U.S. patent application number 12/420592 was filed with the patent office on 2010-10-14 for subsurface drainage system and drain structure therefor.
This patent application is currently assigned to Airfield Systems, L.L.C.. Invention is credited to Charles R. Blackwood.
Application Number | 20100260546 12/420592 |
Document ID | / |
Family ID | 42934509 |
Filed Date | 2010-10-14 |
United States Patent
Application |
20100260546 |
Kind Code |
A1 |
Blackwood; Charles R. |
October 14, 2010 |
SUBSURFACE DRAINAGE SYSTEM AND DRAIN STRUCTURE THEREFOR
Abstract
A subsurface drainage assembly for directing fluid drainage from
a surface is disclosed. The subsurface drainage assembly includes a
plurality of drain structure panels that include a plurality of
spaced apart tubular support members arranged to define a unit
having a plurality of side edges, the tubular support members
having a first end, a second end, and a sidewall extending there
between. The drain structure panels further include at least one
strut extending from each support member to another support member
to latterly support the tubular support members. An anchor plate is
positioned between at least two tubular support members. The anchor
plate has an aperture formed there through sized and configured to
receive a ground anchoring member for securing the drain structure
panel to a ground surface.
Inventors: |
Blackwood; Charles R.;
(Oklahoma City, OK) |
Correspondence
Address: |
DUNLAP CODDING, P.C.
PO BOX 16370
OKLAHOMA CITY
OK
73113
US
|
Assignee: |
Airfield Systems, L.L.C.
|
Family ID: |
42934509 |
Appl. No.: |
12/420592 |
Filed: |
April 8, 2009 |
Current U.S.
Class: |
405/36 |
Current CPC
Class: |
E02B 11/00 20130101;
E03F 1/002 20130101 |
Class at
Publication: |
405/36 |
International
Class: |
E02B 11/00 20060101
E02B011/00 |
Claims
1-5. (canceled)
6. A drain structure panel for a subsurface drainage assembly,
comprising: a plurality of spaced apart tubular support members
arranged to define a unit having a plurality of side edges, the
tubular support members having a first end, a second end, and a
sidewall extending there between; at least one strut extending from
each support member to another support member to latterly support
the tubular support members; an anchor plate positioned between and
connected to at least two tubular support members, the anchor plate
having an aperture formed there through; and a ground anchoring
member extending through the aperture of the anchor plate and into
a ground surface so as to secure the drain structure panel to the
ground surface.
7. The drain structure panel of claim 6, wherein the anchor plate
extends between and connects at least four adjacent tubular support
members.
8. The drain structure panel of claim 7, wherein the aperture of
the anchor plate is positioned an equal distance between the four
tubular support members.
9. The drain structure panel of claim 6, wherein the anchor plate
is in a coplanar relationship with the struts.
10. The drain structure panel of claim 7, wherein the struts and
the anchor plate extend from the first end of the tubular support
members.
11. The drain structure panel of claim 6, wherein the ground
anchoring member includes an elongated shaft having a first end, a
second end having an enlarged head, and a washer, wherein when the
first end of the elongated shaft is inserted through the aperture
of the anchoring member and driven into the ground surface, the
washer is disposed between the enlarged head of the elongated shaft
and the anchor plate to secure the drain structure panel to the
ground surface.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to systems for
subsurface fluid drainage, and more particularly, but not by way of
limitation, to a subsurface drainage system and a drain structure
therefor which promotes rapid infiltration of water through a
subsoil structure.
[0003] 2. Brief Description of Related Art
[0004] Adequate drainage is a key to maintaining quality turf on
athletic playing fields, such as football and soccer fields,
baseball diamonds, golf courses, and the like. Further, well
drained playing fields eliminate or significantly decrease the time
during which heavy precipitation would make the field
unuseable.
[0005] Previous efforts have been made in the field of subsurface
drainage systems for sports fields and the like. For example, U.S.
Pat. No. 5,848,856 has been issued to William Bohnhoff. The
Bohnhoff '856 patent discloses a subsurface drainage system that
includes a base layer having a sloped surface and covered with an
impermeable liner, a drainage collection pipe at the bottom of each
sloped surface, an intermediate layer formed by a drain structure
overlying the impermeable liner, a filter fabric layer, a root zone
layer, and a turf. The drain structure is a thermoplastic mat with
a laterally extensive backing grid having a plurality of
intersecting struts defining grid openings therebetween and a
plurality of spaced cylindrical support members projecting from the
backing grid whereby fluid may flow through the backing grid and
the cylindrical support member.
