuous seal from curb
to curb without joints subject to leakage. The seal has
longitudinal beads which snap into channels on the upper edges of
the rails thus making the seal easy to install or replace. The seal
covers all of the metal structure of the joint and is the only part
which could be damaged by snowplows. The interlocking of the seal
with the rails assures positive sealing in that the seal must move
as the joint components move during thermal expansion or
contraction of the joint.
THE DRAWINGS
A preferred embodiment of the invention is illustrated in the
drawings, wherein:
FIG. 1 is a vertical section of an expansion joint with the
concrete segments of the joint shown in fragment;
FIG. 2 is a section view taken on section plane 2--2 of FIG. 1
without the elastomer tread;
FIG. 3 is a fragmentary, bottom plan view of abutting sections of
an end frame member of the joint; and
FIG. 4 is a fragmentary detail in side elevation of the bracket and
bolt connection for the abutting sections.
Referring to the drawings, the modular expansion joint 10 spans a
space 14 between adjacent sections 11 and 12 of a concrete bridge
deck. The sections 11 and 12 each have a step 13 on which the
longitudinal end frames 14 and 15 are seated and held in place by
conventional J-bolts or other type of anchor bolts 16 or like
holding devices. The anchor bolts have treaded shanks which tread
into nuts 17 seated in longitudinal slots 18 and 19 which extend
the length of the frame sections 14 and 15. The nuts 17 are placed
in the slots 18 at any desired longitudinal spacing. The J-bolts
may then be treaded into the nuts until the bolt and nut bind in
the respective slots 18 and 19. This mounting of the nuts in the
slots has proven very advantageous in installation or mounting of
the frame sections on the bridge structure. The nuts may be
positioned anywhere in the slots and thus can be located on the job
site to allow the anchor blots to interfit with or avoid
interfering contact with other components of the bridge deck or its
understructure.
The longitudinal end frames preferably are aluminum extrusions
having an upper, rearwardly projecting lip 20 forming an undercut
21 beneath which concrete can flow. The frames 14 and 15 preferably
also have a small forward lip 22 adapted to overlie the respective
ends of the elastomer tread 23. The lip 22 helps provide a seal
against intrusion of sand and other incompressibles between the
seal and the frame and also aids in holding the respective ends of
the elastomer tread in position in the respective end frames 14 and
15.
The lower portion of the end frames 14 and 15 includes a rearwardly
directed wall 24 joined to the bottom wall 25 by a connecting wall
26 which flares in an upward direction to accommodate the
longitudinal slot 18. A chamber 27 is provided between the upper
and lower walls 24 and 25, which chambers will receive and
accommodate the ends of the load-bearing beams or bars 28 when the
joint 10 closes to its minimum or near minimum width.
The lower wall 25 of the end frame includes an enlarged segment to
accommodate the longitudinal slot 19 and further form a seat 30 for
the lower wall 31 of the respective end rails 32, which are mounted
on the respective end frames.
The intermediary rails 33 are of the same cross section as the
outermost rails 32. Their lower walls 39 with upturned ends 34
provide longitudinal rigidity for the rails and forming grooves 48,
later described. Their upper ends have wall segments 35 like the
bottom wall 39 and further include U-channels 36 with inwardly
directed lips 37 for receiving deformable, dovetailed tongues
38.
The elastomer tread 23 may be made in sections which fit
side-by-side across the width of the joint. Each section includes
an end wall 40 having a sawtoothed or serrated upper side edge 41.
The latter interlock and form a seal against intrusion of water
between abutting faces of the tread sections. The contacting faces
of the end walls 40 are positively sealed against water leakage
therebetween by tight-fit and compression of the portions of
tongues 38 which seat between the neck formed by the opposed,
inwardly directed lips 37. The side-by-side, lower portions of the
abutting edges together form as a composite dovetailed tongues
38a.
The remainder of the elastomer tread may include one or more solid
elastomer segments 42 between the end walls 40, each solid segment
being located above a U-channel 36 with a dovetailed tongue 38
depending therefrom. The intermediary portions of the tread
sections between the respective rails are composed of a shallow,
V-shaped upper wall 43 and a shallow, V-shaped lower wall 44 with a
hollow space 45 therebetween. As the joint closes and the elastomer
tread is pushed inwardly from its respective ends, the shallow,
V-shaped walls 43 and 44 assume a deeper, V-configuration. Only the
upper wall 43 is essential to make the seal waterproof. However,
the lower wall 44 gives symmetric stability to the tread sections
and serves as a second sealing surface, should the upper wall 43
become punctured or torn.
Adjacent one side of each load-bearing beam or bar 28 there is
provided a coil spring 46 between each rail. The respective rails
have opposed upper and lower grooves 47 and 48 on each side
thereof. The lower groove 48 on each rail receives a horizontal leg
49 at each end of the coil spring while the upper groove 47
receives the end 50 of a diagonal leg 51 extending from one end of
the respective legs 49. These diagonal legs provide a useful
function in holding the coil springs 46 in place under vibrations
imparted to the joint by traffic passing thereover. Springs without
such diagonal legs and mounted only by the horizontal legs 49 have
been found, on occasion, to work loose as a result of the
vibrations imparted on the joint by traffic moving thereover.
The outer rails 31 and 32 are held in position on the longitudinal
end frame members 14 and 15 by a T-bar 52, the cross leg of which
is seated in opposed grooves 53 and 54 of the frame. The other leg
55 is connected by bolt 56 to a T-bar 57 having edge portions
seated in the opposed grooves 58 and 59 of the outermost rails. One
or both of the parallel legs of the T-bars may have a slot allowing
for adjustable positioning of the respective bars in the end frames
and the outermost rails.
