U.S. patent application number 13/939710 was filed with the patent office on 2013-12-26 for subsurface insulation product and method for installing same.
The applicant listed for this patent is John BANDURA. Invention is credited to John BANDURA.
Application Number | 20130343818 13/939710 |
Document ID | / |
Family ID | 49292424 |
Filed Date | 2013-12-26 |
United States Patent
Application |
20130343818 |
Kind Code |
A1 |
BANDURA; John |
December 26, 2013 |
Subsurface Insulation Product and Method for Installing Same
Abstract
A subsurface thermal insulation product for reducing ground
disturbance during a freeze-thaw cycle comprises: a plurality of
thermal insulation panels each comprising: a foam board and a water
wicking sheet attached to one of the top surface or the bottom
surface of the foam board. Each foam board has a top surface and a
bottom surface and four peripheral shiplap edges each with a notch
that permits multiple thermal insulation panels to be placed in
adjacent overlapping engagement.
Inventors: |
BANDURA; John; (Rocky
Mountain House, CA) |
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Applicant: |
Name |
City |
State |
Country |
Type |
BANDURA; John |
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US |
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Family ID: |
49292424 |
Appl. No.: |
13/939710 |
Filed: |
July 11, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13441236 |
Apr 6, 2012 |
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13939710 |
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Current U.S.
Class: |
404/71 ;
405/130 |
Current CPC
Class: |
E01C 11/245 20130101;
E01C 3/06 20130101; E02D 3/11 20130101 |
Class at
Publication: |
404/71 ;
405/130 |
International
Class: |
E02D 3/11 20060101
E02D003/11; E01C 11/24 20060101 E01C011/24 |
Claims
1-7. (canceled)
8. A method for protecting ground infrastructure on a permafrost
area from permafrost thaw, comprising: (a) covering a permafrost
site with a bedding material such that a uniform surface is formed
over the permafrost site; (b) laying a plurality of thermal
insulation panels over the bedding material, wherein each panel
comprises a foam board, each foam board having a top surface and a
bottom surface and four peripheral shiplap edges each with notch
that permits multiple thermal insulation panels to be placed in
adjacent overlapping engagement; and a water wicking sheet attached
to one of the top surface or the bottom surface of the foam board;
(c) interlocking the panels together such that at least one panel
is interlocked with four other panels around its four peripheral
shiplap edges; and (d) applying a covering material over the
interlocked panels; then (e) installing ground infrastructure over
the covering material.
9. A method as claimed in claim 8 wherein the bedding material is
snow.
10. A method as claimed in claim 8 wherein each panel further
comprises a water repelling sheet attached to the other of the top
surface or bottom surface of the foam board.
11. A method as claimed in claim 8 wherein the ground
infrastructure is gas production equipment on the permafrost
site.
12-13. (canceled)
14. A method of protecting a roadway in a permafrost site from
permafrost thaw, comprising: (a) removing overburden to a level of
permafrost soil; (b) laying a plurality of thermal insulation
panels over the permafrost soil, wherein each panel comprises a
foam board, each foam board having a top surface and a bottom
surface and four peripheral shiplap edges each with a notch that
permits multiple thermal insulation panels to be placed in adjacent
overlapping engagement; and a water wicking sheet attached to one
of the top surface or the bottom surface of the foam board; (c)
interlocking the panels together such that at least one panel is
interlocked with four other panels around its four peripheral
shiplap edges; and (d) covering the interlocked panels with a
selected covering material; then (e) constructing a roadway on the
covering material.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 13/441,236, filed Apr. 6, 2012, the entirety
of which is incorporated by reference herein.
FIELD
[0002] The present invention relates to a subsurface insulation
product that reduces ground disturbance during freeze-thaw cycles,
and a method for installing same to protect a road or other ground
infrastructure.
BACKGROUND
[0003] Freeze-thaw cycles may result in frost heaves or frost
boils, both of which damage roads and other infrastructure, such as
buried utility lines,
[0004] A frost boil is caused by capillary action of water during
freeze-thaw cycles. The capillary action draws dirt long with the
water, creating a subsurface cavity which undermines and leads to
damage and ultimately the collapse of a road.