[0006] Similar drain structures have also been used in the
construction of a variety of surfaces, such as grass covered
driveways, roads and parking lots, as well as gravel covered
parking lots, driveways, and trails. The drain structure functions
to stabilize particulate materials, including soil, sand, gravel,
and asphalt, and thereby reduce erosion while also supporting the
weight of vehicular and pedestrian traffic to prevent the creation
of ruts in the surface.
[0007] While use of the drainage structure, like that described
above, have met with success, the transportation of such drain
structures can be expensive, and its installation tedious and time
consuming. The present invention is directed to a subsurface
drainage system and drain structure therefor that overcome the
problems of the prior art.
BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWINGS
[0008] FIG. 1 is a sectional view of a subsurface drainage system
constructed in accordance with the present invention.
[0009] FIG. 2 is a top plan view of a drain structure panel
constructed in accordance with the present invention.
[0010] FIG. 2A is a top plan view of a portion of a plurality of
drain structure panels shown linked together.
[0011] FIG. 3 is a top plan view of a tubular member of the drain
structure of FIG. 2.
[0012] FIG. 4 is a cross-sectional view taken along line 4-4 of
FIG. 3.
[0013] FIG. 4A is a side elevational view of a portion of the
support member.
[0014] FIG. 5 is a sectional view of a pair of support members
shown nested relative to one another.
[0015] FIG. 6 is a side elevational view of a portion of a
plurality of drain structures shown nested relative to one
another.
[0016] FIG. 7 is a sectional view of another embodiment of support
members shown nested relative to one another.
[0017] FIG. 8 is a perspective view of a portion of a pair of drain
structure panels illustrating a male connector and a female
connector.
[0018] FIG. 9 is a perspective view of a portion of a pair of drain
structure panels illustrating a male connector and a female
connector.
[0019] FIG. 10 is a perspective view of a portion of a pair of
drain structure panels illustrating a male connector and a female
connector.
[0020] FIG. 11 is a partial top plan view of an alternative
embodiment of a drain structure panel constructed in accordance
with the present invention.
[0021] FIG. 12 is a top plan view of the alternative drain
structure panels shown in FIG. 11 in association with a plurality
of fasteners.
[0022] FIG. 13A is a front elevational view of the fastener for use
with the alternative drain structure panel of FIG. 11.
[0023] FIG. 13B is a perspective view of the fastener of FIG.
13A.
[0024] FIG. 14 is a cross sectional view of the alternative drain
structure panel of FIG. 11 taken along the line 14-14 of FIG. 12,
in association with the fastener of FIGS. 13A and 13B.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Referring now to the drawings, and more particularly to FIG.
1, shown is a subsurface drainage system 10 constructed in
accordance with the present invention. The subsurface drainage
system 10 includes a base layer 12, an impermeable liner 13, a
drain structure 14, a semi-permeable filter fabric layer 16, a root
zone layer 18, and a turf layer 20 defining a playing surface 21.
In instances where it is desirable to allow some permanent deep
infiltration of surface drainage, the impermeable liner 13 may be
replaced with a semi-permeable geotextile fabric or the drain
structure 14 placed directly on the base layer 12.
[0026] The subbase 12 typically includes a subsoil that has been
graded and packed to predetermined slope to direct by gravity the
movement of subsurface water. The subbase 12 is sloped preferably
from about one degree to about fifteen degrees to induce downhill
water flow. A perforated collector pipe 24 preferably is installed
at the down slope terminus of each sloped portion of the subbase
12. The subbase 12 may be graded to define a broad V-shaped basin
with the collector pipe 24 at the bottom thereof so that water
drains down opposing sides of the basin toward a common collection
point at the bottom of the basin. The invention is not limited to
such a configuration, however, and any of a wide variety of sloped
subbase arrangements may be used. The area of the subbase 12 will
generally correspond to the area of the playing surface 21.
[0027] Liquid infiltrating the turf layer 20 percolates downward by
the force of gravity through the root zone layer 18 and the filter
fabric layer 16 and then encounters the drain structure 14. The
liquid flows freely downhill through and along the drain structure
14 until reaching a collection point at the bottom of the sloped
surfaces of the subbase 12, where it enters the perforated
collector pipe 24 beneath the drain structure 14 and below the
grade of the subbase 12. The collector pipe 24 is pitched to
provide drainage there along so that the collected liquid may be
discharged or collected in a container (not shown) for treatment,
off-site disposal, or re-use.
[0028] As will be described in greater detail below, the drain
structure 14 will generally have an a real size that corresponds to
the a real size of the playing surface 21 and provides a permanent
layer of subsurface air space or void through which large volumes
of fluid may rapidly move. The impermeable liner 13 is positioned
between the drain structure 14 and the subbase 12. The filter
fabric layer 16 is disposed on the top surface of the drain
structure 14 and acts to prevent migration of medium that makes up
the root zone layer 18 into the drain structure 14. The root zone
layer 18 is deposited to a suitable depth. The entire surface at
the top of the root zone layer 18 may then be graded as desired to
provide the desired playing surface 21 and the turf layer 20 laid
on the root zone layer 18.