The load-bearing beams or bars 28 have attached at opposite ends
thereof by bolts 60 or other suitable means, a plate 61 whose
length is greater than the width of the load-bearing beams or bars
28. The respective plates 62 serve as stops to prevent either end
of the beams or bars 28 from passing through the outermost rails 31
and 32.
The half tongues 38b of the elastomer tread are seated in end
frames by providing an inverted L-leg 62 spaced from and directed
toward the wall portion 63 of the end frames. The horizontal lip of
the half tongues 38b lies beneath the horizontal leg of the
inverted L-leg 62 continually along the longitudinal dimension of
the joint. The vertical leg of the half tongues 38b are compressed
between the end of the L-leg and the opposing face of wall portion
63 to make a constant, water-tight seal. This interlocking, coupled
with the lips 22 overlying the upper side of the outer edge of the
tread section, hold the tread section firmly in place in the
respective end frames. Further, the upper portion of the wall 63
may be provided with serrations 64 to match and receive the
serrated side portion 41 of the outermost wall of the seal section
forming the tread. This further aids in preventing seepage of
moisture and incompressibles between the contacting faces of the
side walls 40 of the outermost seal and the face of the wall 63 of
the frame.
Preferably the rectangular opening 65 in the intermediary rails 33
and outermost rails 32 are lined with a wear-resistant bushing 66,
e.g., a gasket-like lining of Adiprene.
In preferred forms of the invention, the rails 33 and 32 and the
end frames 14 and 15 are aluminum extrusions approximately 12 feet
in length, which length corresponds to one lane of a dual line or
multilane highway or bridge. The abutting ends of the rails 32 and
33 are spliced together by elongated plates of the type shown in
our application aforesaid, which splicing plates are seated in the
opposed grooves 47 and 48 on each side of the respective rails at
the point or points of splicing. By using lengths corresponding
substantially to lane widths of the highways or bridges, it is
possible to repair or inspect or conduct periodic maintenance of
the joint by closing off only one late at any given time in the
performance of the aforesaid functions.
The invention thus provides a modular joint structure utilizing a
pair of elongated, longitudinal frames mounted firmly in concrete
or other paving material on steps at the respective edges of the
joint. A plurality of elongated, longitudinal rails span the joint
in parallel, spaced relationship to each other. These rails
respectively have rectangular openings therein disposed at
longitudinal intervals along the rails. The openings are aligned in
a plurality of transverse rows through which joint-spanning,
load-bearing beams of rectangular cross section extend through at
least some, and usually all, of the rows of rectangular openings.
The respective rails, excepting the two outermost rails, rest
individually and independently slidable on the rectangular
load-bearing beams.
To maintain substantially equal spacing between the respective
rails, the modular joint structure utilizes a plurality of coil
springs mounted between respective rails and preferably in an
arrangement providing a plurality of longitudinally spaced,
transverse rows close to but spaced from one side of the
load-bearing beam.
The modular joint is sealed over its entire width and length by
providing an upper, elastomer tread having solid elastomer segments
above and supported on the upper portions of the respective rails,
preferably by deformable beads or tongues interlocked in
channel-forming members on the upper surface of the rails. The
intermediary portions of the treads between the rails preferably
comprise upper and lower, vertically spaced, shallow V-shaped walls
with a hollow space therebetween. As the joint closes, these upper
and lower walls deform into a deeper V-configuration.
The tread preferably is composed of a series of side-by-side
elastomer segments made from low crystallization neoprene
formulations. The abutting edges of the treads with the sides of
the longitudinal end frames and with another side of an adjacent
tread segment for a water-tight seal. In the illustrated
embodiment, the tread sections comprise three side-by-side sections
67, 68 and 69 of identical cross section and a section 70 which is
one-half the width of the tread sections 67-69. If desired, the
tread sections may comprise three or more integrally formed
sections, each of which corresponds in cross section to section 70
in the same manner as sections 67-69 comprise the equivalent of two
sections 70. By such dimensions and geometry of the tread sections,
they can be used to span joints of varying width dimension through
appropriate selection of the tread section widths needed to span
the particular joint between the longitudinal end frames 14 and
15.
The sections of the longitudinal end frames 14 and 15 preferably
are also sealed at their junctures by an elastomer gasket.
Referring to FIGS. 3 and 4, the end portions of the longitudinal
slots or grooves 19 of abutting frame sections 14a and 14b have
placed therein a nut 71. An L-bracket 72 is fixedly attached to the
underside of the bottom wall 25 of each frame section, the
horizontal leg 73 of which is held by a bolt 74. The shank of the
bolt projects through a hole or slot (not shown) in the leg 73 and
is threaded into the nut 71 to hold L-bracket 72 fixedly on the
bottom wall.
The vertical leg 75 of each L-bracket has a bolt-receiving hole
through which the shank 76 of bolt 77 extends. An elastomer gasket
78 conforming to the cross section of the frame 14 is placed
between the frame sections 14a and 14b and is compressed
therebetween by drawing up tightly the bolt 77 and its nut 79.
Similar bracket and bolt means may be mounted in the longitudinal
slots or grooves 18 to draw the abutting frame sections together
and give a more uniform compression of the gasket 78.
It is through that the invention and its numerous attendant
advantages will be fully understood from the foregoing description,
and it is obvious that numerous changes may be made in the form,
construction and arrangement of the several parts without departing
from the spirit or scope of the invention, or sacrificing any of
its attendant advantages, the form herein disclosed being a
preferred embodiment for the purpose of illustrating the
invention.
* * * * *