CA1166856A - Method and apparatus of constructing a novel underground impervious barrier - Google Patents
Method and apparatus of constructing a novel underground impervious barrierInfo
- Publication number
- CA1166856A CA1166856A CA000400763A CA400763A CA1166856A CA 1166856 A CA1166856 A CA 1166856A CA 000400763 A CA000400763 A CA 000400763A CA 400763 A CA400763 A CA 400763A CA 1166856 A CA1166856 A CA 1166856A
- Authority
- CA
- Canada
- Prior art keywords
- trench
- bentonite
- plastic
- sheath
- control barrier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D19/00—Keeping dry foundation sites or other areas in the ground
- E02D19/06—Restraining of underground water
- E02D19/12—Restraining of underground water by damming or interrupting the passage of underground water
- E02D19/18—Restraining of underground water by damming or interrupting the passage of underground water by making use of sealing aprons, e.g. diaphragms made from bituminous or clay material
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Hydrology & Water Resources (AREA)
- Paleontology (AREA)
- Mining & Mineral Resources (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Processing Of Solid Wastes (AREA)
- Lining And Supports For Tunnels (AREA)
- Bulkheads Adapted To Foundation Construction (AREA)
Abstract
METHOD AND APPARATUS OF CONSTRUCTING A
NOVEL UNDERGROUND IMPERVIOUS BARRIER
ABSTRACT
A novel underground impervious barrier is construc-ted by excavating a trench or slot along the desired line of the impervious barrier in the presence of a bentonite slurry. A double layered plastic film or sheet joined or folded at the bottom of the trench to form a sheath or envelope and open at the top and of sufficient verti-cal extent to extend above the ground and drape on both sides of the trench is installed in the trench and as the plastic sheath or envelope is installed in the trench it is hydraulically backfilled between the two facing surfaces thereof with a backfilling material having a greater density than the density of the bentonite slurry to sink the double layer plastic film or sheet to the bottom of the trench and displace the bentonite slurry forward in the trench toward the end being excavated.
The impervious barrier constructed is constituted by the areas of the earth on the two facing side walls of the trench which are permeated by bentonite, each side wall having a bentonite cake contiguous thereto, a plastic membrane contiguous to the outer surface of the bentonite cake and the backfill material between the facing sur-faces of the plastic membrane. Such a barrier is very useful for pollution control, for impounding water and/or otherwise effectively impeding horizontal flow of pollu-tants, water, oil and other flowable and/or substances leachable through the earth materials.
NOVEL UNDERGROUND IMPERVIOUS BARRIER
ABSTRACT
A novel underground impervious barrier is construc-ted by excavating a trench or slot along the desired line of the impervious barrier in the presence of a bentonite slurry. A double layered plastic film or sheet joined or folded at the bottom of the trench to form a sheath or envelope and open at the top and of sufficient verti-cal extent to extend above the ground and drape on both sides of the trench is installed in the trench and as the plastic sheath or envelope is installed in the trench it is hydraulically backfilled between the two facing surfaces thereof with a backfilling material having a greater density than the density of the bentonite slurry to sink the double layer plastic film or sheet to the bottom of the trench and displace the bentonite slurry forward in the trench toward the end being excavated.
The impervious barrier constructed is constituted by the areas of the earth on the two facing side walls of the trench which are permeated by bentonite, each side wall having a bentonite cake contiguous thereto, a plastic membrane contiguous to the outer surface of the bentonite cake and the backfill material between the facing sur-faces of the plastic membrane. Such a barrier is very useful for pollution control, for impounding water and/or otherwise effectively impeding horizontal flow of pollu-tants, water, oil and other flowable and/or substances leachable through the earth materials.
Description
~ :IB6%~;
This invention is dlrected to a method and apparatus for cons~ructing a novel underground impervious ~luid barrier which is useful for pollution control, lmpounding water, oil and other flowable material, especially in 5 populated areas, where government and industries are faced with the problem of arresting ~mderground seepages and situations where there is little or no gradient between the outside water table and the polluted area in-side.
Lining underground slurry trenches with impervious films such as rubber liners, plastic sheets, foils and the like has been attempted prior to this invention but they have not been particularly successful. (See page 15 130 of R.G.~. Boyersl text entitled "Structural and Cut- off Diaphragrn Walls", published by John ~laley & Sons). In Ranney U.S. Patent
This invention is dlrected to a method and apparatus for cons~ructing a novel underground impervious ~luid barrier which is useful for pollution control, lmpounding water, oil and other flowable material, especially in 5 populated areas, where government and industries are faced with the problem of arresting ~mderground seepages and situations where there is little or no gradient between the outside water table and the polluted area in-side.