[0029] It will be appreciated that while the turf layer 20 in FIG.
1 represents natural turf, the turf layer 20 may also be artificial
turf. In which case, the root zone layer 18 would typically be
eliminated and the artificial turf layer placed directly on the
filter fabric layer 16.
[0030] Depending upon the size and shape of the surface to be
drained, and upon the graded configuration and number of sloped
surfaces of the subbase 12, a plurality of collector pipes 24 may
be networked according to known hydraulic principles to channel and
direct into a trunk collector pipe the liquids gathered and drained
from the drain structure 14.
[0031] Referring now to FIG. 2, a top plan view of a drain
structure panel 30 is illustrated. The drain structure panel 30 is
utilized in the construction of the drain structure 14 of FIG. 1.
The drain structure 14 is assembled from a plurality of interlinked
drain structure panels 30. While FIG. 1 shows a portion of a single
drain structure panel 30, it is understood that in the ordinary
practice of the invention a plurality of drain structure panels 30
are interconnected in two lateral dimensions, the plurality of
panels 30 thus comprising the drain structure 14.
[0032] Each drain structure panel 30 preferably is composed of
injection-molded plastic, such as high-density polyethylene or
polypropylene. Drain structure panels 30 manufactured from
low-density polyethylene are also applicable in situations where
reduced cost or increased flexibility are desired. Certain elements
of each drain structure panel 30 are designed and manufactured to
have an inflexible rigidity that provides structural strength to
the drain structure 14, yet other portions of each drain structure
panel 30 are shaped to be flexible to permit easy rolling,
transportation, manipulation, and placement of the drain structure
panels 30 for installation and/or assembly. More specifically, each
drain structure panel 30 includes a backing grid 32 and a plurality
of spaced support members 34 projecting from the backing grid 32.
Certain support members are labeled 34 in FIG. 2, but it is readily
understood that a given panel includes a number of other identical
support members. The backing grid 32 which is made from a plurality
of struts 33 provides flexibility to the overall drain structure
panel 30, while the support members 34 provide desired compression
strength.
[0033] The support members 34 lend integrity and strength to the
drain structure panel 30. The backing grid 32 is moderately
flexible in a direction perpendicular to the plane of the drain
structure panel 30, interconnects the support members 34, and
maintains the support members 34 in a spaced-apart relation to each
other. As shown in FIG. 2, the support members 34 are uniformly
arrayed horizontally in perpendicular rows and columns. As shown in
FIGS. 2-4, the support members 34 are fashioned in the form of
tapered, four-leaf clover shaped rings, but it will be appreciated
that support members of other than clover shape may be used in the
invention. Support members 34 having circular, hexagonal, square,
rectangular, or other cross-sectional shapes may be utilized.
However, the support members 34 preferably are generally tubular so
that water, air, and other fluids may flow freely through the
support members 34. Also, the support members 34 need not be
arrayed in perpendicular rows and columns, because circular,
random, or other arrays may function within the scope of the
invention. The support members 34 are preferably of a uniform
height, and thus serve to define the overall thickness of the drain
structure panel 30, which may be, by way of example, approximately
1.0 inch.
[0034] The support members 34 are preferably molded integrally with
the backing grid 32 so that the drain structure panel 30 is further
characterized as having a first side 36, a second side 38, a third
side 40, and a fourth side 42. A series of horizontal struts 33a,
vertical struts 33b, and diagonal struts 33c are shown extending
between adjacent support members 34. In a preferred embodiment, the
struts 33 extend from one support member 34 to another support
member 34 without intersecting another strut 33, thereby reducing
the amount of material used to form the backing grid 32 and
increasing flow area. However, the struts 33 may be formed in a
variety of arrangements, including intersecting arrangements, to
alter the strength and flexibility of the drain structure panel 30,
as well as the size of the grid openings defined between the struts
33 and the support members 34.
[0035] The drain structure panel 30 is generally flat with a
constant thickness, and defines two substantially parallel planes,
one plane containing the backing grid 32 and the other plane
generally defined by the opposing ends of the support members 34.
Advantageously, fluids may freely flow through the grid openings
between struts 33. Also, the integration of the support members 34
with the backing grid 32 maintains adjacent support members 34 in a
spaced-apart relation, leaving ample space through which fluids may
flow.
