U.S. patent application number 11/200308 was filed with the patent office on 2006-02-09 for subsurface drainage system.
Invention is credited to Charles F. Blackwood, Charles R. Blackwood, James M. Courter.
Application Number | 20060029472 11/200308 |
Document ID | / |
Family ID | 35757574 |
Filed Date | 2006-02-09 |
United States Patent
Application |
20060029472 |
Kind Code |
A1 |
Blackwood; Charles R. ; et
al. |
February 9, 2006 |
Subsurface drainage system
Abstract
The present invention is directed to a subsurface drainage
system for a playing surface. The subsurface drainage system
includes a subgrade, an intermediate layer disposed over the
subgrade, a layer of semi-permeable filter fabric disposed over the
intermediate layer, an upper permeable layer disposed over the
layer of filter fabric and on which the playing surface is
disposed, and a hydronic piping network disposed in the upper layer
near the layer of filter fabric. The layer of filter fabric has a
permeability less than the permeability of the intermediate layer
and such that the layer of filter fabric functions as a perching
layer to support a perched water table above the filter fabric. The
hydronic piping network is positioned within the perched water
table such that the water of the perched water table functions as a
heat exchanger to facilitate heating and cooling of the upper layer
upon the hydronic piping network being heated or cooled.
Inventors: |
Blackwood; Charles R.;
(Oklahoma City, OK) ; Courter; James M.; (Edmond,
OK) ; Blackwood; Charles F.; (Oklahoma City,
OK) |
Correspondence
Address: |
DUNLAP, CODDING & ROGERS P.C.
PO BOX 16370
OKLAHOMA CITY
OK
73113
US
|
Family ID: |
35757574 |
Appl. No.: |
11/200308 |
Filed: |
August 8, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60600095 |
Aug 9, 2004 |
|
|
|
Current U.S.
Class: |
405/36 ;
405/38 |
Current CPC
Class: |
E01C 13/08 20130101;
E02B 11/00 20130101; E01C 13/083 20130101 |
Class at
Publication: |
405/036 ;
405/038 |
International
Class: |
E02B 11/00 20060101
E02B011/00 |
Claims
1. A subsurface drainage system for a playing surface, comprising:
a subgrade; an intermediate layer disposed over the subgrade and
formed from at least one material to define a drainage blanket
layer; a layer of semi-permeable filter fabric disposed over the
intermediate layer, the layer of filter fabric having a
permeability less than the permeability of the intermediate layer
and such that the layer of filter fabric functions as a perching
layer to support a perched water table above the layer of filter
fabric; an upper permeable layer disposed over the layer of filter
fabric and on which the playing surface is disposed; and a hydronic
piping network disposed in the upper layer near the layer of filter
fabric so that the hydronic piping network is positioned within the
perched water table such that the water of the perched water table
functions as a heat exchanger to facilitate heating and cooling of
the upper layer upon the hydronic piping network being heated or
cooled.
2. The subsurface drainage system of claim 1 wherein the layer of
filter fabric is a polyester spunbond non-woven fabric having a
weight in a range of from about 110 gsm to about 150 gsm.
3. The subsurface drainage system of claim 1 wherein the subgrade
is contoured to define one or more surfaces sloping down to points
or lines of fluid collection.
4. The subsurface drainage system of claim 1 wherein the
intermediate layer is formed at least one material selected from
the group consisting of crushed stone, pea gravel, rubber
particles, and combinations thereof.
5. The subsurface drainage system of claim 1 wherein the
intermediate layer is a thermoplastic mat having a laterally
extensive backing grid and a plurality of spaced tubular support
members projecting from the backing grid whereby fluid may flow
through the backing grid and the support members.
6. The subsurface drainage system of claim 1 wherein the upper
layer is a root zone layer comprising at least one material
selected from the group consisting of sand, organic matter,
inorganic matter and combinations thereof.
