U.S. patent application number 10/989301 was filed with the patent office on 2006-05-18 for retaining wall construction element.
This patent application is currently assigned to THE NEEL COMPANY. Invention is credited to John M. Carey, Thomas C. Neel.
Application Number | 20060104725 10/989301 |
Document ID | / |
Family ID | 36386469 |
Filed Date | 2006-05-18 |
United States Patent
Application |
20060104725 |
Kind Code |
A1 |
Carey; John M. ; et
al. |
May 18, 2006 |
Retaining wall construction element
Abstract
A precast concrete retaining wall construction element for
retaining a soil mass in a railway installation or the like
includes an upstanding solid face panel having the shape of a
hexahedron where a rectangular front wall and an integral stem. The
front wall defines an area of between about 18.75 and 75 square
feet and wherein the ratio of the width of the face panel to its
height is between about 0.75 to about 3.0. A reinforced element
including an upward extension, an improved shear key and stacked
arrangement are also disclosed.
Inventors: |
Carey; John M.; (Ashburn,
VA) ; Neel; Thomas C.; (Springfield, VA) |
Correspondence
Address: |
DENNISON, SCHULTZ, DOUGHERTY & MACDONALD
1727 KING STREET
SUITE 105
ALEXANDRIA
VA
22314
US
|
Assignee: |
THE NEEL COMPANY
|
Family ID: |
36386469 |
Appl. No.: |
10/989301 |
Filed: |
November 17, 2004 |
Current U.S.
Class: |
405/286 ;
405/262; 405/284 |
Current CPC
Class: |
E02D 29/0266
20130101 |
Class at
Publication: |
405/286 ;
405/284; 405/262 |
International
Class: |
E02D 17/00 20060101
E02D017/00; E02D 5/00 20060101 E02D005/00 |
Claims
1. A precast concrete retaining wall construction element for
retaining a soil mass in a railroad application, said element
comprising: an upstanding solid face panel having the shape of a
hexahedron with front and rear walls, a top wall, two side walls
and a bottom wall and wherein the area of said front panel is about
371/2 square feet with a width of about 71/2 feet, a height of
about 5 feet and a thickness of about 8 inches; an integral stem
extending rearwardly from said rear wall of said face panel in a
generally T-shaped arrangement for embedment in a soil mass; said
integral stem having an upper wall, a bottom wall, two side walls,
a rear wall and said upper and bottom wall each defining a notch
therein and each of said side walls including a pan insert therein
and in which said integral stem has a width of about 7 inches; a
shear key constructed and dimensioned to fit within one of said
notches in one of said upper and bottom walls of said stem and
adapted to fit within a corresponding notch in an abutting stem of
a second element placed on top of or below said retaining wall
construction element; and wherein a plurality of stacked elements
embedded in a soil mass will withstand a lateral earth pressure
from two rairroad tracks adjacent to a retaining wall construction
of 1,882 pounds per square foot of track.
2. (canceled)
3. A precast concrete retaining wall construction element according
to claim 1 in which said face panel and said integral stem have
equal heights.
4. A precast concrete retaining wall construction element according
to claim 1 in which the face of each of said pan inserts defines an
area of between about 0.56 square feet and 1.56 square feet.
5. A precast concrete retaining wall construction element according
to claim 1 in which a face of each of said pan inserts defines an
area of about one square foot.
6. (canceled)
7. A precast concrete retaining wall construction element according
to claim 1 in which each of said notches has a width of about one
foot and a depth of about 0.5 feet.
8. A precast concrete retaining wall construction element according
to claim 1 in which each of said shear keys extend outwardly from
said integral stem on each side thereof by distance of about
one-half inch.
9. A precast concrete retaining wall construction element according
to claim 4 in which said integral stem includes a plurality of rows
of vertically aligned pan inserts to thereby provide solid concrete
columns between said columns.
10. A precast concrete retaining wall construction element
according to claim 1 which includes a trapezoidal support member
between said face panel and said integral stem.