Lining underground slurry trenches with impervious films such as rubber liners, plastic sheets, foils and the like has been attempted prior to this invention but they have not been particularly successful. (See page 15 130 of R.G.~. Boyersl text entitled "Structural and Cut- off Diaphragrn Walls", published by John ~laley & Sons). In Ranney U.S. Patent
2,048,710, an apparatus is disclosed for constructing an underground wall in which two rolls of lining material are carried inside wings of an excavating shield for 20 unrolling the lining material to line the walls o the trench preparatory to filling of the trench with the desired wall materi.al. There is no te~clill~ in Ranney ~r .,~ L~ .".illin~ .ntcr~ w1lictl 1~ folll~cl ~r otl~cr-wise joined) at the bottom and of sufficient height to 25 comfortably drape over the sides of the trenc~. A fea-ture of the process of the present invention is the use of the fill material to weight the lining material and dis-place the bentonite (using tne lining material to trans-mit the displacino force to the bentonite). In Zaklewicz u.S.
30 Patent 3,603,099 and Caron et al u.s. Patent 3,759r044/ a plastic sheet is immersed in a bentonic mud filled trench.
In the Zaklewicz patent the filling material is added to each side of the plastic membrane to displace the exca-~ating slurry and in the Caron et al patentl the plastic .~
I ~668,56 sheeting is immersed in a cementious bentonite filled trench and remains there until the wall material has set. Neither of these prior art references disclose the concept of applicant's double or folded plastic membrane nor is there disclosed a membrane of sufficienk vertical height to drape over the sides of the trench.
In the present invention, the double layer end fold results in a basic wall structure not disclosed in these prior art references.
The use of the lining for protecting underground pipes and conduits has been known in the art as is disclosed in Grodsk~v U.S. Patent 2,007,969 and in Keene U.S. Patent
30 Patent 3,603,099 and Caron et al u.s. Patent 3,759r044/ a plastic sheet is immersed in a bentonic mud filled trench.
In the Zaklewicz patent the filling material is added to each side of the plastic membrane to displace the exca-~ating slurry and in the Caron et al patentl the plastic .~
I ~668,56 sheeting is immersed in a cementious bentonite filled trench and remains there until the wall material has set. Neither of these prior art references disclose the concept of applicant's double or folded plastic membrane nor is there disclosed a membrane of sufficienk vertical height to drape over the sides of the trench.
In the present invention, the double layer end fold results in a basic wall structure not disclosed in these prior art references.
The use of the lining for protecting underground pipes and conduits has been known in the art as is disclosed in Grodsk~v U.S. Patent 2,007,969 and in Keene U.S. Patent
3,675,432. However, these are non-analogous to the present invention and neither of these is disclosed in the context of a slurry trench excavating process and obviously, do not in any sense teach the depth of the wall and process as disclosed herein and do not teach or suggest a membrane of 30 to ~0 feet in depth contain-ing industrial pollutants or impounding water or other flowable materials. In Grether et al U.S. Patents 3,298,183; 3,218,810 and 3,182,459, a fluid barrier is disclosed for water impoundment and/or channelization but there is no underground structure contemplated, and the double folded material is simply folded at the top above the ground and buried to anchor same against the force of the upstream water.
The basic object of the present invention is to provide an improved impervious underground wall struc-ture and an improved method and apparatus for constructing same, particularly for pollution control.
A basic feature of the invention is that the liner is a folded plastic liner (forming a sheath or envelope for the backfill material) of sufficient height so that both sides thereof can extend and drape over the sides of the slurry filled trench so that the backfill material, ~ 16B8.~;
..
which, pre~er-ral~ly, is hydraulicall~ placed and o~
; greater density than the slurry in the trench, carrles the fold line ~o the bottom of the trench and disp1aces the bentonite slurry towards the end of the excavation 5 where the excavation is taking place thereby reducing the amount of slurry needed. '~he double layer plastic is unrolled along the trench~ until e~tendi~g up above the surface is opened up and ~he backfill material is hydraulically placed between the sheets. Typ~.cally lO the backfill material may be a mixture of sand and water ;which will have two efXects. It will sink the plastic to the very bottom of the trench and make it adhere to the sides o:E the trench and will dlsplace forward the bentonite, reducing the need for a lot o bentonite for 15 excavation. The wall structure resulting rom this tech-nique is novel in that the impervious barrier that is constructed in the earth will consist o~ an area of soil adjacent the excavation which has been permeated by bentonite (e.g. the side walls of the trench), a benton-:20 ite cake, the plastic membrane, the backfill material in-side the plastic membrane (typically sand or coarse grannular material~ and the same system repeated again on the opposite trench wall side.
The advantages o the system are that it assures an 25 absolute water tightness by two identical pollutant barrier systems in series, - the soil permea~ed bentonite the bentonite cake and the plastic membrane~ Moreover, the backfill material is used to slnk the plastic sheath or envelope to the bottom of the trench, hence, once the 30 ini~ial insertion in the trench o the roll and a pre1im-inary backfilling is accomplished, the plastlc material is unrolled or unfolded from an accordion fold and floats in the trench or slot until it is opened up at the top and the backill material is inserted and the bentonite slurry is displaced to ~he opposite end of the . _. _ ._ ~_._ _ ___, _ . _ __.. __. , .. _ ._ ... ,. , . .. .... ~ . , .