7. A subsurface drainage system for regulating the temperature of a
root zone, comprising: a semi-permeable filter fabric having a
permeability such that the filter fabric functions as a perching
layer to support a perched water table above the filter fabric; a
root zone layer disposed over the layer of filter fabric; a natural
turf layer disposed on the root zone layer; and a hydronic piping
network disposed in the root zone layer near the layer of filter
fabric with the hydronic piping network positioned within the
perched water table such that the water of the perched water table
functions as a heat exchanger to facilitate heating and cooling of
the root zone layer upon the hydronic piping network being heated
or cooled.
8. The subsurface drainage system of claim 7 wherein the layer of
filter fabric is a polyester spunbond non-woven fabric having a
weight in a range of from about 110 gsm to about 150 gsm.
9. A subsurface drainage system for regulating the temperature of
an artificial turf, comprising: a semi-permeable filter fabric
having a permeability such that the filter fabric functions as a
perching layer to support a perched water table above the filter
fabric; a permeable upper layer disposed over the layer of filter
fabric; an artificial turf layer disposed on the upper permeable
layer; and a hydronic piping network disposed in the upper
permeable layer near the layer of filter fabric with the hydronic
piping network positioned within the perched water table such that
the water of the perched water table functions as a heat exchanger
to facilitate heating and cooling of the upper permeable layer and
thus the artificial turf layer upon the hydronic piping network
being heated or cooled.
10. The subsurface drainage system of claim 9 wherein the layer of
filter fabric is a polyester spunbond non-woven fabric having a
weight in a range of from about 110 gsm to about 150 gsm.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Provisional
Application No. 60/600,095, filed Aug. 9, 2004, which is
incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a subsurface drainage
system for facilitating water drainage from a land surface, and
more particularly but not by way of limitation, to improved
subsurface drainage system for an athletic field, such as a putting
green or football field, which subsurface drainage system is
capable of retaining adequate water to facilitate turf growth and
temperature regulation while promoting rapid infiltration of water
through the subsoil structure.
[0004] 2. Brief Description of Related Art
[0005] Conventionally, drainage for athletic fields, such as
football fields and putting greens, has been constructed with the
use of a network of drain pipe buried under the playing surface.
The drain pipe is provided with a multiplicity of perforations in
the circumferential wall thereof. Rainwater or irrigation water
penetrating into the playing field is introduced into the drainage
pipe through the perforations in the circumferential wall thereof,
collected to a trunk pipe, and drained.
[0006] Today, most playing fields are constructed to have an
intermediate layer comprising gravel and a root zone layer
comprised primarily of sand to promote drainage and thus prevent
root rot of the turf grass. As such, even a small amount of water
rapidly penetrates the root zone layer and passes into the drainage
system. Agricultural chemicals or fertilizers that are used to
maintain or control the grass also flow out together with the
water.
[0007] During warm weather months, watering of natural grass
playing fields is required for growing and maintaining the grass.
With the conventional concentrated drainage system, however, a
putting green having a root mix layer comprised primarily of sand
would require watering at least about twice per day in summer, even
if a water-retaining material such as perlite or pumice is
incorporated as an improving material in the root mix. Such
watering requires time and labor.
[0008] Additionally, temperature variation can cause problems in
maintaining healthy grass for certain temperature sensitive
grasses. To this end, piping networks have previously been
installed in the subsurface in an attempt to regulate the
temperature of the root zone layer. The same is true with respect
to artificial turf surfaces in attempt to maintain a safe playing
surface, one which is not too hot or too cold. The problem
encountered with such piping networks is that it is difficult to
uniformly heat or cool the root zone layer without employing a
dense network of pipes. Obviously, increasing the amount of pipe
used increases the cost of the system. It would be preferred to
obtain a uniform distribution while using a minimum amount of
pipe.
[0009] In view of the above-mentioned concerns, a need exits for a
subsurface drainage system that is capable of retaining adequate
water while promoting rapid infiltration of water through the
subsoil structure and which is adapted to uniform temperature
regulation. It is to such a subsurface drainage system that the
present invention is directed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] FIG. 1 is a schematic sectional view illustrating a
subsurface drainage system for natural turf constructed in
accordance with the present invention.
