WO2017009839A1

WO2017009839A1 - Underground barrier system and method

Info

Publication number: WO2017009839A1
Application number: PCT/IL2016/050761
Authority: WO
Inventors: Amichai HOCHENBERG
Original assignee: Rotem Magen Ltd.
Priority date: 2015-07-16
Filing date: 2016-07-14
Publication date: 2017-01-19
Also published as: IL249571A0

Abstract

An underground barrier system comprising at least one container extending into an excavation in the ground and partitioning a first environment from a second environment. The container has fluid impermeable side walls made of a durable, pliable material and is configured for bearing at least the pressure of fluid applied therein. The container is deployed to an inflated position under pressure of said fluid bearing against the inside of the side walls.

Description

UNDERGROUND BARRIER SYSTEM AND METHOD

TECHNOLOGICAL FIELD

The present disclosure is concerned with an underground barrier system and a method for its deployment, as well as a system and method for detection of tampering such an underground barrier.

BACKGROUND ART

References considered to be relevant as background to the presently disclosed subject matter are listed below:

US 2011/250021 ;

US 5,403,125;

US 4,927,297.

Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

BACKGROUND

Though underground tunneling for military purposes is long known and dates back to biblical days, the modern terror tunnel threat is becoming a most significant danger faced by governments in many regions around the world. Over the course of years of border defense many attempts and much efforts are invested in methods, techniques and equipment for detection and destruction of underground tunnels, excavated for transporting of gods and people, and for hostile purposes.

US 2011/250021 discloses a method and arrangement for destroying tunnels. A subterraneous, vertical shaft is excavated until a tunnel preventing depth. After liquid is introduced to the shaft, a shaft liner is penetrable by the introduced liquid when a tunnel is present in the vicinity of said shaft, due to the considerably larger pressure of the introduced liquid relative to the bearing capacity of soil interposed between the tunnel and shaft. The tunnel is then flooded and destroyed following passage of the liquid through the liner. A system for detecting and destroying tunnels in the proximity of a security-sensitive facility comprises a hollow member anchored to the upper soil surface adjoining each shaft, a sensor having a unique address mounted on a corresponding hollow member for generating an electrical output when the liquid level has been reduced more than a predetermined level, and a computer in data communication with each of the sensors.

US 5,403,125 discloses an apparatus, method and system for installing water impervious barrier walls underground and particularly in levees. A mobile trailer movably mounted on rails carries upstanding front and rear masts and a carrier bar therebetween that is power driven up and down the masts. Augers mounted on the carrier bar are driven into the levee surface to create overlapping holes of loosened soil. A slurry of cement based grout is pumped through the augers to be mixed with the soil by the rotating, retracting augers to produce a soil-concrete slurry. A following mobile trailer also movably mounted on the rails is moved into position over the wall segment of uncured soil-concrete slurry. The following trailer carries a supply of water impervious membrane. Mechanism on the second trailer inserts the membrane into the soil-concrete slurry to produce a water impervious barrier wall segment. The trailers are sequentially moved along the levee to install a continuous water impervious barrier wall along the levee length.

US 4,927,297 discloses a barrier for soil structures. The barrier is formed by creating a trench in a soil structure extending from the soil surface to an impervious layer in the soil. The trench is lined with a sheet of impervious material, which may be a fabric carrying a substantially dehydrated sodium-bentonite clay. The trench is especially well- suited for installation around the perimeter of a waste site from which contaminated fluids may be emanating. The barrier and the method of forming the barrier allow a toxic waste site to be easily and completely isolated from adjacent groundwater systems.

GENERAL DESCRIPTION

According to a first aspect of the present disclosure there is disclosed an underground barrier system comprising at least one container extending into the ground and partitioning a first environment from a second environment, said container having fluid impermeable side walls made of a durable, pliable material and configured for bearing at least the pressure of fluid applied therein, and wherein said container is deployed to an inflated position under pressure of said fluid bearing against the inside of the side walls.

According to a particular configuration of the disclosure, the container of the underground barrier system is disposed within a substantially vertically extending excavation in the ground and wherein fluid pressure within the container imparts the container its inflated shape such that the container occupies a major portion of the excavation.