[0005] A frost heave is caused by absorbent soils. Soils, such as
bentonite clay, are capable of absorbing large amounts of water. As
the water freezes it expands, pushing the soil underlying a road
upwardly and damaging the road.
[0006] One approach to reducing ground disturbances during
freeze-thaw cycles is disclosed in Canadian patent CA 2,377,702.
This patent discloses a method which includes the steps of laying a
subsurface layer of thermal insulation over an affected area,
thereby thermally insulating the affected area from freezing, and
laying a subsurface layer of wick material capable of drawing water
away from the affected area by capillary action parallel to the
subsurface layer of thermal insulation and positioned in a path of
the subsurface flow of water.
[0007] It is desirable to provide improvements to present
approaches of reducing such ground disturbances during freeze-thaw
cycles.
SUMMARY
[0008] According to one aspect of the invention, there is provided
a subsurface thermal insulation product for reducing ground
disturbance during a freeze-thaw cycle. The product comprises a
plurality of interlocking thermal insulation panels. Each panel
comprises a foam board and a water wicking sheet attached to one of
the top surface or the bottom surface of the foam board. Each foam
board has a top surface and a bottom surface and four peripheral
shiplap edges each with a notch that permits multiple thermal
insulation panels to be placed in adjacent overlapping engagement.
The product can also include a water-repelling sheet attached to
the other of the top surface and bottom surface of the thermal
insulation panels; this water-repelling sheet is useful to direct
water away from the panels. Each insulation panel can be composed
of a foam material such as polystyrene. The insulation panel range
from 3''-4'' thick and the notches can extend from the side edges,
i.e. have an overlap of 2.7'' to 3.3'', and in particular have an
overlap of 3''. The ratio of board thickness to overlap can be
between 1.48:1 and 1.21:1 to provide superior breakage
resistance.
[0009] The thermal insulation panels are provided to reduce the
likelihood of freezing in the temperature ranges at which
freeze-thaw cycles normally occur. The wicking sheet is also
provided to draw water away from the affected area by capillary
action. Thus, water is moved away from the affected area so that
there is less likelihood of ground disturbance should the affected
area freeze.
[0010] Although beneficial results may be obtained through the use
of the subsurface insulation product as described above, water
coming from secondary sources (such as an artisian spring) and
other directions can be confined by placing a water repelling sheet
attached-bonded to the other of the top surface or the bottom
surface.
[0011] Although beneficial results may be obtained through the use
of the thermal insulation panel, as described above, when covering
large areas, such as underlying multi-lane highways, it is
difficult to do so using a single panel. It may therefore be
necessary to use multiple panels. However, the object of containing
and redirecting the water could be defeated by water seeping around
the panels. It is, therefore, preferred that the panels have
notches along all four peripheral side edges to enable the
insulation panels to be placed in side by side overlapping
engagement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1(a) and (b) are end elevation views, in section, of a
road having with an affected area which has been repaired with a
subsurface insulation product according to a first embodiment (FIG.
1(a)) and a second embodiment (FIG. 1(b)) of the invention,
respectively.
[0013] FIG. 2 is a perspective view, partially cut away, of a road
and a plurality of insulation panels of the subsurface insulation
product according to the second embodiment.
[0014] FIGS. 3(a) and (b) are exploded bottom end and top end
perspective views of part of the first and second embodiments of
the subsurface insulation product.
[0015] FIGS. 4(a) to (d) are respective top plan, side elevation,
bottom plan, and end elevation views of the insulation panels of
the first and second embodiments of the subsurface insulation
product.
[0016] FIG. 5 is a top perspective of three adjacent insulation
panels of the first and second embodiments of the product.
[0017] FIG. 6 is a detailed top perspective view of connections
between two adjacent insulation panels of the first and second
embodiments of the product.
DETAILED DESCRIPTION
[0018] The embodiments of the invention described herein relate to
a subsurface insulation product used to reduce ground disturbance
of ground infrastructure during a freeze-thaw cycle, and a method
for installing such a product to protect the ground infrastructure.
Examples of ground infrastructure that can be protected by the
insulation product include foundations, surface and subsurface
pipelines, roadways, and sewer lines.
[0019] A first embodiment of the subsurface insulation product
comprising a plurality of interlocking thermal insulation panels 13
is shown in FIG. 1(a) and which is installed under a road located
in a permafrost area. A second embodiment is shown in FIG. 1(b)
wherein the subsurface insulation product includes the thermal
insulation panels 13 and angled wings 24 and which is installed in
an elevated roadway. In both embodiments, each interlocking thermal
insulation panel 13 is generally planar and comprises a foam board
14 with means for interlocking with adjacent insulation panels 13
around all four peripheral edges of the foam board 14, a water
wicking sheet 16 attached to and covering a major surface of each
foam board 14 and that is capable of drawing water away from an
affected area 12 by capillary action, and a water repelling sheet
28 attached to and covering the other major surface of each foam
board 14 and that provides a water incursion barrier. As will be
described in further detail below, the position of the water
wicking sheet 16 and water repelling sheet 28 when installed in the
ground is dependent on the direction in which the water or moisture
originates.
[0020] In the second embodiment shown in FIGS. 1(b) and 2, the
insulation panels 13 are installed under an elevated roadway and
interlock with a plurality of downwardly angled wings 24. The
downwardly angled wings 24 prevent frost penetration from
peripheral edges 26 of the insulation product, When this embodiment
is installed in the manner as shown in these Figures, the panels 13
are oriented so that the water wicking sheets 16 are positioned in
a path of the subsurface flow of water. In this case, the water
wicking sheets 16 are facing upwards and covering the top surface
of the foam board 14 and the water repelling sheets are covering
the bottom surface of the foam board 14. Soil 10 is then replaced
over the water wicking sheets 16. After the soil 10 is replaced,
the affected area 12 can then be repaved with travel surface 18. In
operation, the water wicking sheets draw water originating from the
source of water above the subsurface insulation product 100 and
towards the foam board 14; this water then flows along the foam
board 14 to its edges and then is directed by the water repelling
layer 28 to a drainage area away from the roadway 18.
[0021] The subsurface insulation product will now be described in
greater detail with reference to FIGS. 3(a)-(b) to 5. Both
embodiments of the insulation product comprise panels 13 having a
generally planar thermally insulating foam board 14 sandwiched by
one or more of the water wicking sheets 16 and one or more of the
water repelling sheets 28. In the second embodiment, the product
also includes one or more thermally insulating angled wings 24.
[0022] Each foam board 14 is in the form of a single rigid planar
and rectangular board. The foam board 14 can be composed of high
density expanded polystyrene (EPS), such as the closed cell EPS
foam insulation sheets made by Plasti-Fab.TM. under the trade-mark
PlastiSpan.RTM.. This EPS foam insulation sheet meets or exceeds
the requirements of the Canadian standard CAN/ULC-S701-05 Standard
for Thermal Insulation Styrene, Boards and Pipe Covering. Other
suitable foam sheets include high strength EPS foam insulation
boards manufactured by Beaver Plastics.TM. under the trade-mark
Terrafoam HS-40.RTM. also meets or exceeds CAN/ULC S-701 type 2
standard as well as the ASTM C-578 Type 14 standard by the American
Society for Testing and Materials. Other suitable foam sheets 14
are provided by Dow under the SM.TM. and SM Hi Load.TM.
trade-marks. Alternatively, the foam board 14 can be made from
another insulating foam material such as polyurethane.