[0011] FIG. 2 is a schematic sectional view illustrating another
embodiment of a subsurface drainage system for natural turf
constructed in accordance with the present invention.
[0012] FIG. 2A is a top cutaway view of FIG. 2 illustrating a
hydronic piping network for natural turf constructed in accordance
with the present invention.
[0013] FIG. 3 is a schematic sectional view illustrating another
embodiment of a subsurface drainage system for natural turf
constructed in accordance with the present invention.
[0014] FIG. 4 is a schematic sectional view of a subsurface
drainage system for artificial turf constructed in accordance with
the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring now to the drawings, and more particularly to FIG.
1, shown therein is a subsurface drainage system 10 constructed in
accordance with the present invention. The subsurface drainage
system 10 is similar to that recommended by the United States Golf
Association for the construction of putting greens with the
exception that the subsurface drainage system 10 includes a
semi-permeable filter fabric layer at the bottom of the root zone
layer. The 2004 revisions of the USGA Recommendations for a Method
of Putting Green Construction is hereby expressly incorporated
herein by reference. More particularly, the subsurface drainage
system 10 of the present invention includes a subgrade or base 12,
an intermediate layer 14, a semi-permeable filter fabric layer 16,
an upper or root zone layer 18, and a turf layer 20. Optionally, an
impermeable liner 22 is disposed between the base layer 12 and the
intermediate layer 14. In instances where it is desirable to allow
some permanent deep infiltration of surface drainage, the
impermeable liner 22 may be replaced with a semi-permeable
geotextile fabric.
[0016] The base layer 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 (not shown). The base layer 12
should be thoroughly compacted to prevent settling.
[0017] The intermediate layer 14 provides a drainage blanket and is
therefore formed of materials, such as crushed stone, pea gravel,
rubber particles, or combinations thereof. As used herein,
"intermediate layer" means a gravel layer or a gravel layer and an
intermediate layer as those terms are used by the USGA in its
recommendations for a method for constructing a putting green.
[0018] The root zone layer 18 is generally comprised of a
homogenous mixture of sand, organic matter, and inorganic
matter.
[0019] The filter fabric layer 16 is interposed between the
intermediate layer 14 and the root zone layer 18. When a filter
fabric layer 16 is not interposed between the root zone layer 18
and the intermediate layer 14, the sand of the root zone layer 18
can become commingled with the intermediate layer 14 and thereby
effect the permeability of the intermediate layer 14 and the water
retention capacity of the root zone layer 18. The filter fabric
layer 16 will function to prevent particles from the root zone
layer 18 from migrating into the intermediate layer 14, thereby
maintaining the permeability of the intermediate layer 14.
[0020] The permeability of the filter fabric layer 16 is less than
the permeability of the intermediate layer 14. As such, the filter
fabric layer 16 will function to distribute and support a uniform
layer of water above the filter fabric 16 in the form of a perched
water table 24. Because the permeability of the filter fabric 16 is
substantially uniform, the perched water table 24 will have a
substantially uniform height which will promote uniform turf
growth. Furthermore, the permeability of the filter fabric layer 16
should be such that static or un-pressurized water in the root zone
layer 18 is held up by the perching layer, but upon the turf
receiving irrigation water or rainwater, water percolating
downwardly through the root zone layer 18 will increase the water
pressure on the filter fabric layer 16 and thus cause water to flow
freely through the filter fabric layer 16 and the intermediate
layer 14. A suitable material for use as the filter fabric layer is
a polyester spunbond non-woven fabric having a weight in a range of
from about 65 gsm to about 205 gsm, and more preferably in a range
of from about 110 gsm to about 150 gsm.
[0021] It will be appreciated that the thickness and composition of
each of the layers of the subsurface drainage system 10 may be
varied widely depending on factors, such as climate conditions,
availability of materials, and intended use of the turf.