The container, according to a particular configuration, is sufficiently flexible such that once inflated under pressure of the occupant fluid, the container follows the wall surface of the excavation.

According to another aspect of the present disclosure there is disclosed a barrier element for use in conjunction with the underground barrier system, the barrier element comprising a container having fluid impermeable side walls made of a durable, pliable material, and configured for disposing within an excavation in the ground, said container configured for bearing at least the pressure of fluid applied therein, and wherein said container is deployed under pressure of fluid bearing against the inside of the side walls.

According to yet another aspect of the disclosure there is disclosed a method for deploying an underground barrier system, the method comprising the following steps:

a) digging an substantially vertically extending excavation in the ground; b) obtaining a container having fluid impermeable side walls made of a durable, pliable material, and configured for bearing at least the pressure of fluid applied therein;

c) introducing the container into the excavation and expanding it;

d) deploying the container into an inflated position by applying a fluid into the container.

According to a particular configuration, the method further comprises the step of introducing a grouting liquid into the excavation after step b) above;

According to one sub configuration, the curing grouting liquid (e.g. concrete, polyurethane, polyurea, rigid foam, epoxy) is introduced into the excavation during excavation, and wherein the grouting liquid is cured onto the inside wall surface of the excavation for reinforcement of the side walls.

A non-curing grouting liquid can be applied into the excavation, so as to occupy the gap between the external surface of the container and the inside walls of the excavation. As the container is being deployed into its inflated position the grouting liquid is pumped out from the excavation, so as to allow the inflated container to occupy the excavation.

Once inflated, the walls of the container apply force over the walls of the excavation, thus preventing the ground from collapsing.

The system and method of the present disclosure can further comprise various control arrangements such as different sensing arrangements for monitoring fluid pressure and pressure changes within the container, or monitoring liquid level and changes within the container.

Walls or portions of walls of the container can be configured with an array of various sensors, such as electric sensors, pressure sensors, touch sensors, cut-through sensors, acoustic sensors, etc., for detecting cutting through or puncturing of the container, and applying pressure at locations of the container walls. The sensors can be mapped such that indicia received is representative of the location of the cutting attempt or of pressure applied.

The disclosure is further concerned with a method of using an underground barrier system for the purpose of serving as a barrier and for the detection of tampering attempts with the system and attempts to penetrate the barrier. Such a method comprises a system of the aforementioned type, and wherein puncturing the container will result in leakage of the fluid occupying same, indicative of a punctured side wall of the container. The level of the fluid within the container can thus be indicative of the height of the puncture.

It is appreciated that the fluid within the container is retained under pressure of the liquid column, such that puncturing its side walls will result in powerful flow of the fluid through an opening of the container. The pressure residing within the container will result in spontaneous bursting and puncturing a side wall portion of the container, also if a side wall of the excavation is weakened, i.e. even without injuring the side wall of the container (this may occur for example upon digging at the vicinity of the pressurized container). This arrangement further ensures that the container will rupture also if tampering is performed near ground level.

Thus, the arrangement is such that fluid under pressure within the container gives rise to establishing a burst distance D whereby the wall of the container will rupture also at the event of indirect damage to the side wall of the container, e.g. as a result of weakening a portion of the side walls of the excavation. The burst distance is thus defend as the effective distance between the wall of the container and a location at the vicinity of the excavation at which soil is removed causing weakening, and resulting in rupture of the container.

According to this configuration an underground barrier can comprise two or more neighboring excavations wherein the distance L between the containers of the neighboring excavations is approximately equal to the burst distance Dl of the first container plus the burst distance D2 of the second container (L«D1+D2), wherein in case of two similar containers is L«2D.

According to a modification of the disclosure, the distance L between the two neighboring excavations is approximately equal to the burst distance Di of a first container plus the burst distance D2 of a second container plus the width W of an anticipated hostile tunnel wherein LKD1+D2+W.

In addition, if a hostile attempt is made to pass from the first environment into the second environment, e.g. by digging an underground tunnel, the immediate result will be massive flooding of the tunnel through the puncture formed in the side wall of the container.