11. A precast concrete retaining wall construction element
according to claim 1 in which said face panel includes an upper
extension above the height of said integral stem and in which said
upper extension has a height of 21/2 feet, 33/4 feet or 5 feet.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a precast concrete retaining wall
construction element and more particularly to a precast concrete
retaining wall construction element for retaining a soil mass.
BACKGROUND FOR THE INVENTION
[0002] Precast concrete retaining wall construction elements are
known. For example, a U.S. Patent of O'Neill, U.S. Pat. No.
4,684,294, discloses a retaining wall construction element having a
forwardly disposed rectangular face panel and an integral embedment
beam which extends into and is anchored by the soil mass. The
embedment beam includes upper and lower walls, side walls and a
sloping rear wall. In addition, the embedment beam includes notches
for engagement which transverse support beams which form a soil
interruption system to reduce internal pressure and which serve to
lock the embedment beams together. The embedment beams further
include pan inserts and a V-shaped groove disposed in the sloping
rear wall to increase the frictional engagement between the
embedment beam and the soil mass. The construction elements in
accordance with the O'Neill patent have been widely used for many
applications.
[0003] However, it is presently believed that there is a large
commercial market for an improved precast concrete retaining wall
construction element in accordance with the present invention.
There should be a large commercial market for such elements because
they are particularly applicable for railroad embankments and other
large installations that may be repeatedly subjected to significant
forces and/or vibrations.
[0004] The improved precast concrete retaining wall construction
elements in accordance with the present invention fully meet the
American Railway Engineering and Maintenance Association (AREMA)
requirements for railroad installations. Further, such elements are
economical to manufacture, ship and to install in a safe manner
which reduces the risk for employees working on such installations.
Further, the precast concrete retaining wall construction element
in accordance with the present invention, are sized for efficient
shipment by truck and have a pleasing appearance.
BRIEF SUMMARY OF THE INVENTION
[0005] In essence, the present invention contemplates a precast
concrete retaining wall construction element for retaining a soil
mass. The element includes an upstanding solid face panel having
the shape of a hexahedron with front and rear walls, a top wall,
two side walls and a bottom wall. An important feature of the
present invention resides in the area of the front wall which is
between about 18.75 and about 75 square feet and wherein the ratio
of the width of the face panel to the height of the face panel is
between about 0.75 to about 3.0.
[0006] In a preferred embodiment of the invention, a "standard
unit" includes a front wall having an area of between about 30
square feet and about 40 square feet, preferably about 371/2 square
feet and wherein the ratio of the width of the face panel to the
height of the face panel is between about 0.75 to about 3.0, and
preferably between about 1.2 to about 1.6.
[0007] The element also includes an integral stem or embedment
member extending rearwardly from the rear wall of the face panel in
a generally T-shaped construction. The integral stem has an upper
wall, a bottom wall, two side walls, a rear wall and with one or
more notches defined in the upper and bottom wall. Further, each of
the side walls of the integral stem includes one or more pan
inserts therein. A shear key is constructed and dimensioned to fit
within one of the notches in one of the upper and bottom walls of
the stem and is adapted to fit within a corresponding notch in an
abutting stem of a second element which is placed on top of or
below the retaining wall construction element.
[0008] In a second embodiment of the invention, the precast
concrete retaining wall construction element wherein each of the
elements set forth in the previous paragraph includes steel
reinforcing rods extending through and encased by the integral stem
and the face panel with one of the reinforcing bars extending
outwardly in a first direction of the face panel and the other of
the reinforcing bars extending outwardly in an opposite direction
into the face panel.
[0009] In a third embodiment of the invention, the precast
retaining wall construction element for retaining a soil mass
includes the elements of the first embodiment of the invention and
also includes one or more shear keys which fit within one of the
notches in one of the upper or bottom walls and is adapted to fit
within a corresponding notch in an abutting stem of a second
element placed on top of or below the retaining wall construction
element. In this embodiment of the invention, the shear key
includes a face having a cross sectional area of about one square
foot.