[0036] Referring now to FIGS. 3 and 4, the support members 34 are
characterized as having a first end or upper end 44 connected to
the backing grid 32, a second end or lower end 46 opposite the
first end 44, and a sidewall 48 extending therebetween. To
facilitate fluid flow through the support members 34 when the
second end 46 of the support members 34 are engaged with the
impermeable liner 13, each of the support members 34 is provided
with a plurality of openings 49 (best shown in FIGS. 3 and 4)
formed through the sidewall 48 on the second end 46 of the support
members 34 and a plurality of openings 50 (best shown in FIGS. 3
and 4) formed through the sidewall 48 on the first end 44 of the
support members 34. While four openings are shown formed in the
first end 44 and four openings are shown in the second end 46, it
will be appreciated the number of openings, as well as the position
of the openings, may be varied. For example, the support members 34
may be formed with only one opening in the first end 44 and the
second end 46. In such case, the drain structure 14 would
preferably be positioned on the subbase 12 with the opening
positioned on the downhill side of the subbase 12 to promote the
drainage of fluid there through.
[0037] The openings 49 are preferably rounded or arch shaped to
eliminate stress risers and sized to permit fluid to flow freely
therefrom when the second ends 46 of the support members 34 are
engaged with the impermeable liner 13. Additionally, each of the
openings 49 defines two corners 51 and 52 with the second end 46 of
the support member 34. The corners 51 and 52 are rounded to a
sufficient radius to provide a smooth, non-jagged transition from
the second end 46 to the openings 49 which will prevent the
impermeable liner 13 from being cut, torn, or punctured while the
drain structure 14 is positioned on the impermeable liner 13 during
the installation process, and in turn loaded with the weight of the
root zone layer 18 and the turf layer 20, as illustrated in FIG. 1.
In addition, the rounded corners 51 and 52 facilitate movement of
the drain structure 30 over the impermeable liner 13 and relative
to another drain structure panel 30 in a manner to be discussed
below.
[0038] Likewise, the openings 50 are preferably rounded or arch
shaped to eliminate stress risers and sized to permit fluid to flow
freely therefrom when the first ends 44 of the support members 34
are engaged with the impermeable liner 13. Additionally, each of
the openings 50 define two corners with the first end 44 of the
support member 34. The corners are rounded in a manner described
above in reference to the openings 49 to a sufficient radius to
provide a smooth, non-jagged transition from the second end 44 to
the openings 50 which will prevent the impermeable liner 13 from
being cut, torn, or punctured when the first end 44 of the drain
structure panels 34 are positioned on the impermeable liner 13
during the installation process, and in turn loaded with the weight
of the root zone layer 18 and the turf layer 20. In addition, the
rounded corners of the openings 50 facilitate movement of the drain
structure 30 over the impermeable liner 13 and relative to another
drain structure panel 30 in a manner to be discussed below.
[0039] As described above, the backing grid 32 is moderately
flexible in a direction perpendicular to the plane of the drain
structure panel 30. Such flexibility permits a row of
interconnected drain structure panels 30 to be rolled on a spindle
(not shown) for storage and transport. While storing and
transporting the drain structure panels 30 in a rolled form permits
quick and easy installation, shipping costs are increased due to
the amount of space occupied by a row of rolled drain structure
panels 30. To reduce space requirements, the support members 34 are
tapered (FIG. 4) from the first end 44 to the second end 46 to
permit the support members 34 of one drain structure panel 30 to be
nested in the support members 34 of another drain structure panel
30 and in turn form a stack of drain structure panels, as shown in
FIG. 6.
[0040] To facilitate removal of one drain structure panel 34 from
an adjacent drain structure panel 34 during the installation
process, the support members 34 are formed to have a plurality of
stop members 54 formed as a step on the interior surface of the
support members 34. The stop members 54 are positioned to engage
the second end 46 of the nested support member 34 to prevent the
nested support member 34 from becoming wedged in the adjacent
support member 34. The support member 34 is shown to have four stop
members 54, but it will be appreciated that any number of stop
members may be formed so long the support members 34 are prevented
from wedging too tightly with the adjacent support member 34.
[0041] FIG. 7 shows another embodiment of a support member 34
having stop member 56 formed as a shoulder on the exterior surface
of the support members 34. The stop members 56 are positioned to
engage the first end 44 of the support member 34 in which the
support member 34 is nested to prevent the nested support member 34
from becoming wedged in the adjacent support member 34. The support
member 34 is shown to have two stop members 56, but it will be
appreciated that any number of stop members may be formed so long
the support members 34 are prevented from wedging too tightly with
the adjacent support member 34.