Any one or more of the following features, design and configurations can be applied to any of the aspects of the present disclosure, separately or in various combinations:

• The container can be made of a non-toxic, environmentally friendly, material;

• Once deployed, the container can be closed and the pressure within the container can be maintained and monitored;

• The container can be open at a top end thereof, or the container can have a top wall, the container can be sealed;

• The container can be configured with one or more ports, fittings and pipes for filling and draining fluid there through;

• The container can be configured with electric coupling ports for electrically coupling communication and power wiring to sensors articulated with the container;

• The container can be anchored to the ground; anchorage can be provided at a top portion of the container and configured for anchoring to the ground near an opening of the excavation; • The barrier system can be configured with a barrier portion extending above ground level;

• The barrier system can be disguised under ground surface;

• The fluid occupying at least a portion of the container can be a gaseous material or a liquid;

• A liquid occupying the container can be fresh water, sea water, swage (treated or untreated), industrial liquid waste, fuels, bentonite, chemical agents, etc.;

• The fluid occupying the container, whether a fluid or a liquid, can comprise different additives such as coloring agents, scenting agents, different markers, chemical/biological agents such as poisonous and toxic materials, etc.;

• The container can be inflated by a tactical fluid which upon flowing into a tunnel penetrating into the container side walls can be initiated. For example, the fluid (gaseous or liquid) can be an explosive, arsons, bentonite, etc.;

• The container can be made of an inert material such that it substantially does not react with either the ground (e.g. minerals at the vicinity of the excavation) and the fluid occupying the container, thus rendering the container durable and resistant overtime;

• The container can be made of a durable material having high mechanical resistance properties such as being substantially impact resistant, tear resistant, blast resistant, and abrasive resistant. Such properties can render the container durable in case of earthquakes, animals trying to break through, etc. Such qualities offer a wide range of resistance;

• The container can be made of a durable material resistant to extreme temperatures (e.g. in the range of about -40°C to +100°C), and is also resistant to extreme temperature fluctuations;

• The container can be made of a fluid impermeable material whereby a the fluid occupying same (liquid and/or a pressurized gas) do not leak from the container;

• If punctured, the wall of the container can be amended; a punctured container can be replaced by a new one or a new one can be introduced into a punctured one; • The container is configured with a fluid impermeable, pressure resistant bottom wall;

• The bottom wall can rest over a bottom of the excavation;

• The container can extend into and through an aquifer. Thus, the bottom end of the container is theoretically unlimited and can extend as much as tens and hundreds of meters below ground level;

• A bottom portion of the container can rest within an aquifer;

• The container can assume any desired shape and dimensions. According to one example the container is polygonal (e.g. rectangle) and according to another example the container is cylindrical or elliptical;

• The container can be made of any pliable material such as PVC EPDM, rubber, polyurea, polyurethane, nylons, etc. By way of example, the container can be made from polyurethane polymers such as polyether polyurethanes, polyester polyure thanes, polyether polyureas, polyureas, polyester polyureas, polyisocyanurates and polycarbodiimides, polypropylenes, polyethylenes and high density and low density polyethylenes, ethylene propylene diene terpolymers, epoxides, polyvinyl polymers, oil-derived fractions such as bitumen and asphaltenes;

• The container can be made of, or comprise at least wall portions thereof, made of composite material, i.e. configured with at least a layer of reinforcing fibers or sheets embedded within a polymer;

• The container can be reinforced by layers and/or fibers selected amongst woven, non-woven, as well as knitted fabrics and netting fabrics, and combinations thereof. The reinforcing materails may be of a material selected from para-aramid fibers, such as Kevlar and Twaron, Cotton, Wool, Linen (flax), Sisal, Jute, Hemp, Silk, Blended fiber, cellulose, rubber, lyocell, triacetate polymers, rayon, acrylic polymers, polyesters, polyolefins, metallic fibers, glass fibers, carbon fibers; material oxides such as Alumina or aluminum-oxide, Zirconia or zirconium oxide, Fused silica and quartz; ceramic fibers; metallic fibers, plastics, fabric carrying a substantially dehydrated sodium-bentonite clay, etc.;

• Before introducing into the excavation the container can be folded or rolled or folded and rolled; • The container can be introduced into the excavation with a weight assembly articulated at a bottom end thereof and configured for dragging the container, at a non-inflated position, through the grouting liquid towards a bottom of the excavation;