[0010] A fourth embodiment of the invention includes all of the
elements of the first embodiment. However, in this embodiment the
face panel includes an extension extending upwardly above the
integral stem by distance of up to about 5 feet. A 5 foot extension
on top of a 5 foot height of a standard unit gives a total height
of 10 feet which is the limit due to shipping and results in a face
panel having a cross sectional area of about 75 square feet. In
this example, the area of the upper extension and the portion of
the front wall below the extensions are each about 371/2 square
feet.
[0011] A fifth embodiment of the invention contemplates a plurality
of stacked elements wherein a first element as defined in the first
embodiment of the invention is stacked on top of an element in an
aligned and abutting relationship. In this embodiment of the
invention, a retaining wall construction element in accordance with
the fourth embodiment of the invention may be used as an upper or
top element in the stacked array of such elements. Further, the
shear key is constructed and dimensioned to fit within one of the
notches in an upper wall of one stem and within a corresponding
notch in a bottom wall of the stem of the second element.
[0012] The invention will now be described in connection with the
accompanying drawings wherein like reference numerals have been
used to designate like parts.
DESCRIPTION OF THE FIGURES
[0013] FIG. 1 is a perspective view of a retaining wall
construction element in accordance with a first embodiment of the
invention;
[0014] FIG. 2 is a side elevational view of the retaining wall
construction element shown in FIG. 1;
[0015] FIG. 2A is a sectional view of the element shown in FIG. 2
and taken along the line A-A in FIG. 2;
[0016] FIG. 2B is a sectional view of the element shown in FIG. 2
and taken along the line B-B in FIG. 2;
[0017] FIG. 3 is a top view of the element shown in FIG. 2;
[0018] FIG. 4 is a front view of a retaining wall construction
element in accordance with a second embodiment of the
invention;
[0019] FIG. 5 is a side elevational view of the elements shown in
FIG. 4;
[0020] FIG. 5A is a cross-sectional view taken along the line A-A
in FIG. 5;
[0021] FIG. 5B is a cross-sectional view taken along the line B-B
in FIG. 5;
[0022] FIG. 6 is a top view of the element shown in FIGS. 4 and
5;
[0023] FIG. 7 is a side view of a stem portion of an element in
accordance with the present invention and including two pair of
corresponding notches and a shear key in one pair of corresponding
notches;
[0024] FIG. 8 is a side view of a shear-key in accordance with one
embodiment of the invention;
[0025] FIG. 9 is a front view of the shear key shown in FIG. 8;
[0026] FIG. 10 is a plan view of the shear key shown in FIGS. 8 and
9;
[0027] FIG. 11 is a side view in accordance with another embodiment
of the invention;
[0028] FIG. 12 is a side view of a retaining wall construction
element in accordance with another embodiment of the invention;
[0029] FIG. 13 is a top view of the elements shown in FIG. 12;
[0030] FIG. 13A is a sectional side view illustrating the steel bar
reinforcement as used in one embodiment of the invention;
[0031] FIG. 13B is a sectional front view illustrating the steel
bar reinforcement as used in the embodiment of the invention shown
in FIG. 13A;
[0032] FIG. 14 is a side view of a retaining wall construction in
accordance with another embodiment of the invention;
[0033] FIG. 14A is a side sectional view which illustrates the
steel reinforcing rods in another embodiment of the invention;
[0034] FIG. 14B is a front sectional view which illustrates the
steel reinforcing rods in a face panel in accordance with the
embodiment of the invention shown in FIG. 14A;
[0035] FIG. 15 is a side view of a retaining wall construction
element according to a further embodiment of the invention which
shows the steel reinforcing elements;
[0036] FIG. 16 is a front view of the elements shown in FIG. 15 and
which shows the steel reinforcing rods disposed therein;
[0037] FIG. 17A is a side view of a shear key which includes a pair
of U-shaped reinforcing bars;
[0038] FIG. 17B is a schematic illustration of the front view of a
pair of U-shaped reinforcing rods as used in the embodiment of the
invention shown in FIG. 15;
[0039] FIG. 18 is a load diagram which illustrates typical lateral
earth pressures from two railroad tracks adjacent to a retaining
wall construction in accordance with the present invention;
[0040] FIG. 19 is a side view of a typical rail facility
application; and
[0041] FIG. 20 is a perspective view of one embodiment of the
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
[0042] FIGS. 1, 2, 2A, 2B and 3 show a precast concrete retaining
wall construction element 2 in accordance with a first embodiment
of the invention. As shown, the element 2 includes a face panel 12
having a height of about 5 feet and a width of about 71/2 feet. In
a preferred embodiment of the invention, the face panel defines a
front face having an area of between about 30 and 40 square feet
and preferably about 371/2 square feet. The dimensions are based on
various considerations including the requirements of the American
Railway Engineering and Maintenance Association (AREMA). For
example, the lateral pressure required for various installations
must be met. In the present case i.e., one that is used for rail
facility applications such as grade separation structures, bridge
approaches and abutments, slope stabilization etc. each
installation must comply with the AREMA requirements and at the
same time optimize the value of the installation. For example,
dimensions are also based on various considerations including the
safety of workers, transportation and manufacturing costs, raw
material costs, appearance and loading.