[0042] To increase rigidity of the second end 46 of the support
members 34, each of the support members 34 is provided with at
least one internal strut 59 traversing the second end 46 of the
support member 34. In the embodiments illustrated herein, the
support members 34 are provided with four struts 59. Each of the
struts 59 extends from one side of a clover leaf to an opposing
side of the clover leaf spaced a distance from the distal end of
the clover leaf. However, the struts 59 may be formed in a variety
of arrangements, including intersecting arrangements, to alter the
strength and flexibility of the support members 34.
[0043] Referring now to FIGS. 2, 2A, and 8-10, a plurality of drain
structure panels 30 are secured together to form the drain
structure 14 of a desired size. To permit attachment between
adjacent drain structure panels 30, complimentary sets of male and
female fasteners are formed on the side edges of each drain
structure panel 30. In the illustrated embodiment, the female
fasteners are fashioned in the form of sockets 60 and 61 formed
along the first and fourth sides 36 and 42, respectively, and the
male fasteners are fashioned in the form of pins 62, 62a, and 63
formed along the second and third sides 38 and 40, respectively, so
that the pins 62 and 62a are disposed opposite the sockets 60 and
pins 63 are disposed opposite the sockets 61.
[0044] The sockets 60 of the female fasteners are defined by a
first end 66, a second end 68 opposite the first end 66, a first
side 70, and a second side 72 opposite the first side 70. The first
end 66, the first side 70, and the second side 72 are closed to
define the socket 60. The second end 68 is open to permit the pin
62 and 62a of the male fastener to be laterally inserted into the
socket 60 from a grid opening 74. The first and second sides 70 and
72 are provided with retaining tabs 76 extending inwardly into the
socket 60 near the second end 68 of the socket 60 to permit the
pins 62 to be snapped into the socket 60 and in turn hold the pins
62 of the male fastener in the socket 60.
[0045] The pins 62 include a shaft 64 and a retaining flange 64a.
The shaft 64 is provided with a sufficient width to slidingly
engage the retaining tabs 76 and thereby snap into the socket 60.
The retaining flange 64a provides a vertical connection to the
socket 60 upon the pin 62 being positioned in the socket 60.
Preferably, the shaft 64 is provided with a sufficient length so
that the retaining flange 64a extends below the socket 60 when the
pin 62 is being positioned into the socket 60.
[0046] The pins 62a may be identical in construction to the pins
62. However, to reduce the force required to connect one drain
structure panel 30 to another drain structure panel 30, the pins
62a may be constructed so that the pins 62a do not snap into the
sockets 60, but instead slide into the sockets 60 in a
non-interference manner. The pin 62a is shown in FIG. 9 to have a
wedge shape leading edge 77 to facilitate movement of the pin 62a
into the sockets 60 during the connecting process. To provide a
vertical connection, the distal end of the pin 62a may include an
inwardly extending portion 77a so as to define a hook. The inwardly
extending portion 77a is spaced a distance from the proximal end of
the pin 62a to define a recess 77b sized to receive at least a
portion of the first end 66 of the socket 60.
[0047] In one embodiment, the drain structure panel 30 is formed to
have three pins 62 with one formed on each end of the row of pins
62 and 62a and one pin 62 formed at a medial location. The
remainder of the pins are in the form of the pins 62a. Such an
arrangement provides for a positive connection of one drain
structure panel 30 to another drain structure panel 30 without
requiring the application of a force necessary to overcome the
interference that would be created by the retaining tabs 76 of all
the sockets 60 if all the pins were configured to snap into the
sockets 60. At the same time, the pins 62a provide lateral and
vertical support.
[0048] To connect one drain structure panel 30 to another drain
structure panel 30, the pins 62 and 62a are positioned behind the
sockets 60 in the adjacent grid opening 74 of the backing grid 32.
The drain structure panels 30 are then moved laterally relative to
one another so as to cause the pins 62 to snap into the sockets 60
and the pins 62a to move into the sockets 60. Connecting the drain
structure panels 30 in this manner permits the drain structures
panels 30 to be assembled quickly and easily due to one drain
structure panel 30 merely having to be laid on the adjacent drain
structure panel 30 and moved laterally relative to one another
without requiring each of the pins 62 to be aligned with and
snapped into a corresponding socket 60.