• The weight can be made of any suitable material, such as metals, concrete, heavy liquids, soil, etc.;

• The container can comprise one or more filling and deploying pipes extending from a bottom portion thereof towards a top end, whereby after introducing the container into the excavation, a liquid is filled through the one or more pipes;

• The volume of fluid introduce into the container can be metered;

• The grouting liquid introduced into the excavation can be bentonite, or other liquid material such as water (fresh/sea), oils, sludge, waste liquids, polymers, etc.;

• A top end of the container can be covered or sealed to reduce or eliminate evaporation of fluid from the container;

• A top end of the container or an opening of the excavation can be protected to prevent contamination of the fluid within the container and prevent falling into the container;

• The container can be anchored to the ground, so as to prevent its displacement. According to a particular example a top portion of the container is anchored at a top portion of the excavation or above the ground. According to other examples the container is reinforced and anchored within the excavation by tendons articulated to and extending at least a portion of the container and secured to the ground;

• A ground barrier can comprise several neighboring containers; the containers can be disposed in a continuous excavation with partitions disposed between neighboring containers; neighboring excavations can be disposed in a staggering array or coextensively;

• The grouting agent can be pumped between neighboring excavations during the establishing the ground barrier;

• The container can be configured with an alert system for generating an alarm signal upon fluid level or fluid pressure changes within the container. For example the alert system can comprise a float and or a pressure sensor disposed in the container, and an alert signal can be transmitted to a control center;

• Containers of neighboring underground barriers can be in fluid communication therebetween, whereby fluid occupying said containers can be transferred between. Rupture of one container will result in enhanced fluid flow through the rupture owing to fluid flowing from the neighboring container;

• At a hostile attempt to pass from the first environment into the second environment, e.g. by digging an underground tunnel, the puncture formed in the side wall of the container allows locating the tunnel and entry into said tunnel.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

Figs. 1A to ID are schematic drawings illustrating consecutive steps of establishing an underground barrier according to an example of the present disclosure, wherein:

Fig. 1A is a vertically sectioned isometric view of introducing a container into an excavation;

Fig. IB is a top view of a deployed container within an excavation, prior to inflation thereof;

Fig. 1C is a vertical section illustrating inflating a deployed container;

Fig. ID is a vertical section illustrating an operative barrier;

Figs. 2A and 2B schematically illustrate a container rolled and folded, respectively, prior to deploying;

Figs. 3A and 3B schematically illustrate different options of folding a container;

Figs. 4A to 4F are schematic top views illustrating different configurations of an array of underground barriers;

Fig. 5 is a schematic representation of a barrier system of the disclosure, in operation;

Fig. 6 is a schematic vertically sectioned view illustrating another way of introducing a container into an excavation; Fig. 7 is a schematic illustration of an underground barrier according to yet an example of the disclosure;

Figs. 8A to 8D are schematic drawings illustrating consecutive steps of establishing an underground barrier according to another example of the present disclosure;

Fig. 9A is a schematic illustration demonstrating a burst distance of a single underground barrier;

Fig. 9B is a top elevation of Fig. 9A;

Fig. 9C is a schematic illustration demonstrating a burst distance in the case of neighboring underground barriers;

Fig. 9D is a top elevation of Fig. 9C;

Fig. 9E is a schematic illustration demonstrating another configuration of neighboring underground barriers; and

Fig. 9F is a top elevation of Fig. 9E.

DETAILED DESCRIPTION OF EMBODIMENTS

Attention is now made to the annexed drawings exemplifying several examples of a barrier according to the present disclosure.

In Fig. 1 there is illustrated an excavation 10 performed in the ground 12 below ground surface 14. The excavation 10 extends substantially vertically into the ground and has a depth H which may be as deep as desired. For example it can extend until a rock bed in the ground 12, or until an aquifer or even extend through. The excavation 10 has a width W and a thickness T. Such excavations can be performed by different machinery, setting as an example only the equipment disclosed in US Patent 5,836,089.

The excavation is performed at a location such that one of its broad walls faces an estimated direction of anticipated tunneling, thus partitioning a first environment from a second environment, namely a so-called 'hostile side' from a 'friendly side' thereof.