I 16B8~g~
~` , . .
trencll or slot, . ; .
`~ BRIEF DESCRIPTLON OF THE DRA~.LNGS
~'. The above and other objects, advantages and eatur~
`~ of the invention will become more apparent rom ~he 5 followlng specification taken in conjunction with the .. accompanying drawings wherein: ~
:: Figure 1 is a sectional elevational view of an excavation illus~rating one embodiment of the invention, Figure 2 is a top plan view of the trench illustrated 10 in Figure 1, ~; Figure 3 is a sectional view taken on the lines 3-~
of Figure 1 illustrating the folded plastic sheet, sheath ' or envelope liner prior to being filled with a backfill material, :; 15 Figure 4 is a sectlonal view taken on lines ~-4 of ;: Figure 1 illustrating the plastic sheet, sheath or envelope ; liner after it has been filled with backfill material, Figure 5 is a sectionaI elevational view of a further ~; embodiment of the invention illustrating the plastic liner ~; 20 being fed into the trench from a rack with an accordion . folded liner, and Figure 6 is a sectional view taken on lines 6-6 of , Figure 5.
. The basic method of this invention ~or constructing 25 an under~round pol].ution control barrler cotnprlses excavat---- ing a narrow trench or slot along the desired line of the . pollution control barrier in the presence of a bentonite slurry. .It will be appreciated that while bentonite is :
. the preferred slurry, o-ther materials which perform the . 30 same function as the bentonite slurry may be used but.. ~ bentonite slurry is preferred since it can be closely . tailored to have the property of permeating the soil ! adjacent and contiguous to the excavation to form a -~} . first barrier to the polluting substance. In addition, a ,` bentonite cake forms on the wall during the e~csvsting 1 ~6~.5~
process to serve as a second barrier to the Elow of any polluting substances. After forming the initial trench excavation or slot and while the trench is full of the slurry maintaining lt open in the way disclosed in Veder U.S.
5 Patent 3,310,952, a sheath or envelope constituted by a double layered plastic membrane which is folded at the bottom of the trench and open at the top and of suffi cient vertical extent to exten~ above tlle ground surace on both sides of the trench, is inserted into the trench lO or slot. The trencn or slot T in Figure 1 has been eY~ca-vated by clam shell, backhoe, trenching apparatus and the like, to the desired depth of the barrier. Typically, this inven~ion will apply to depths of 30 to 40 feet and, in the usual case about 20 feet or down to the water 15 table level. In the i.llustrated embodimentl the trench T
is filled with a bentonite slurry B to the top of the trench slot all in accordance with the teachings of Veder U.S. Patent 3,310,952. A
portion of the loading by the lifting and placing devices ?0 10 may bP transferred to the slurry by the use of the slurry float teGhnique as disclosed in my Canadian patent application serial No. 382,745. Li~ting and placing device lO has a boom 11 carryin~ control cables 12 to a plastic fllm pay out roll 13. A frame 14 havi.ng bearings 15 and 16 for 25 roll 13 is maintained in vertical relation by stabilizing members 17 and 18 extendin~ ~rom lifting and placing device 10. The plastic film F (forming the baclcfill sheath or envelope) which, under certain circumstances can be reinforced or complemented by a woven fabric WF
30 to give it additional strength, is capable of withstand-ing the stress and avoidance of possible tears.
After the formation of the initial trench portion, - the end of the sheath or envelope constituted by the plastic film F is opened up and each of the ends is draped o~er the sides of the trench so that the fold .
~ ~6685~;
line lies in approximately the center of the trench.
In this sense, the end then will be floating on the bentonite layer and at this time, the backfill material has begun to be hydraulically placed between the sheets of plastic. Typically, a mixture of sand and water can be used which will have two effects. It will sink the plastic to the bottom of the trench or slot and make it adhere to the sides of the trench and will also displace the bentonite slurry forward in the trench by the force exited through the plastic layers thereby reducing the need for a lot of bentonite for the excavation. On the other hand, the end of the trench can be sealed and with a rigid bar member forcing the end of the envelope down to the bottom of the trench and then the envelope or sheath is filled with the backfill material as described.
Of course, the end of the sheath can be heat sealed along a vertical line joining the two sides, if desired~
By using a course granular material as a fill within the plastic, a very pervious layer enclosed in plastic can act as a filter. Draining the filter material is an excellent method of maintaining the effectiveness of the barrier and, with a minimum amount of pumping at long intervals, guaranteeing that any pollutant which crosses the initial barrier is collected and eliminated.
In Figure 3, the plastic film is shown as it is being unrolled from roll 13. As shown in the top plan view of Figure 2, the ends 20, 21 of the plastic film are draped over the surface above the side walls of the trench. The bentonite slurry B in trench T exerts a hydraulic head on the sides of the plastic film which is immersed thereby forcing any air out of the construction.