[0049] The sockets 60 are shown to be enlarged relative to the
sockets 60 and thus are not intended to provide a positive
connection with the pins 63 formed along the third side 40 of the
drain structure panel 30. Instead, the pins 63, which are shown to
be substantially identical in construction to the pins 62a
described above, are designed to be quickly and easily positioned
in the sockets 61 to provide lateral and vertical support. As such,
a row of drain structure panels 30 which have been connected using
the pins 62 and 62a and the sockets 60 may be quickly and easily
interconnected to a parallel row of drain structure panels by
vertically inserting the pins 63 of one row of drain structure
panels in the sockets 61 of the adjacent row of drain structure
panels. More specifically, the drain structure panels 30 are
preferably assembled in a rowed pattern. Staggering of rows will
allow for multiple row completion by a multi-manned crew. A first
row is formed in the manner described above by securing a series of
drain structure panels 30 by inserting the pins 62 and 62a behind
the sockets 60 in the adjacent grid opening 74 of the backing grid
32. The drain structure panel 30 is then pulled so as to move the
drain structure panel 30 laterally and cause the pins 62 to snap
into the sockets 60 and the pins 62a to move into the sockets 60.
After each one directional pull secures adjacent drain structure
panels 30 together.
[0050] Once the first row has progressed, an adjacent second row
may be formed. The second row is initiated by positioning the pins
63 in the sockets 61 of the first drain structure panel 30 of the
adjacent row. Next, the pins 62 and 62a of another drain structure
panel 30 are positioned behind the sockets 60 in the adjacent grid
opening 74 of the backing grid 32 of the first drain structure
panel 30 of the second row. The drain structure panel 30 is then
pulled so as to move the drain structure panel 30 laterally and
cause the pins 62 to snap into the sockets 60 and the pins 62a to
move into the sockets 60 in a manner similar to that used to
assemble the first row. The drain structure panel 30 is then
lowered so as cause the pins 63 to be received in the sockets 61 of
the adjacent drain structure panels 30. The drain structure panels
30 are interconnected in this manner until the desired coverage is
achieved.
[0051] The female fasteners are shown to be formed a distance below
the upper end 44 of the tubular support member 34 while the male
fasteners are shown to extend from the upper end 44. As such, the
male fasteners will remain flush with the upper end 44 of the
support members 34 and the struts 33 when the male fastener is
connected to the female fasteners.
[0052] During the process of installing the drain structure 14, the
drain structure panels 30 are often exposed to radiant heat from
the sun. The heat may in turn cause the drain structure panels 30
to expand. Such expansion will cause the drain structure 14 to
buckle if adjacent drain structure panels 30 are not able to move
relative to one another. In addition, when used with artificial
turf, the artificial turf is generally placed on the drain
structure 14 with only a filter fabric separating the artificial
turf from the drain structure 14. It is well know that artificial
turf tends to absorb heat energy which in turn is transferred to
the drain structure 14. The heating of the drain structure 14 can
again lead to buckling of the drain structure 14. However, in the
case of artificial turf can also lead to buckling of the playing
surface.
[0053] To permit movement of one drain structure panel 30 relative
to an adjacent drain structure panel 30, the sockets 60 and 61 are
shaped to permit compressional and extensional movement of one
drain structure panel 30 relative to the adjacent drain structure
panels 30 when the drain structure panels 30 are secured to one
another. FIGS. 8 and 9 show the socket 60 having a rectangular
configuration which allows the pins 62 and 62a to slide along the
length of the sockets 60, even after the pins 62 and 62a have been
positioned in the sockets 60. By way of example, the pin 62 may
have a thickness of approximately 0.25 inches while the socket 60
may have a length of approximately 0.3750 to 1.00 inches. FIG. 10
shows the socket 61 having a square configuration which allows the
pins 63 to slide within the sockets 61. While the sockets 60 and 61
have been illustrated as having a square or rectangular
configuration, it will be appreciated that the sockets may be
formed to have other configurations which would result in a secure
attachment while permitting relative movement.
[0054] To provide a reference indicator and thereby facilitate
construction of the drain structure 14, the drain structure panel
30 is provided with a generally U-shaped extension member 80 that
extends outwardly from one corner of each drain structure panel 30.
The extension member 80 is shown extending from the corner formed
by the intersection of the second side 38 and the forth side 42.
During the process of assembling the drain structure 14, the
extension member 80 of each drain structure panel 30 will be
oriented in the same direction so that corresponding male and
female fasteners can be quickly aligned and interconnected. The
extension member 80 may be painted or otherwise colored in a manner
that distinguishes the extension member 80 from the remainder of
the drain structure panel 30. Furthermore, while the reference
indicator has been shown to be the extension member 80, it should
be understood that the reference indicator may take many different
forms, including, for example, a colored or non-colored mark on the
backing grid 32 or one or more of the support member 34, so long as
an individual can quickly discern the reference indicator during
the assembly process.