Once the excavation 10 is performed (or during, depending on the nature of the ground and the digging equipment) a liquid grouting agent 18 is applied into the excavation, through pipe 17 introduced into the excavation and extending from a reservoir 19, said liquid grouting agent 18 provided for preventing collapse of the excavation walls. The grouting liquid can be bentonite or other liquid material such as water (fresh/sea), oils, sludge, waste liquids, polymers, etc. Then, a barrier container 20, according to the disclosure, is introduced into the excavation. In the illustrated example (Fig. 1 A) a roll 22 of substantially endless container material, in the form of a sleeve, is supported over a spool support 24 disposed near the opening 28 of the excavation 10, in position for deploying the container 20, at a folded, non-inflated position thereof, into the excavation 10.

The container 20 is homogeneous and fluid tight, and is made of a non-toxic, environmentally friendly, material, typically an inert material such that it substantially does not react with either the ground 12 (e.g. minerals at the vicinity of the excavation) and the fluid occupying the container as will be discussed herein below, thus rendering the container durable and resistant overtime. The container 20 is be made of a durable material having high mechanical resistance properties such as being substantially impact resistant, tear resistant, abrasive resistant. Such properties can render the container durable in case of earthquakes, animals trying to break through, etc. The container is resistant to extreme temperatures (e.g. in the range of about -40°C to +100°C), and is also resistant to extreme temperature fluctuations.

According to mere examples, the container 20 can be made from polyure thane polymers such as polyether polyurethanes, polyester polyure thanes, polyether polyureas, polyureas, polyester polyureas, polyisocyanurates and polycarbodiimides, polypropylenes, polyethylenes and high density and low density polyethylenes, ethylene propylene diene terpolymers, epoxides, ruber, polyvinyl polymers, oil-derived fractions such as bitumen and asphaltenes. The container 20 can be made of, or comprise at least wall portions thereof, made of composite material, i.e. configured with at least a layer of reinforcing fibers or sheets embedded within a polymer .The container 20 can be reinforced by layers and/or fibers selected amongst woven, non-woven, as well as knitted fabrics and netting fabrics, and may be of a material selected from para-aramid fibers, such as Kevlar and Twaron, Cotton, Wool, Linen (flax), Sisal, Jute, Hemp, Silk, Blended fiber, cellulose, rubber, lyocell, triacetate polymers, rayon, acrylic polymers, polyesters, polyolefins, metallic fibers, glass fibers, carbon fibers; material oxides such as Alumina or aluminum-oxide, Zirconia or zirconium oxide, Fused silica and quartz; ceramic fibers; metallic fibers, plastics.

The container 20, before introduced into the excavation, is sealed at its leading edge 32, eventually constituting a bottom wall of the container. Furthermore, prior to deploying into the excavation 10, a plurality of weights 34 are secured to the leading edge 32. Such weights can be a concrete mass, a bag of building debris, metal, etc. With reference to Figs. 3 A and 3B it is noted that the container is deployed into the excavation at a folded, non-inflated position. The folding renders the container more compact for transportation purposes, though this is not a must. In Fig. 3A the container 20A is folded with an inwardly folded parallel end folds, and in Fig. 3B the container 20B is folded with external overlapping end folds, with a detachable connecting cord 37 configured for retaining the container at its folded position and however configured for spontaneous detaching upon inflating the container. However, it is seen that the container is fitted along its length, with one or more filing pipes 40 (two in the example as seen in Figs IB, 2A and 2B), to be discussed herein after. These filing pipes extend substantially the entire length of the container and are disposed within the container sleeve. According to another example, such pipes can be introduced into the container once deployed into the excavation.

Once fully deployed into the excavation 10 and immersed in the grouting agent 18 (Fig. IB), the leading edge 32 of the container comes to rest over a bottom surface 35 of the excavation. However, it is appreciated that the bottom edge of the container may just as well extend into an aquifer (not shown). The container sleeve is then trimmed at the top end so as to constitute a top edge of the container which in turn is anchored to the top opening 28 of the excavation 10, via ground anchors 42.