[0043] As illustrated, the element 2 includes an integral stem 14
or embedment beam member which is formed in a generally T-shaped
arrangement. The face panel 12 and integral stem 14 which are
integrally cast from concrete at a manufacturing site. The face
panel 12 also includes a forward wall 16, a rear wall 18, side
walls 20, a top wall 21 and a bottom wall 22. An integral cast
concrete trapezoidal support member 23 extends rearwardly from the
rear wall 18 with its base or widest portion adjacent to the rear
wall and its top portion extending into the integral stem 14. As
illustrated, the top wall 21 defines a flat surface. Also in this
embodiment of the invention, the face panel 12 includes an upper
extension above the stem 14 which retains additional fill on the
top of an installation.
[0044] For railroad applications, a number of considerations call
for an upward extension of the face panel as for example, as
required to allow an overburden of 2 to 3 feet of soil to provide
an obstacle free layer of soil below the tracks and above the
integral stems. This 1 to 3 feet layer also accommodates for a 1 to
2 percent grade and for electrical cable for signals.
[0045] As shown in the figures, the integral stem 14 is joined to
the rear wall 18 of the face panel 12 by means of the trapezoidal
support member 23 which reduces stress at the juncture. The
integral stem 14 includes an upper wall 25, a bottom wall 26 and
side walls 27 and 28. The upper wall 25 and lower wall 26 each
define one or more notches 30 and 32 for engagement with a shear
key (not shown in FIGS. 1 and 2). The side walls 27 and 28 each
include a series of pan inserts 33 or indentations which become
filled with compacted soil to help hold the element 2 in place
within a soil mass.
[0046] FIGS. 2, 2A, 2B and 3 illustrate a preferred embodiment of
the invention wherein a plurality of steel reinforcing bars, rods
or rebars are used to reinforce the front panel 12 and integral
stem 14. As illustrated, the integral stem 14 includes a plurality
of pan inserts 33 which are disposed in a plurality of parallel
rows and columns. As illustrated, a plurality of completely encased
reinforcing sets of rebars 35 extend parallel along the integral
stem 14 in an upper and lower portion thereof and in between the
horizontal rows of pan inserts 33. The rebars 35 also extend into
the front face panel 12. As illustrated, each of the rebar sets
include two rebars with one of the rebars extending into the face
panel 12 in a first direction and a second of the rebars extending
in an opposite direction within the front panel 12. The front panel
12 also includes a plurality of vertically and horizontally
disposed rods 36 and 37 respectively. As shown, the rebars 36 and
37 also extend into an upper extension 40 of the face panel 12. A
plurality of vertically disposed rebar pairs 38 are disposed in the
integral stem 14 with one pair disposed between each column of pan
inserts 33 with one of said pair disposed on one side of the rebar
35 and a second of the pairs on an opposite side as shown in FIG.