[0055] The high volume capacity and fluid transmissivity of the
drain structure 14 provides a reliable means for circulating heated
or other treated fluids throughout the subsurface. Heated air, for
example, can be pumped into one edge of the drain structure 14 and
withdrawn from another edge, allowing the heat to rise to, for
example, an overlying football field in cold climates. Coupled with
the use of an insulated field blanket, this feature of the drain
structure 14 can extend the turf growing season for the field, and
improve field conditions during snow storms. Alternatively or
additionally, small diameter pipe networks may be installed in the
drain structure 14 between the support structures 34 of the drain
structure panels 30 to provide subsurface heating or cooling.
[0056] The installation of the drainage system 10 is briefly
described again with reference to FIG. 1. The subbase 12 is graded
according to methods and designs known in the art to define one or
more surfaces sloping down to points or lines of fluid collection,
that is, points toward which fluids flow upon the subbase's sloping
surfaces. The subbase 12 preferably is packed to about 95% modified
proctor density. The impermeable liner 13, or, alternatively, a
semipermeable geotextile layer, such as a polyester spunbond
non-woven fabric, is placed directly upon the subbase 12 to conform
to its profile. The perforated collector pipe 24 is installed in a
trench cut into the subbase 12, generally along each collection
point at the bottom of each sloping surface of the subbase 12.
Multiple collector pipes 24 are interconnected, as needed, to
define a collector pipe network through which water will flow by
gravity. The trench containing the collector pipe 24 is then
backfilled with small gravel to the grade of the subbase 12.
[0057] After the installation of the collector pipe 24, optional,
but desirable, systems are placed. Examples include an irrigation
distribution system and risers, and/or heat distribution manifolds
for connection to the drain structure 14 or to a pipe network to be
placed within the drain structure 14. Also, foundations for such
surface structures such as goal posts, bleachers, stages, and the
like are placed.
[0058] Generally, the backing grid 32 of the drain structure panels
30 is placed face up, towards the ground surface and away from the
subbase 12, to provide a smooth profile upon which to lay the
semi-permeable filter fabric layer 16, and the openings 49 of the
support members 34 are placed adjacent the impermeable liner 13 to
foster fluid escape from the support members 34. The flexibility of
the backing grid 32 permits the drain structure 14 to bend and flex
to adapt to the overall contour and profile of the underlying
subbase 12, yet the rigidity of the support members 34 maintains
the uniform thickness of the drain structure 14.
[0059] The semi-permeable filter fabric layer 16, such as a
polyester spunbond non-woven fabric, is next placed upon the drain
structure 14 using shingle-overlapped joints. The widest roll of
fabric preferably is used to minimize joints, and all joints may be
secured with a suitable tape or similar fastener to prevent small
particle intrusion through the semi-permeable filter fabric layer
and into the drain structure 14.
[0060] The root zone layer 18 is then placed upon the filter fabric
layer 16. It will be appreciated that the root zone layer 18 may
vary in depth and composition. However, by way of example, the root
zone soil layer 18 may be placed to a depth of from about eight
inches to about eighteen inches. Furthermore, the root zone layer
18 will typically include a mixture of sand, organic matter, and
inorganic matter in a ratio that will allow a water infiltration
rate of about four inches to six inches per hour. The root zone
layer 18 is topped with the turf layer 20 or other landscaping
media.
[0061] The drain structure 14 has been described above for use in
facilitating the drainage of water from a playing field, such as a
football field or a golf putting green. It should be appreciated,
however, that the drain structure 14 described herein may also be
used to stabilize particulate materials, such as soil, sand,
gravel, and asphalt, used in the construction of a variety of
surfaces, such as grass covered driveways, roads and parking lots
and gravel covered parking lots, driveways, and trails. The drain
structure 14 helps prevent erosion and supports the weight of
vehicular and pedestrian traffic. When used to stabilize
particulate materials, the drain structure 14 is typically
installed grid side down directly onto a subbase or base layer. A
selected particulate material is then spread over the drain
structure 14 so that the particulate material fills the support
members 34 of the drain structure 14. The particulate material is
then compacted or sod or seed is spread over the drain structure
14.
[0062] Referring now to FIGS. 11, 12 and 14 collectively, shown
therein is an alternative embodiment of a drain structure panel
130. The drain structure panel 130 is constructed similarly to the
drain structure panels 30 disclosed above with the addition of
anchor plates and ground anchoring members. Examples of the anchor
plates and ground anchoring members are described hereinafter.
[0063] Similarly to the drain structure panel 30, the drain
structure panel 130 includes a backing grid 132 and a plurality of
spaced support members 134 projecting from the backing grid 132.
Certain support members are labeled 134 in FIG. 11, but it is
readily understood that a given panel includes a number of other
identical support members. The backing grid 132 which is made from
a plurality of struts 133 provides flexibility to the overall drain
structure panel 130, while the support members 134 provide desired
compression strength.