Once anchored, the container 20 is being inflated (Fig. 1C) by a fluid 50 introduced into a bottom portion of the container, through filling pipes 40. The fluid can be a liquid or gaseous material provided directly from a nearby reservoir or pumped from a tanker or container 52. A metering unit 53 is provided for measuring the amount of fluid introduced into the container.

The fluid is pumped into the container 20 inflates the container such that the side walls 54 of the container 20 bear against the inside walls of the excavation 10 and prevent their collapse. Simultaneously as the container 20 is being filled, the grouting liquid 18 is being pumped out of the excavation through pump 23 back into reservoir 19 or to a neighboring excavation, as will be discussed later, and wherein the container fluid occupies a major portion of the container 20 and applies pressure over the side walls of the excavation. The container is sufficiently flexible such that once inflated under pressure of the occupant fluid, walls of the container follow the wall surface of the excavation.

Noticeable, a liquid occupying the container 20 can be fresh water, sea water, swage (treated or untreated), industrial liquid waste, fuels, bentonite, chemical agents, etc. the fluid occupying the container, whether a fluid or a liquid, can comprise different additives such as coloring agents, scenting agents, different markers, chemical/biological agents such as poisonous and toxic materials, etc. furthermore, the container can be inflated by a tactical fluid which upon flowing into a tunnel penetrating into the container side walls can be initiated. For example, the fluid (gaseous or liquid) can be an explosive, arsons, etc.

Once deployed and inflated, the container is fitted with a cover 60 (Fig. ID) which can be camouflaged. The cover 60 prevents or reduces evaporation from the container 20 and also serves to prevent individuals and animals from falling into the container. The cover can include a door (not shown) that may be used to enter the container or the hole when the container is removed.

A fluid level alert unit 62 (or any other sensor) is applied into the container 20. According to the illustrated example the fluid level alert unit comprises a float 64 disposed within the container, with a sensing unit provided, which at the event of changes in fluid level, generates an alert signal transmitted to a control center (not shown), indicative of a puncture in the container. This can be, for example, the result of rupturing the side walls 54 during digging a tunnel through the barrier 70. The fluid level alert unit 62 can also indicate generation of waves within the container, which can be indicative of an attempt to dig a tunnel, i.e. prior to rupture of the side walls 54, or of an earthquake.

At the event of a tunnel intersecting the barrier and puncturing a wall 54 of the container 20, fluid 50 will flush the tunnel and may destroy same. An explosive liquid serving as the filling liquid 50 can be detonated, for collapsing the tunnel.

The fluid level within the container is constantly monitored by fluid level alert unit 62 and can thus provide indication as of the depth at which a tunnel is dug, for further consideration.

In Fig. 2A a container 20C is illustrated at a sleeve state, rolled over a spool supported over a dispensing support 76 In Fig. 2B a container 20D is folded in a zigzagging fashion and supported over a platform 78. Either way, the container at the sleeve state can be mobilized over trucks, trains, etc. ready for deploying at he excavation site.

In Figures 4A to 4F there are schematically illustrated deploying schemes of barrier arrays according to different examples. In Fig. 4A the barrier 80 is established by a continuous excavation 82, wherein neighboring containers 84A to 84D are disposed next to one another with a partition wall 86 disposed between each two neighboring containers. A barrier of this type is perfumed by pumping the grouting liquid from one excavation to a neighboring excavation, whilst inflating the container in said one excavation, etc. The partition walls 86 can be temporary and serve during the construction of the barrier, or they can remain permanent. Each container establishes a sub-barrier of barrier 80

In Fig. 4B the barrier 90 is established by three independent, substantially aligned, excavations 92A - 92C, each accommodating an independent container 94A - 94C, respectively, establishing sub-barriers of barrier 90.

Whilst in Figs. 4B and 4E the sub-barriers are aligned, in Figs. 4C and 4F the barriers 100 and 130, respectively, are composed of staggered sub-barriers. Fig. 4C illustrates a barrier 100 composed of staggered sub-barriers each established by an excavation 102A - 102C and a respective container therein 104A - 104C. Obviously the sub barriers can be spaced apart from one another depending on ground conditions and tactical requirements and these can also be disposed at an angle with respect to one another. The cross sections of the sub barriers can be of different sizes and shapes, for example, rectangular, oval and circular, as illustrated in Figs. 4A-4D, 4E and 4F, respectively.