Thus, the hydraulic placement of the backfill material applies a pressure against the inside surfaces of the plastic film thereby forcing and displacing the bentonite slurry towards the excavating end of the trench thereby I 1 6 B? 8 ~ ~
recl~lcing the amount of bentonite required to perform the .
excavation.
It will be appreciated that the excavati~g slurry can in fact by a cementious bentonite mixture and the back~ill material 30 can itself be a sel:E-hardening substance such as a cement-bentoni-te mixture.
When the end of the roll 13 is approached~ -the backfilling is withheld ~or a distance of approximately 50 feet. The roll 13 i5 then lifted out of the excava-tion and the remaining portions completely unrolled and washed of bentonite material and laid flat. A second roll is then placed on the carrier and lts end unrolled and two ends are -then welded together using conventional plastic sheet welding. For example, R.F. Welding or other heat seam welding can be utilized to join the end of the new roll to the end of the old roll. The new roll is then lowered back into the trench or slot T
and the backfilling operation resumes along with the excavating of the forward end oE the trench.
: 20 In this regard, instead of the -roll being ver~ical and instead of a fold at the bottom of the trench, the roll is not folded but is simply rolled along the top of the trench so that it floats on the bentonite slurry.
The ends o~ the roll extend qu~te some ~ls~ance L?eyond the edges of the excavation and the end o the roll is then pushed to tlle bo~tom O;r t~e trench ~ither by the back~ill material or by a rigid rod and the backfilllng operation commenced. In this case, the roll per se never goes below the surface but -the ends thereof is open and clear for performing the welding operation to add -the next roll on.
Larger rolls can be accomodated by varying the thickness of the trench along the line of the barrier.
Thus, as the~roll is payed out ? the trench can be made narrower, this approach having the advantage of permitting longer -rolls and minimizing the number of join~s.
.
~ 6 Referring now to Figure S, a backhoe excavator 40 is shown excavating the trench or slot T' which is maintained full of bentonite slurry B, A rack 41 with a accordion folded liner F' is coupled by pulling 5 cables or a draw bar to backhoe 40. In this method, the laying of the plastic comprises in folding it up accor-dion style in a large roll above ground with the back-fill material opening up the folds and pushing the plas-tic down into the trench as illus trated in Fig~re S. The lO joining of the ends of the film F' of a new roll to the ~ old roll does not thereby require the removing o~ the ; expended roll as in the embodiment of Figure 1. As shown in Figure 6, there is as in the case of Figure 4, a bentonite jell of a zone of bentonite intrusion 5, a 15 bentonite cake 6 and plastic layer or sheet 7 on each side of the trench and the backfill material of'sand, ' gravel etc. It will be appreciated that the plastic ; film can be payed out from a pair of parallel rolls and prior to entry to the trench heat sealed or other-20 wise bonded at the lower edges o;E the two rolls to form t the joint that will eventually be at the bottom of ~he trench.
Thus, there has be~n disclosed an improved process an~ apparatus ~or con.s~ructlng a novel ~mpe~me.~ble mem-25 ~rLInc o~ 30 ~o ~0 eet in dcpth which i3 pnrticularl~
useful or containing areas of industrial pollutants and arresting underground seepage where there is little or i no gradient between the outside water table and the polluted area inside. Moreover, the invention has 30 applicability to forming water and petroleum impound-ments, cut-off walls and water channelization at rela-tively high rate of installation and at relatively low ; cost.
~! ' ~; While I have disclosed severaI embodiments of the invention and sugg~sted other modifications, it will be apparent that many modifications which will be obvious 3~e~ 6 to those skilled in the art and i~ is inten(led ~hat such modifications be encompassecl within the spirit and scope oE the claims appended hereto.
. ; ' -. ..
The basic object of the present invention is to provide an improved impervious underground wall struc-ture and an improved method and apparatus for constructing same, particularly for pollution control.
A basic feature of the invention is that the liner is a folded plastic liner (forming a sheath or envelope for the backfill material) of sufficient height so that both sides thereof can extend and drape over the sides of the slurry filled trench so that the backfill material, ~ 16B8.~;
..
which, pre~er-ral~ly, is hydraulicall~ placed and o~
; greater density than the slurry in the trench, carrles the fold line ~o the bottom of the trench and disp1aces the bentonite slurry towards the end of the excavation 5 where the excavation is taking place thereby reducing the amount of slurry needed. '~he double layer plastic is unrolled along the trench~ until e~tendi~g up above the surface is opened up and ~he backfill material is hydraulically placed between the sheets. Typ~.cally lO the backfill material may be a mixture of sand and water ;which will have two efXects. It will sink the plastic to the very bottom of the trench and make it adhere to the sides o:E the trench and will dlsplace forward the bentonite, reducing the need for a lot o bentonite for 15 excavation. The wall structure resulting rom this tech-nique is novel in that the impervious barrier that is constructed in the earth will consist o~ an area of soil adjacent the excavation which has been permeated by bentonite (e.g. the side walls of the trench), a benton-:20 ite cake, the plastic membrane, the backfill material in-side the plastic membrane (typically sand or coarse grannular material~ and the same system repeated again on the opposite trench wall side.