[0064] The support members 134 are characterized as having a first
end or upper end 144 connected to the backing grid 132, a second
end or lower end 146 opposite the first end 144, and a sidewall 148
extending therebetween (see FIG. 14). In this embodiment, the
support members 134 are provided as four-leaf clover shaped rings,
but it will be appreciated that support members other than clover
shaped may be used in the invention. Support members 134 having
circular, hexagonal, square, rectangular, or other cross-sectional
shapes may be utilized. Additionally, to increase rigidity of the
second end 146 of the support members 134, each of the support
members 134 may be provided with at least one internal strut 159
traversing the second end 146 of the support member 134.
[0065] To permit attachment between adjacent drain structure panels
130, complimentary sets of male and female fasteners may be formed
on the side edges of each drain structure panel 130. In one
embodiment, the female fasteners of the drain structure panels 130
are fashioned similarly to the female fasteners of the drain
structure panels 30 with the exception that the drain structure
panel 130 is provided with sockets 160 formed along the first and
fourth sides 162 and 164, respectively, such that the drain
structure panels 130 are provided with only one type of socket 160
rather than two different sockets 60 and 61 as shown in FIG. 2A.
The male fasteners are fashioned in the form of pins 166 formed
along the second and third sides 168 and 170, respectively, so that
the pins 166 are disposed opposite the sockets 160. It will be
understood that the drain structure panels 130 may also have two
separate sizes of sockets 160 and pins 166 constructed similarly to
the drain structure panels 30.
[0066] To permit the drain structure panel 130 to be anchored to
the subbase 12 or base layer, particularly when the drain structure
panel 130 is used to stabilize particulate matter, the drain
structure panel 130 is provided with one or more anchor plates 172.
The anchor plates 172 are formed integrally with the drain
structure panel 130 and are therefore fabricated from, for example,
an injection-molded plastic, such as high-density polyethylene or
polypropylene. In one embodiment, the anchor plates 172 are
substantially square shaped plates having a uniform thickness. In
one embodiment the anchor plates 172 are disposed between and
connect two adjacent support members 134. In another embodiment one
of the anchor plates 172 is connected to one of the clovers of each
of four separate but adjacent support members 174, 176,178, and
180. The anchor plates 172 may be spaced apart from one another in
a predetermined pattern along the drain structure panel 130.
Furthermore, the anchor plates 172 may be connected to either the
first ends 144 or the second ends 146 of the adjacent support
members 174, 176, 178, and 180.
[0067] Referring now to FIGS. 11-14 collectively, in one
embodiment, the anchor members 172 each include one or more
apertures 182 constructed to receive a ground anchoring member 184
(see FIGS. 13A and 13B) therethrough for anchoring the drain
structure panel 130 to the subbase 12. It will be understood that
the shape, size and number of apertures 182 may be dictated by the
shape, size and number of ground anchoring members 184 used.
Additionally, each aperture 182 may be located equadistantly from
the apexes of the clover leaves such that the aperture 182 is
positioned in the center of the anchor plate 172 to provide
sufficient clearance for the insertion of the ground anchoring
member 184. Providing sufficient clearance for the insertion of the
ground anchoring member 184 reduces the likelihood of incidental
damage to the support members 134 when the ground anchoring member
184 is installed. In one embodiment, the ground anchoring member
184 may include an elongated shaft 188 having an enlarged head 190
and a washer 192 sized to slidably engage the elongated shaft
188.
[0068] In use, a plurality of drain structure panels 130 are
arranged to form a drain structure (not shown). More specifically,
the backing grid 132 of a first drain structure panel 130 is placed
grid-side down, abutting the subbase 12 or a base layer. To anchor
the first drain structure panel 130 in place, one or more ground
anchoring members 184 are inserted into the apertures 182 of the
one or more anchor plates 172 of the first drain structure panel
130. The ground anchoring members 184 are driven into the subbase
12 until the enlarged head 190 of the elongated shaft 188 engages
the washer 192. Additional drainage structure panels 130 may be
placed adjacent to the first drainage structure panel 130 and
likewise anchored to the subbase 12 to form the drain structure
(not shown). In addition, the additional drainage structure panels
130 may be connected to the first drainage structure panel 130 and
to one another in the manner described above.
[0069] From the above description, it is clear that the present
invention is well adapted to carry out the objects and to attain
the advantages mentioned herein, as well as those inherent in the
invention. While a presently preferred embodiments of the invention
have been described for purposes of this disclosure, it will be
understood that numerous changes may be made which will readily
suggest themselves to those skilled in the art and which are
accomplished within the spirit of the invention disclosed and as
defined in the appended claims.
* * * * *