Fig. 4D is yet another example of a barrier generally designated 110 and comprising sub-barriers of which three are staggered though parallel to one another, and one is inclined, comprising excavations 112A to 112D with respective containers 114A to 114D.

The above are mere examples and it is appreciated that each sub-barrier is configured for independent operation and for generating independent alarm signals, representative of their address.

Though not shown in the drawings, the container of an underground barrier according to the present disclosure can further be configured with an internal leak-proof liner, which can also increase durability, i.e. be impermeable to particular types of fluids.

In Fig. 5 there is illustrated a barrier arena comprising an underground barrier 130 similar to the disclosure herein above, however, wherein the at least the wide wall 132 of the container 134, facing an anticipated tunneling threat is further configured with an electronically detection grid 140, wherein the grid is indexed with nods Ai - Zj such that local pressure applied over the containers wall or a tampering attempt are immediately sensed and transmitted to the control center 150, so as to consider dispatching troops, etc. The electrical detection is in addition to the fluid barrier and detection system, as disclosed hereinabove.

Turning now to Fig. 6 of the drawings, there is illustrated a different method for deploying the container into an excavation. Rather than using a mass, as exemplified herein above, to cause the container (in its folded position) to sink into the excavation through the grouting slurry, in the present example there is provided a pulley system generally designated 190 used for effectively pulling the container 20' (at its folded position) and deploying it from the spool 22'.

The pulley system 190 comprises a massl94 with a pulley train 196 articulated thereto, and a cable 198 articulated at one end to a leading edge (bottom end) 200 of the container 20', and extending over a free pulley 202 towards a power pulling unit 206.

The arrangement is such that at a first step the cable 198 is attached to the bottom end 200 of the container 20', and then the mass 194 is deployed into the excavation lO'together with the pulley train 196. Once the mass 194 comes to rest over the bottom surface 35' of the excavation 10', the a power pulling unit 206 is operated so as to pull the cable 198 in direction of arrow 211, resulting in dragging of the bottom end 200 of the container into the excavation 10' until it reaches the bottom of the excavation.

Once the container is deployed, the cable 198 can be detached from the container 20' and the entire pulley system 190 can be removed from the excavation 10'.

Further attention is now made to Figures 7 to 9, directed to further examples of the disclosure. Figure 7 illustrates an underground barrier system generally designated 160 comprising a first barrier 162 and a second, neighboring barrier 164.

In the illustrated system 160 the walls of the excavation 165 are lined by a cured layer 167 of grouting type of material or the like provided for supporting the side walls of the excavation. Furthermore, a liquid grout or another substance fills the space between the container 166 and the inside walls of the excavation.

Construction of barriers 162 and 164 will be discussed hereinafter in greater detail with reference to Figs. 8A to 8E. It is seen that the underground barrier system 160 comprises a sealed container 166.

Turning now to Figs. 8A to 8E of the drawings there are illustrated consecutive steps of establishing an underground barrier according to another example of the present disclosure, wherein in Fig. 8A an excavation 198 is performed in the ground, from ground surface 200, by heavy engineering machinery, e.g. by drill 202. While excavating, a grouting liquid is poured into the excavation, e.g. bentonite poured from container 206. The bentonite supports the inside walls of the excavation and prevents their spontaneous collapsing. Once the excavation is complete, the bentonite is allowed to cure and adhered to the surface of the excavation.

Once the excavation is complete, a container 166, in collapsed form, is introduced into the excavation (Fig. 8C) with a mass 212 articulated at its leading end for pulling the collapsed container to the bottom of the excavation. Once positioned within the excavation, the container is sealed at 218 with one or more ports 222 extending from the container. The ports can be ducts for fluid flow and for pressurizing the container, as well as communication ports. Fluid, typically liquid (though as discussed herein above not restricted thereto) is then introduced into the container from a container 226 until substantially occupying the volume of the container (Fig. 8D), resulting in a liquid column under pressure.