[0022] FIGS. 2 and 2A illustrate another subsurface drainage system
10a which is similar to the subsurface drainage system 10 described
above except that a hydronic piping network 30 is shown disposed in
the root zone layer 18 near the filter fabric layer 16 so that the
hydronic piping network 30 is positioned within the perched water
table 24. By having the hydronic piping network 30 positioned
within the perched water table 24, the water will function as a
heat exchanger to facilitate heating and cooling of the root zone
layer 18. Hydronic piping networks and their components are well
known in the art. Thus, no further description of its components,
construction, or operation is believed necessary in order for one
skilled in the art to understand and implement the subsurface
drainage system 10a of the present invention.
[0023] FIG. 3 shows another embodiment of a subsurface drainage
system 10b constructed in accordance with the present invention.
The subsurface drainage system 10b is similar to that disclosed
above and in U.S. Pat. No. 5,848,856 which is hereby expressly
incorporated herein by reference. The subsurface drainage system
10b includes a base layer 40 having at least one sloped surface 41,
a drainage collection point (not shown) at the bottom of each
sloped surface, and an intermediate layer 42 formed by a drain
structure overlying the base layer 40, a filter fabric layer 44, a
root zone layer 46, and a turf 48.
[0024] The drain structure 42 is a thermoplastic mat with a
laterally extensive backing grid having a plurality of struts 43a
defining grid openings therebetween and a plurality of spaced
tubular support members 43b projecting from the backing grid 43a,
whereby fluid may flow through the backing grid 43a and between the
support members 43b. The filter fabric layer 44 is a semipermeable
geotextile fabric disposed in flush contact upon the drain
structure 42, and preferably, but optionally, an impermeable liner
50 is disposed between the base layer 40 and the drain structure
42. In instances where it is desirable to allow some permanent deep
infiltration of surface drainage, the impermeable liner 50 may be
replaced with a semi-permeable geotextile fabric.
[0025] The subsurface drainage system 10b further includes a
hydronic piping network 52 disposed in the root zone layer 46 near
the filter fabric layer 44 so that the hydronic piping network 52
is positioned within a perched water table 54. By having the
hydronic piping network 52 positioned within the perched water
table 54, the water will act as a heat exchanger to facilitate
heating or cooling of the root zone layer 46, as desired. Hydronic
piping networks are well known in the art. Thus, no further
description of its components, construction, or operation is
believed necessary in order for one skilled in the art to
understand and implement the subsurface drainage system 10b of the
present invention.
[0026] FIG. 4 shows a subsurface drainage system 10c for an
artificial turf 68 constructed in accordance with the present
invention. The subsurface drainage system 10c includes a base layer
60 having at least one sloped surface 61, a drainage collection
point (not shown) at the bottom of each sloped surface 61, and an
intermediate layer 62 formed by a drain structure overlying the
base layer 60, a filter fabric layer 64, an upper layer 66, and the
artificial turf 68. The artificial turf 68 is provided with a
porous backing 69 such as a geotextile fabric or fabric with holes
formed therein to permit drainage therethrough.
[0027] The drain structure 62 is a thermoplastic mat with a
laterally extensive backing grid having a plurality of struts
defining grid openings therebetween, and a plurality of spaced
support members projecting from the backing grid, whereby fluid may
flow through the backing grid and between the support members. An
impermeable liner 70 is disposed between the base layer 60 and the
drain structure 62. In instances where it is desirable to allow
some permanent deep infiltration of surface drainage, the
impermeable liner 70 may be replaced with a semi-permeable
geotextile fabric.
[0028] The upper layer 66 may be formed of sand, gravel, rubber, a
porous pad, or combinations thereof.
[0029] The subsurface drainage system 10c further includes a
hydronic piping network 72 disposed in the upper layer 66 near the
filter fabric layer 64 so that the hydronic piping network 72 is
positioned within the perched water table 74. By having the
hydronic piping network 72 positioned within the perched water
table 74, the water will act as a heat exchanger to facilitate
heating and cooling of the upper layer 66 and thus the artificial
turf 68. Hydronic piping networks are well known in the art. Thus,
no further description of its components, construction, or
operation is believed necessary in order for one skilled in the art
to understand and implement the subsurface drainage system 10c of
the present invention.
[0030] 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.
* * * * *