The advantages o the system are that it assures an 25 absolute water tightness by two identical pollutant barrier systems in series, - the soil permea~ed bentonite the bentonite cake and the plastic membrane~ Moreover, the backfill material is used to slnk the plastic sheath or envelope to the bottom of the trench, hence, once the 30 ini~ial insertion in the trench o the roll and a pre1im-inary backfilling is accomplished, the plastlc material is unrolled or unfolded from an accordion fold and floats in the trench or slot until it is opened up at the top and the backill material is inserted and the bentonite slurry is displaced to ~he opposite end of the . _. _ ._ ~_._ _ ___, _ . _ __.. __. , .. _ ._ ... ,. , . .. .... ~ . , .
I 16B8~g~
~` , . .
trencll or slot, . ; .
`~ BRIEF DESCRIPTLON OF THE DRA~.LNGS
~'. The above and other objects, advantages and eatur~
`~ of the invention will become more apparent rom ~he 5 followlng specification taken in conjunction with the .. accompanying drawings wherein: ~
:: Figure 1 is a sectional elevational view of an excavation illus~rating one embodiment of the invention, Figure 2 is a top plan view of the trench illustrated 10 in Figure 1, ~; Figure 3 is a sectional view taken on the lines 3-~
of Figure 1 illustrating the folded plastic sheet, sheath ' or envelope liner prior to being filled with a backfill material, :; 15 Figure 4 is a sectlonal view taken on lines ~-4 of ;: Figure 1 illustrating the plastic sheet, sheath or envelope ; liner after it has been filled with backfill material, Figure 5 is a sectionaI elevational view of a further ~; embodiment of the invention illustrating the plastic liner ~; 20 being fed into the trench from a rack with an accordion . folded liner, and Figure 6 is a sectional view taken on lines 6-6 of , Figure 5.
. The basic method of this invention ~or constructing 25 an under~round pol].ution control barrler cotnprlses excavat---- ing a narrow trench or slot along the desired line of the . pollution control barrier in the presence of a bentonite slurry. .It will be appreciated that while bentonite is :
. the preferred slurry, o-ther materials which perform the . 30 same function as the bentonite slurry may be used but.. ~ bentonite slurry is preferred since it can be closely . tailored to have the property of permeating the soil ! adjacent and contiguous to the excavation to form a -~} . first barrier to the polluting substance. In addition, a ,` bentonite cake forms on the wall during the e~csvsting 1 ~6~.5~
process to serve as a second barrier to the Elow of any polluting substances. After forming the initial trench excavation or slot and while the trench is full of the slurry maintaining lt open in the way disclosed in Veder U.S.
5 Patent 3,310,952, a sheath or envelope constituted by a double layered plastic membrane which is folded at the bottom of the trench and open at the top and of suffi cient vertical extent to exten~ above tlle ground surace on both sides of the trench, is inserted into the trench lO or slot. The trencn or slot T in Figure 1 has been eY~ca-vated by clam shell, backhoe, trenching apparatus and the like, to the desired depth of the barrier. Typically, this inven~ion will apply to depths of 30 to 40 feet and, in the usual case about 20 feet or down to the water 15 table level. In the i.llustrated embodimentl the trench T
is filled with a bentonite slurry B to the top of the trench slot all in accordance with the teachings of Veder U.S. Patent 3,310,952. A
portion of the loading by the lifting and placing devices ?0 10 may bP transferred to the slurry by the use of the slurry float teGhnique as disclosed in my Canadian patent application serial No. 382,745. Li~ting and placing device lO has a boom 11 carryin~ control cables 12 to a plastic fllm pay out roll 13. A frame 14 havi.ng bearings 15 and 16 for 25 roll 13 is maintained in vertical relation by stabilizing members 17 and 18 extendin~ ~rom lifting and placing device 10. The plastic film F (forming the baclcfill sheath or envelope) which, under certain circumstances can be reinforced or complemented by a woven fabric WF
30 to give it additional strength, is capable of withstand-ing the stress and avoidance of possible tears.
After the formation of the initial trench portion, - the end of the sheath or envelope constituted by the plastic film F is opened up and each of the ends is draped o~er the sides of the trench so that the fold .
~ ~6685~;
line lies in approximately the center of the trench.