Turning now to Figures 9A and 9B there is a representation of an under ground barrier according to the example discussed hereinbefore, wherein the pressure of the liquid within the container yields a so called burst distance D, whereby the wall of the container 166 will rupture also at the event of indirect damage to the side wall of the container, e.g. as a result of weakening a portion of the side walls of the excavation. The burst distance D is thus defined as the effective distance between the wall of the container 166 and a location at the vicinity of the excavation at which soil is removed causing weakening, and resulting in rupture of the container. Accordingly, digging an underground tunnel 225 will result in puncturing the side wall of the container 166 at distance D, i.e. even before actually reaching the container, as a result of weakening the soil at that vicinity.

Among the parameters influencing the burst distance include parameters of the container (material, thickness, etc.), type of soil at the vicinity, pressure of fluid/liquid within the container, size of the hostile tunnel, etc.

In Figs. 9C and 9D the underground barrier system 230 comprises three neighboring underground barriers 234A, 234B and 234C wherein the distance Li, L2 and L3 between each two neighboring excavations is approximately equal to the burst distance Di of one container plus the burst distance D2 of a second container (L1KD1+D2), and likewise wherein L2SSD2+D3, and L3«D3+Di. It is appreciated that in case of substantially similar containers L«2D.

In Figs. 9E and 9F the underground barrier system 250 comprises two neighboring underground barriers 254A and 254B wherein the distance L between the two neighboring excavations is approximately equal to the burst distance Di of the first container 254A plus the burst distance D2 of a second container 254B plus the width W of an anticipated hostile tunnel designated at 258, wherein LKD1+D2+W.

Claims

CLAIMS:

1. An underground barrier system comprising at least one container extending into an excavation in the ground and partitioning a first environment from a second environment, said container having fluid impermeable side walls made of a durable, pliable material and configured for bearing at least the pressure of fluid applied therein, and wherein said container is deployed to an inflated position under pressure of said fluid bearing against the inside of the side walls.

2. An underground barrier system according to claim 1, wherein the container is disposed within a substantially vertically extending excavation in the ground and wherein fluid pressure within the container imparts the container its inflated shape such that the container occupies a major portion of the excavation.

3. An underground barrier system according to claim 1, wherein the container is sealed.

4. An underground barrier system according to claim 1 , wherein parameters of the container are monitored to determine fluid level alterations within the container.

5. A barrier element for use in conjunction with an underground barrier system, the barrier element comprising a container having fluid impermeable side walls made of a durable, pliable material, and configured for disposing within an excavation in the ground, said container configured for bearing at least the pressure of fluid applied therein.

6. A method for deploying an underground barrier system, the method comprising the following steps:

a) digging an substantially vertically extending excavation in the ground; b) obtaining a container having fluid impermeable side walls made of a durable, pliable material, and configured for bearing the pressure of fluid applied therein;

c) introducing the container into the excavation and expanding it;

7. A method according to claim 6, further comprising the step of introducing a grouting liquid into the excavation during step a).

8. A method according to claim 6, further comprising the step of introducing a grouting liquid into the excavation during or after step a).

9. A method according to claim 8, wherein the grout or alike is allowed to cure and support side walls of the excavation.

10. A method according to claim 7, wherein as the container is being deployed into its inflated position the grouting liquid is pumped out from the excavation, so as to allow the inflated container to occupy the excavation.

11. A method according to claim 6, wherein the container is deployed into the excavation using a mass articulated to a bottom of the container.

12. A method according to claim 6, wherein the container is deployed into the excavation using a pulley and cable system extending at a bottom portion of the excavation, wherein the container is pulled into the excavation.

13. An underground barrier system according to claim 1, further comprising control system for monitoring fluid pressure and pressure changes within the container, and monitoring liquid level and changes within the container.

14. An underground barrier system according to claim 1 , wherein walls or portions of walls of the container are configured with an array of electric sensors for detecting cutting through the container.

15. An underground barrier system according to claim 1, wherein the container is introduced into the excavation with a weight assembly articulated at a bottom end thereof and configured for dragging the container, at a non-inflated position, through a grouting liquid towards a bottom of the excavation.

16. An underground barrier system according to claim 1, wherein the container comprises one or more pipes extending from a bottom portion thereof towards a top end, whereby after introducing the container into the excavation, a liquid is filled through the one or more pipes.