[0023] In this embodiment, each foam board 14 is about four feet
(4') wide by eight feet (8') long by four inches (4'') thick;
however, the foam board 14 can be produced in other dimensions
depending on the preferences of the user. For example, the board 14
can be between 3'' to 4'' thick, The foam board 14 has a top
surface 124 and a bottom surface 126 and four notched or "shiplap"
peripheral edges, namely, first and second opposed short shiplap
edges 120, 121, and third and fourth opposed long shiplap edge 122,
123. The first short shiplap edge 120 has a notch extending
outwardly from the bottom half of the edge 120 and along its entire
length. The second short shiplap edge 121 has a notch extending
outwardly from the top half of the shiplap edge 121 and along its
entire length. Similarly, the third long shiplap edge 122 has a
notch extending outwardly from the bottom half of the shiplap edge
122 and along its entire length, and the fourth long shiplap edge
123 has a notch extending outwardly from the top half of the edge
123 and along its entire length. The net impression created by
these four shiplap edges is of two offset sheets that are fused
together, as evident from the Figures, even though the board 14 is
made from a single piece.
[0024] While the foam board 14 is formed by extruding a single
piece of polystyrene material and cutting the four notched shiplap
edges 120, 121, 122, 123 into the board 14 in the configuration
described above, the foam board 14 can be alternatively formed from
a pair of sheets (not shown) joined together in an offset
manner.
[0025] In this embodiment, the notches for the first and second
short shiplap edges 120, 121 and the third and third long shiplap
edges 122, 123 extend 3'' (about 75 mm) outwards and 4 feet along
the length of the respective shiplap edges 120, 121, i.e. has a 3
inch "overlap". This overlap dimension has been found to provide
superior resistance to breakage relative to the material and
dimensions of the sheet 118, particularly the sheet's thickness. It
is expected that an overlap of between 2.7'' and 3.3'' (about 70
and 85 mm) for a 4 inch thick EPS foam board 14 (and each notch
being 1/2 the thickness of the board at 2'') will provide similar
superior breakage resistance. To put it another way, an EPS board
14 should have a ratio of board thickness to overlap of between
1.48:1 and 1.21:1 to provide superior breakage resistance.
[0026] The notched shiplap edges 120, 121, 122, 128 allow each
thermal insulation panel 13 to overlap or "interlock" with adjacent
and similarly configured thermal insulation panels 13. Referring to
FIG. 5 as an example, the second short shiplap edge 121 of a first
foam board (shown as 14(a) in this Figure) can mate with the first
short shiplap edge of a second foam board (shown as 14(b) in this
Figure), and the fourth shiplap edge 123 of the first thermal
insulation panel 13(a) can mate with the third shiplap edge of a
third foam board (shown as 14(c) in this Figure).
[0027] Referring again to FIGS. 3(a) and (b), the water wicking
sheet 16 is made of a non-woven geosynthetic fabric which is
capable of drawing water away from an affected area by capillary
action is attached to and covers the top surface 124 of the foam
board 14 and extends slightly past the first short shiplap edge
120. The water repelling sheet 28 is made of a woven geosynthetic
fabric which is attached to and covers the bottom surface 126 of
the foam board 14, such as woven geosynthetic fabric 9852
manufactured by Nilex.TM.. Each of these sheets 16, 28 can be
attached by staples, or by an adhesive such as a foam adhesive such
as those manufactured by 3M.TM.. Attaching these sheets 16, 28 to
the board 14 significantly enhances the tensile and shear strength
of the panel 13.
[0028] It will be appreciated that depending on whether the source
of water originates above or below the level of the insulation
panel 13, the water repelling sheet 28 could be attached to the top
surface 124, and the non-woven wicking sheet 16 could be attached
to the bottom surface 126 instead of as illustrated.
[0029] When the thermal insulation panels 13 are interlocked, the
subsurface insulation product is formed which provides a
comprehensive thermal and moisture barrier and which is resistant
to breakage due to its robust notched shiplap edges.
[0030] Referring to FIGS. 1(b) and 2, one method of reducing ground
disturbance during freeze-thaw cycles using the second embodiment
of the subsurface insulation product includes excavating soil 10
from an affected area 12 that has been affected by ground
disturbance due to subsurface flow and subsequent freezing of
water. A plurality of the insulation panels 13 are then laid over
the affected area 12, thereby thermally insulating the affected
area 12 from freezing. Referring to FIG. 1(b), the surface of the
board 14 having the wicking sheet 16 attached thereon is laid in a
path of the subsurface flow of water. The foam board in each
insulation panel 13 is provided to reduce the likelihood of
freezing in the temperature ranges at which freeze-thaw cycles
normally occur. The wicking sheet 16 of each insulation panel 13
serves to move water away from the affected area 12, so that there
is less likelihood of ground disturbance should affected area 12
freeze.
[0031] While the above description has applied to installing the
subsurface insulation product to protect ground infrastructures in
areas having seasonal zones, the insulation product 100 can also be
useful to protect ground infrastructure used in permafrost areas,
namely to protect ground infrastructure from damage caused by
permafrost thaw.
[0032] Such ground infrastructure includes gas production equipment
on a wellsite (not shown). A method of installing the subsurface
insulation product in such a permafrost wellsite is now described.
First, the site is covered by bedding material (typically snow) to
provide a uniform surface for laying down the thermal insulation
panels 13. The side can be sloped downwards on about a 2% grade
from the wellhead (not shown) to accommodate drainage. Then, the
modular thermal insulation panels 13 are applied and interlocked
together such that the panels 13 extend slightly beyond the desired
protected zone. Then, appropriate cover such as frozen soil or
plywood is added over the subsurface insulation product. The
product will remain in place for the duration of the drilling and
for resource extraction. Once the well is shut in, the top-fill is
removed and the product can be extracted for reuse at other well
sites, leaving the present site in a remediated state.
[0033] A method of installing the subsurface insulation product in
a permafrost site having a surface pipeline is now described (but
not shown). Such an installation avoids the use of refrigeration
units on support foundations, which can drastically reduce
operation and capital costs. The support foundation is installed
by: (1) anchoring the foundation then excavating the piling area to
the permafrost level, (2) installing thermally insulated pilings,
(3) installing the subsurface insulation product by laying and
interlocking the thermal insulation panels 13 over the permafrost
soil (4) forming and pouring a concrete foundation, then (5)
backfilling the perimeter of the foundation with native material. A
pipeline corridor is installed by (1) stripping soil to the frost
line, (2) installing the subsurface insulation product by laying
and interlocking the thermal insulation panels 13, and then (3)
replacing the surface soil. Use of the insulation product under the
entire length of an elevated pipeline will allow the elevation of
the pipeline to be substantially reduced as it will insulate the
permafrost from heat radiated from the line load.
[0034] A method of installing the subsurface insulation product in
a permafrost site having subsurface pipelines is now described (but
not shown). First, a trench is excavated in conventional fashion to
a level of permafrost soil. The insulation product is installed in
the manner described above at the bottom of the trench. The
sub-surface pipeline is then laid in a conventional manner and the
trench is partially backfilled, conformed to the shape of the
sloped insulation panels. More insulation product is laid on top of
this partially backfilled material. Then the trench is completely
backfilled and the process is completed.
[0035] A method of installing the subsurface insulation product in
a permafrost site having a roadway is now described and shown in
FIG. 1(a). First, overburden is removed until permafrost 11 is
exposed. Then the insulation product is installed over the
permafrost 11 in the manner described above. Then the insulation
product 100 is covered with native soil fill 10. Finally, normal
roadway construction procedures are undertaken to complete the
roadway 18.
[0036] In this patent document, the word "comprising" is used in
its non-limiting sense to mean that items following the word are
included, but items not specifically mentioned are not excluded. A
reference to an element by the indefinite article "a" does not
exclude the possibility that more than one of the element is
present, unless the context clearly requires that there be one and
only one of the elements.
[0037] It will be apparent to one skilled in the art that
modifications may be made to the illustrated embodiment without
departing from the spirit and scope of the invention as hereinafter
defined in the Claims.
* * * * *