In this sense, the end then will be floating on the bentonite layer and at this time, the backfill material has begun to be hydraulically placed between the sheets of plastic. Typically, a mixture of sand and water can be used which will have two effects. It will sink the plastic to the bottom of the trench or slot and make it adhere to the sides of the trench and will also displace the bentonite slurry forward in the trench by the force exited through the plastic layers thereby reducing the need for a lot of bentonite for the excavation. On the other hand, the end of the trench can be sealed and with a rigid bar member forcing the end of the envelope down to the bottom of the trench and then the envelope or sheath is filled with the backfill material as described.
Of course, the end of the sheath can be heat sealed along a vertical line joining the two sides, if desired~
By using a course granular material as a fill within the plastic, a very pervious layer enclosed in plastic can act as a filter. Draining the filter material is an excellent method of maintaining the effectiveness of the barrier and, with a minimum amount of pumping at long intervals, guaranteeing that any pollutant which crosses the initial barrier is collected and eliminated.
In Figure 3, the plastic film is shown as it is being unrolled from roll 13. As shown in the top plan view of Figure 2, the ends 20, 21 of the plastic film are draped over the surface above the side walls of the trench. The bentonite slurry B in trench T exerts a hydraulic head on the sides of the plastic film which is immersed thereby forcing any air out of the construction.
Thus, the hydraulic placement of the backfill material applies a pressure against the inside surfaces of the plastic film thereby forcing and displacing the bentonite slurry towards the excavating end of the trench thereby I 1 6 B? 8 ~ ~
recl~lcing the amount of bentonite required to perform the .
excavation.
It will be appreciated that the excavati~g slurry can in fact by a cementious bentonite mixture and the back~ill material 30 can itself be a sel:E-hardening substance such as a cement-bentoni-te mixture.
When the end of the roll 13 is approached~ -the backfilling is withheld ~or a distance of approximately 50 feet. The roll 13 i5 then lifted out of the excava-tion and the remaining portions completely unrolled and washed of bentonite material and laid flat. A second roll is then placed on the carrier and lts end unrolled and two ends are -then welded together using conventional plastic sheet welding. For example, R.F. Welding or other heat seam welding can be utilized to join the end of the new roll to the end of the old roll. The new roll is then lowered back into the trench or slot T
and the backfilling operation resumes along with the excavating of the forward end oE the trench.
: 20 In this regard, instead of the -roll being ver~ical and instead of a fold at the bottom of the trench, the roll is not folded but is simply rolled along the top of the trench so that it floats on the bentonite slurry.
The ends o~ the roll extend qu~te some ~ls~ance L?eyond the edges of the excavation and the end o the roll is then pushed to tlle bo~tom O;r t~e trench ~ither by the back~ill material or by a rigid rod and the backfilllng operation commenced. In this case, the roll per se never goes below the surface but -the ends thereof is open and clear for performing the welding operation to add -the next roll on.
Larger rolls can be accomodated by varying the thickness of the trench along the line of the barrier.
Thus, as the~roll is payed out ? the trench can be made narrower, this approach having the advantage of permitting longer -rolls and minimizing the number of join~s.
.
~ 6 Referring now to Figure S, a backhoe excavator 40 is shown excavating the trench or slot T' which is maintained full of bentonite slurry B, A rack 41 with a accordion folded liner F' is coupled by pulling 5 cables or a draw bar to backhoe 40. In this method, the laying of the plastic comprises in folding it up accor-dion style in a large roll above ground with the back-fill material opening up the folds and pushing the plas-tic down into the trench as illus trated in Fig~re S. The lO joining of the ends of the film F' of a new roll to the ~ old roll does not thereby require the removing o~ the ; expended roll as in the embodiment of Figure 1. As shown in Figure 6, there is as in the case of Figure 4, a bentonite jell of a zone of bentonite intrusion 5, a 15 bentonite cake 6 and plastic layer or sheet 7 on each side of the trench and the backfill material of'sand, ' gravel etc. It will be appreciated that the plastic ; film can be payed out from a pair of parallel rolls and prior to entry to the trench heat sealed or other-20 wise bonded at the lower edges o;E the two rolls to form t the joint that will eventually be at the bottom of ~he trench.
Thus, there has be~n disclosed an improved process an~ apparatus ~or con.s~ructlng a novel ~mpe~me.~ble mem-25 ~rLInc o~ 30 ~o ~0 eet in dcpth which i3 pnrticularl~
useful or containing areas of industrial pollutants and arresting underground seepage where there is little or i no gradient between the outside water table and the polluted area inside. Moreover, the invention has 30 applicability to forming water and petroleum impound-ments, cut-off walls and water channelization at rela-tively high rate of installation and at relatively low ; cost.
~! ' ~; While I have disclosed severaI embodiments of the invention and sugg~sted other modifications, it will be apparent that many modifications which will be obvious 3~e~ 6 to those skilled in the art and i~ is inten(led ~hat such modifications be encompassecl within the spirit and scope oE the claims appended hereto.
. ; ' -. ..