2A. The arrangement of the horizontal rebars 35 is shown more
clearly in FIG. 2B wherein six rebars are shown two in each set of
three in the horizontally disposed reinforcing rods.
[0047] A further embodiment of the invention is illustrated in
FIGS. 4, 5, 5A, 5B and 6. As shown therein the element 2 includes a
face panel 12 having a forward wall 16, a rear wall 18, side walls
20, a top wall 21 and a bottom wall 22. The element 2 also includes
an integral stem 14 which extends rearwardly from the rear wall 18
to define a T-shaped construction. As illustrated, the stem 14 has
the same height as the front panel 12 i.e., about 5 feet and as
shown as a length of 12 feet which maybe reduced in successive
layers from the bottom of a stacked array to the top thereof. Such
lengths can go to 30 feet.
[0048] As illustrated in FIGS. 5, 5A, 5B and 6, the integral stem
14 includes a plurality of pan inserts 33 arranged in two parallel
rows and five parallel columns. In a preferred embodiment of the
invention, the pan inserts 33 have a height of about 1 foot, 5
inches and a width of about 1 foot but may vary from about 1 foot
to 1.5 feet in height and from about 0.5 feet to 1.0 feet in width.
In addition, there are corresponding and aligned pan inserts 33 on
each side of the integral stem 14 each of which constitutes a
recess of about two inches. In this embodiment of the invention,
the integral stem has a height of about 5 feet which is equal to
the height of the face panel 12 and a width of about 7 inches which
is slightly less than a thickness of about 8 inches for the face
panel.
[0049] A further embodiment of the present invention relates to a
shear key as illustrated in FIGS. 7-11, 17A and 17B. As
illustrated, a shear key 37 is constructed and dimensioned to fit
within the notches 30 or 32 and adapted to fit within a
corresponding notch in an abutting stem 14 when placed on top of or
below another retaining wall element. As illustrated, the shear key
37 is in the form of a polyhedron having eight sides with two
opposite sides (a cross section) defining a hexagon. The key 37 is
preferably about eight inches between opposite sides i.e., slightly
larger than the seven inch width of the integral stem 14 so that it
extends outwardly by about 1/2 inch on each side of the integral
stem to facilitate handling of the shear key 37. FIGS. 8, 9 and 10
illustrate a shear key 37 which has a height of about 71/2 inches
and a width of about 11 inches from opposite sides of the hexagonal
face and about 9 inches along the top and bottom thereof.
[0050] In a further embodiment of the invention, a shear key 38
includes a circular passage way 39 extending through the key from
one hexagonal face side to the other to lighten the key and further
facilitate handling.
[0051] In another embodiment of the invention (see for example,
FIGS. 17A and 17B) the shear key 37 includes fully encased steel
reinforcing rods 40 and 41. In this embodiment each of the
reinforcing rods 40 and 41 are U-shaped with two legs and a
connecting member. In this embodiment, the shear key includes a
first portion adjacent to one of the hexagonal sides and a second
portion adjacent to an opposite hexagonal side. A connecting member
of a first U-shaped reinforcing rod 40 is disposed in and fully
encased by the first portion of the shear key 37 with its leg
portions extending into the shear key. Further, the connecting
member of the second U-shaped reinforcing rod 41 is disposed in and
fully encased by the second portion of the shear key 37 with its
legs extending inwardly into the key 37. As illustrated, the
connecting members of the reinforcing rods 40 and 41 are disposed
in a crossed-relationship as illustrated in FIG. 17B.
[0052] A still further embodiment of the invention is shown in
FIGS. 12A, 12B and 13 and is generally similar to the elements
shown in FIGS. 1-3. For example, the precast concrete retaining
wall construction element in accordance with this embodiment of the
invention includes a face panel 12 having a width of 71/2 feet and
a height of about 5 to 10 feet. The additional height i.e., above 5
feet, is used in an uppermost element to resist movement of a top
layer of soil in a railroad installation. The element also includes
an integral stem 14, pan inserts 33 and notches 30 but does not
include notches 32 in an upper wall 25 of the integral stem 14. A
key feature in this embodiment of the invention resides in one or
two integral reinforcing elements 45. This integral reinforcing
element may take the form of a single wall or pair of walls as
shown in FIG. 12B and extends above the integral stem by about
2/3's of the distance to the top of the front wall 12. The
reinforcing elements 45 may take the form of a pair of support
walls 45 as shown in FIG. 13.
[0053] Another embodiment of the invention is illustrated in FIGS.
14, 14A and 14B. As shown in FIG. 14, a precast concrete retaining
wall construction element is generally similar to the element shown
in FIGS. 12A, 12B and 13 and includes a face panel 12, an integral
stem 14 and a pair of integral reinforcing elements 45. However, as
shown in FIGS. 14, the element 2 also includes one or two
buttresses 47 between the integral stem 14 and integral reinforcing
element 45 to provide further support for an extending front panel
12. The buttresses 47 and support members are used to provide
further support for a front panel that extends upwardly from the
upper wall of the integral stem 14 by between about 3 to 5 feet so
that the front panel may have a height of between 8 to 10 feet.
[0054] In the aforementioned embodiment, as shown in FIG. 14, it
may also be desirable to provide further reinforcement with rebars
or other steel reinforcing rods as shown in FIGS. 14A and 14B. As
shown in FIG. 14A, a pair of rebars pass through and are encased by
the panel 12, reinforcing elements 45 and buttresses 47 and extend
down into the integral stem 14. In addition, the integral stem 14
includes a plurality of U-shaped reinforcing rods between columns
of pan inserts as well as a plurality of rebars above, between and
below the rows of pan inserts.
[0055] FIGS. 15 and 16 illustrate a modification of the embodiment
shown in FIGS. 14, 14A and 14B. In FIGS. 15 and 16, the face panel
12 has a height of between about 5 feet, 6 inches to about 7 feet,
6 inches and integral stem 14 of about 2 feet, 6 inch height. The
integral stem 14 includes a single row of pan inserts 33 with a
pair of rebars above the pan inserts and a pair of rebars below the
inserts. Reinforcing rods extend from an upper portion of the face
panel through the buttresses and into the integral stem 14. The
configuration of reinforcing rods of the face panel is shown in
FIG. 16.
[0056] FIG. 18 is a load diagram that shows typical lateral earth
pressures from two railroad tracks adjacent to a retaining wall
construction in accordance with the present invention. The standard
heavy rail (Cooper E-80) load applied for the present invention is
1,882 pounds per square foot of track and is based on AREMA,
Section 2.2.3C. The retaining wall construction is designed for the
sum of the lateral earth pressure plus the surcharge loads from the
adjacent tracks. The lateral earth pressure from the train
surcharge was calculated as a strip load based on a Boussinesq
distribution as provided in AREMA, Section 20.3.2.2. Other
consideration in developing precast concrete retaining wall
construction elements in accordance with the present invention
include manufacturing and raw material costs, shipping costs,
safety of the workers, labor costs, etc.
[0057] A typical railroad application is illustrated in FIG. 19.
Such applications may be applicable for grade separation
structures, bridge approaches and abutments, track widening, slope
stabilization, railroad yard improvements, platforms, service and
access roads, loading and unloading facilities and wing walls.
[0058] FIG. 20 illustrates one form of the invention, which is
particularly applicable for railroad installation. As shown, a
precast concrete retaining wall construction element 2' includes a
face wall 16' having an upper extension 20', a support member or
haunch 23' and a buttress 47' which connects the upper extension
20' and integral stem 14'.
[0059] It should also be recognized that at times the upper
extension may be added to any of the standard units which presently
include half units having a face panel with a height of 21/2 feet
and width of 71/2 feet, a 3/4 unit wherein the face panel is 3.75
feet by 71/2 feet and a full unit which is 5 feet by 71/2 feet and
wherein the maximum height of a unit is 10 feet.
[0060] While the invention has been described in connection with
its preferred embodiments, changes and modifications may be made
therein without departing from the scope of the appended
claims.
* * * * *