Claims (14)
1. An underground fluid material flow control barrier: comprising 1) a narrow slot in the earth having a length extending across the expected pollution path and a depth extending at least to the water table, 2) bentonite impregnating the earth walls of said slot and forming a bentonite cake on the inner surfaces thereof, 3) a plastic sheath in said narrow slot and in contiguous relation to all surfaces in said slot and, 4) a material filling said sheath having a density greater than bentonite slurry used in forming said narrow slot.
2. The underground fluid material flow control barrier defined in Claim 1 including means in said sheath for draining the backfill material.
3. The underground fluid material flow control barrier defined in Claim 1 wherein said material filling said sheath is sand.
4. The underground fluid material flow control barrier defined in Claim 1 wherein said material filling said sheath is a self-hardenable wall forming material.
5. The underground fluid material flow control barrier defined in Claim 1 wherein said material filling said sheath is a mixture of cement and bentonite.
6. The underground fluid material flow control barrier defined in Claim 1 wherein said plastic sheath includes a strengthening material.
7. The underground fluid material flow control barrier defined in Claim 6 wherein said strengthening material is a woven fabric.
8. The underground fluid control barrier defined in Claim 1 wherein soil material filling said sheath is a coarse granular material, and means for draining said coarse granular material.
9. A pollution control barrier comprising a narrow slot in the earth, said slot extending downwardly in the earth at least to the water table, a plastic sheath contacting at least the sides and bottom of said slot, and a backfill material contained within said plas-tic sheath.
10. A method of constructing an underground fluid barrier comprising:
excavating a trench along the desired line of said barrier in the presence of a bentonite slurry, said trench having a pair of facing side walls, and simultaneously installing a flexible imper-vious lining material adjacent each of said facing walls and along the bottom of said trench and backfilling the space between said lining material and displacing said bentonite slurry in a selected direction by said lining material.
excavating a trench along the desired line of said barrier in the presence of a bentonite slurry, said trench having a pair of facing side walls, and simultaneously installing a flexible imper-vious lining material adjacent each of said facing walls and along the bottom of said trench and backfilling the space between said lining material and displacing said bentonite slurry in a selected direction by said lining material.
11. The method defined in Claim 10 wherein said lining material is plastic.
12. The method defined in Claim 10 wherein said backfilling material is a coarse granular material which in bulk, is surrounded on at least the bottom and sides thereof by said lining material and as installed dis-places said bentonite slurry in said direction,
13. The method defined in Claim 10 wherein said flexible impervious lining material is constituted by a pair of plastic sheets which have been hermetically joined at their contiguous lower edges to form an impervious envelope in said trench.
14. A method of constructing an underground pollu-tion control barrier comprising:
excavating a trench along the desired line of said pollution control barrier in the presence of a excavation slurry, installing a double layered plastic membrane which is joined at the bottom of the trench and opened at the top and of sufficient vertical extent to extend above the ground surface on both sides of said trench, as said double layer plastic membrane is in-stalled in the trench, hydraulically backfilling between the two facing surfaces of said double layered plastic membrane with a backfilling material, said backfilling material having a density greater than the density of the bentonite slurry to sink the membrane to the bottom of said trench and displace the bentonite slurry forward in the trench toward the end being excavated and reduce the amount of bentonite needed for the excavation, whereby said pollution control barrier is con-stituted by the areas of the two earth side walls of the trench each side wall being permeated by bentonite and having bentonite cake contiguous thereto, a plastic mem-brane and the backfill material between the facing sur-faces of said plastic membrane.
excavating a trench along the desired line of said pollution control barrier in the presence of a excavation slurry, installing a double layered plastic membrane which is joined at the bottom of the trench and opened at the top and of sufficient vertical extent to extend above the ground surface on both sides of said trench, as said double layer plastic membrane is in-stalled in the trench, hydraulically backfilling between the two facing surfaces of said double layered plastic membrane with a backfilling material, said backfilling material having a density greater than the density of the bentonite slurry to sink the membrane to the bottom of said trench and displace the bentonite slurry forward in the trench toward the end being excavated and reduce the amount of bentonite needed for the excavation, whereby said pollution control barrier is con-stituted by the areas of the two earth side walls of the trench each side wall being permeated by bentonite and having bentonite cake contiguous thereto, a plastic mem-brane and the backfill material between the facing sur-faces of said plastic membrane.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US25267681A | 1981-04-09 | 1981-04-09 | |
| US252,676 | 1981-04-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1166856A true CA1166856A (en) | 1984-05-08 |
Family
ID=22957033
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000400763A Expired CA1166856A (en) | 1981-04-09 | 1982-04-08 | Method and apparatus of constructing a novel underground impervious barrier |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0062808A1 (en) |
| JP (1) | JPS5813820A (en) |
| CA (1) | CA1166856A (en) |
| DE (1) | DE62808T1 (en) |
| ES (2) | ES511346A0 (en) |
| PT (1) | PT74719B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108203990A (en) * | 2017-12-19 | 2018-06-26 | 苏州大学 | The construction method of compound underground anti-seepage swelling cob wall |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL8700147A (en) * | 1987-01-21 | 1988-08-16 | Digging Trading | METHOD FOR GROUNDING A SCREEN OF FLEXIBLE MATERIAL |
| CN110042855B (en) * | 2019-04-25 | 2020-12-25 | 倡创(上海)咨询管理事务所 | Concrete impervious wall and construction method |
| CN113062296A (en) * | 2021-04-02 | 2021-07-02 | 交通运输部天津水运工程科学研究所 | Vacuum preloading boundary sealing method |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1634517A1 (en) * | 1966-06-21 | 1970-08-06 | Polensky & Zoellner | Method of making underground sealing walls |
| DE1915688A1 (en) * | 1968-06-26 | 1970-03-12 | Mansfeld Kombinat W Pieck Veb | Waterproof sheet laying appliance for use in trenches - in the ground |
| FR2038719A5 (en) * | 1969-03-27 | 1971-01-08 | Sif Entreprise Bachy | |
| FR2094290A5 (en) * | 1970-06-16 | 1972-02-04 | Soletanche | |
| DE2252599A1 (en) * | 1971-10-29 | 1973-05-03 | Hofman & Maculan Bauaktiengese | PROCESS FOR PRODUCING UNDERGROUND WALLS FROM CASTABLE, CURING MATERIAL, IN PARTICULAR CONCRETE, AND FORMWORK FOR CARRYING OUT THIS PROCESS |
| DE2546946A1 (en) * | 1975-10-20 | 1977-04-28 | Eurosond Gmbh Spezialunternehm | Buried sealing wall production - has workable plastic erosion resistant sealing mass and sealing membrane |
-
1982
- 1982-03-26 DE DE1982102538 patent/DE62808T1/en active Pending
- 1982-03-26 EP EP82102538A patent/EP0062808A1/en not_active Ceased
- 1982-04-07 PT PT7471982A patent/PT74719B/en unknown
- 1982-04-08 ES ES511346A patent/ES511346A0/en active Granted
- 1982-04-08 CA CA000400763A patent/CA1166856A/en not_active Expired
- 1982-04-09 JP JP5949282A patent/JPS5813820A/en active Pending
-
1983
- 1983-04-15 ES ES521511A patent/ES8406099A1/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108203990A (en) * | 2017-12-19 | 2018-06-26 | 苏州大学 | The construction method of compound underground anti-seepage swelling cob wall |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5813820A (en) | 1983-01-26 |
| ES8402381A1 (en) | 1984-02-01 |
| PT74719A (en) | 1982-05-01 |
| PT74719B (en) | 1983-10-25 |
| ES511346A0 (en) | 1984-02-01 |
| ES521511A0 (en) | 1984-07-16 |
| DE62808T1 (en) | 1983-06-23 |
| ES8406099A1 (en) | 1984-07-16 |
| EP0062808A1 (en) | 1982-10-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4877358A (en) | Method and apparatus of constructing a novel underground impervious barrier | |
| EP0135584B1 (en) | Environmental cut-off for deep excavations | |
| US4741644A (en) | Environmental cut-off and drain | |
| US5106233A (en) | Hazardous waste containment system | |
| US5240348A (en) | Methods of hazardous waste containment | |
| US5118230A (en) | Method and apparatus for installation of leachate containment system | |
| US4543016A (en) | Underground leachate barrier and method of making same | |
| US3736754A (en) | Reservoirs for the storage of liquids especially volatile liquids | |
| US5259705A (en) | Guide box assembly system for in-ground barrier installation | |
| US5685668A (en) | Barrier wall installation system | |
| US11560686B2 (en) | Membrane-lined wall | |
| JPS6122698B2 (en) | ||
| US10538889B2 (en) | Berm or levee expansion system and method | |
| CA2060007A1 (en) | Hazardous waste containment system | |
| CA1166856A (en) | Method and apparatus of constructing a novel underground impervious barrier | |
| GB2136861A (en) | Process for the construction of insulated sites in particular for the discharge of polluant products or the formation of impervious barricades or barriers, and works thereby constructed | |
| JP4979228B2 (en) | Additional construction method of impermeable layer | |
| JP2004204581A (en) | Water sealing method for controlled revetment | |
| US5246312A (en) | System and method for producing a composite cutoff wall | |
| US3968658A (en) | Method and apparatus for introducing water-proof sheeting into the ground in a vertical position | |
| RU2272869C2 (en) | Storage pit building method | |
| JP2001323432A (en) | Impervious structure of revetment | |
| KR101404471B1 (en) | Embankment constuction by buoyancy and water pressure on the part prevention of injury and in the force functioning bottom, a mat and execution method for filter | |
| JP2900129B2 (en) | Method of constructing continuous underground wall and continuous underground wall | |
| JP4104467B2 (en) | Seawall structure and seawall construction method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |