WO2023170388A1

WO2023170388A1 - Method and system of building an underground structure

Info

Publication number: WO2023170388A1
Application number: PCT/GB2023/050506
Authority: WO
Inventors: Steve Jordan; Alan Meeks
Original assignee: Hypertunnel Ip Limited
Priority date: 2022-03-08
Filing date: 2023-03-03
Publication date: 2023-09-14
Also published as: GB202203197D0; GB2613209A

Abstract

Jet grouting involves injecting grout into geological material to improve its quality; however, use of jet grouting is limited to situations in which the injection systems can be positioned relatively close to the region to be improved. However, such jet grouting systems lack the precision to form complex and stable structures. The present invention enables underground structures to be built before excavation is carried out by casting blocks in-situ. In particular, structural blocks may be formed from grouting compound and/or cement in the shape of a tunnel to be excavated, and/or around an underground asset (such as deteriorating nuclear waste containers).

Description

METHOD AND SYSTEM OF BUILDING AN UNDERGROUND STRUCTURE

The present invention relates generally to a method and system of building an underground structure and finds particular, although not exclusive, utility in tunnel construction.

Pressure grouting and jet grouting are known techniques in which grout is injected into geological material (for example soil, sand and/or rock) to improve its quality, for instance to correct faults, improve its strength and/or reduce water flow through it. Such grouting techniques are often used around the foundations of large structures (buildings, bridges, etc.) and around underground structures including large pipes and tunnels. Typically, in pressure grouting, grout is injected into geological material to fill any interconnected pores and voids, in order to stabilise it without disturbing the existing material. In contrast, jet grouting is typically achieved with a relatively high velocity jet of grout, which is used to erode and significantly mix up geological materials in-situ, and often to form specific shapes (e.g. columns and/or platforms).

However, such jet grouting systems lack the precision to form complex and stable structures.

According to a first aspect of the present invention, there is provided a method of building an underground structure, the method comprising the steps of: drilling an underground bore through underlying geology; lining the bore with a pipe; passing cutting equipment down the pipe to a predetermined location; cutting a three-dimensional volume outside the pipe using the cutting equipment; passing deployment equipment down the pipe to the predetermined location; and deploying material into the three-dimensional volume using the deployment equipment.

In this way, underground structures may be built before excavation is carried out. In particular, structural blocks may be formed from grouting compound and/or cement (including concrete/composite materials, for instance incorporating aggregate such as sand, gravel, crushed stone, slag, or recycled crushed concrete) in the shape of a tunnel to be excavated, and/or around an underground asset (such as deteriorating nuclear waste containers). That is, building blocks may be cast in-situ by forming moulds from the underlying geology.

The cutting equipment may comprise an articulated and/or flexible arm that can be manoeuvred through a hole in the pipe and controlled to drill out the desired three-dimensional volume. The cutting equipment may comprise a cutting head on one end of the arm, the cutting head may be interchangeable with cutting heads having different coarseness. For example, a coarse cutting head may be used to form a large open space within the three-dimensional volume quickly; a fine cutting head may be used to shape the large open space to a desired shape; that is, conforming to the desired three-dimensional volume. Cutting the three-dimensional volume outside the pipe may comprise performing a coarse cut with coarse cutting equipment, followed by performing a fine cut with fine cutting equipment.

The cutting may involve using fluid such as water, drilling mud and/or slurry (e.g. a mixture of water and clay) in the three-dimensional volume. For example, a pressure of the mud and/or slurry may prevent the surrounding material from collapsing into the cut volume. In addition, if the fluid is pumped into the volume at sufficiently high velocity, broken rock fragments may be carried out by the fluid current.

The method may further comprise: moving the cutting equipment to a second predetermined location within the pipe; cutting a second three-dimensional volume outside the pipe, adjacent to the first three-dimensional volume, using the cutting equipment; moving the deployment equipment to the second predetermined location; and deploying material into the second three-dimensional volume using the deployment equipment.

Alternatively or additionally, the method may further comprise: providing second cutting equipment in the or a second pipe at a second predetermined location; cutting a second three-dimensional volume outside the pipe, adjacent to the first three-dimensional volume, using the second cutting equipment; providing second deployment equipment (or moving the first deployment equipment) to the second predetermined location; and deploying material into the second three-dimensional volume using the first/second deployment equipment.

In this way, a structure may be built of adjacent blocks, for instance making the structure water-tight. In some arrangements, the or each block may be surrounded with a sealant, such that adjacent blocks are joined by a gasket to prevent liquid seepage therebetween. For example, the sealant may be introduced into the first and/or second three-dimensional volume, coating the interior of the volume, before material is deployed therein.

The first three-dimensional volume and the second three-dimensional volume may be configured to interlock with one another. That is, one or each of the volumes may have a concave portion into which the other volume is arranged to project, forming an interlocking stabilised structure, such that sufficient stability is achieved for subsequent operations.

Optionally, the first block may be left to set/cure prior to cutting the second three-dimensional volume. In this way, material may not leak from one or the first block into an adjacent block.

Underground may mean any sub-terranean location. The surrounding geology may mean geological material adjacent to the predetermined location, and may be within the underlying geology.

Deployment may comprise deployment of material. Deployment may comprise injection/introduction (e.g. of material).

Materials may comprise grout and/or remedial substances, such as epoxy resin, polyurethane foam, polyurethane resins, acrylic resins, cementitious grouts and aqueous solutions. The treatment material may comprise concrete/composite materials, for instance incorporating aggregate such as sand, gravel, crushed stone, slag, or recycled crushed concrete. The grout may be a cementitious, resinous, or solution chemical mixture.

Each block produced by the present method may be the same as each other block, or may be tailored to its specific environment and/or end use. For example, a mix of grout may be selected for some blocks to favour compressive strength, water permeability, resistance to corrosion, appearance etc.

The or each block may be provided with structural reinforcement, for example by introducing rebars and/or metal coils into the volume prior to deployment of material therein. Alternatively or additionally to introducing structural reinforcement into the volume, sensor devices (such as ground penetrating radar transceivers, connecting wires, seismic equipment, etc.) may be introduced into the volume prior to deployment of material therein. In particular, the structural reinforcement and/or sensor devices may be deployed from the pipe, in in particular from a carriage therein.

Prior to cutting the three-dimensional volume, the method may further comprise: passing treatment equipment down the pipe to the predetermined location; and deploying treatment material into the underlying geology.

The treatment material may comprise grout and/or remedial substances, such as epoxy resin, polyurethane foam, polyurethane resins, acrylic resins, cementitious grouts and aqueous solutions. The treatment material may comprise concrete/composite materials, for instance incorporating aggregate such as sand, gravel, crushed stone, slag, or recycled crushed concrete. The grout may be a cementitious, resinous, or solution chemical mixture.

Treating, may comprise stabilising the underlying geology. In this way, in cases where the material outside the region is relatively weak, contains voids, is unstable, or waterlogged, the material can be stabilised. Equipment may be placed down-bore to stabilise the underlying geology outside the pipe.

Stabilisation may be via ground freezing techniques, for instance by coolant pumped through the hole in the pipe. Freezing techniques may be temporary. Permanent stabilisation may be achieved by deploying chemical stabiliser, for instance via chemical delivery nozzles (e.g. within telescopic arms). The amount and type of stabiliser used will be determined by the geology to be stabilised and can be controlled as required, and may comprise cement or any other suitable material such as microcements, mineral grouts (known as colloidal silica), water sensitive polyurethanes (rapid reacting foaming resin to combat water ingress), quick reacting and non-water sensitive polyurea silicate systems (expanding foam for void filling), acrylic resins, jet grouting viz. the in situ construction of solidified ground to a designed characteristic; often known as Soilcrete (RTM), concrete/composite materials, for instance incorporating aggregate such as sand, gravel, crushed stone, slag, or recycled crushed concrete, etc.

Stabilisation of the underlying geology may greatly reduce, if not completely prevent, further water ingress.

Drilling an underground bore through underlying geology may comprise using a Directional Boring technique as used in the mining, oil and gas, and construction industries. For example, Horizontal Directional Drilling (HDD) is used for installing pipes, etc. HDD is capable of boring suitably accurate bores up to ~800m long with diameters only between 100mm and 1200mm. Alternatively, directional drilling is used in the oil & gas industry, and enables much longer bores to be bored.

The method may comprise excavating underlying geology from around the three-dimensional volumes once they have hardened into blocks.

The pipe may comprise a liner for lining the bore. In this way, the integrity of the bore may be protected. Lining may comprise lining the whole bore, or only a portion of the bore. The liner may comprise a solid wall.

The hole may comprise a single hole or a plurality of holes. The hole(s) may comprise any form of opening, such as a circular through-hole, a slot, etc.

Prior to cutting the three-dimensional volume, the method may further comprise the steps of: passing perforation equipment (e.g. drilling equipment, or some other form of equipment for making a hole) down the bore to the predetermined location along the predetermined path; and/or using the perforation equipment to make a hole(s) at least partially through the pipe at the predetermined location(s). The hole(s) may be made by drilling, piercing, milling, punching, gouging, cutting, and/or any other suitable method.

In this way, a way for the material to be deployed through the pipe is enabled.

The perforation equipment may comprise a carriage upon which is mounted a drill or some other form of device for making the hole(s). The drill/device may be retractable (e.g. telescopically, longitudinally and/or pivotally). The device may for example comprise a milling head that indexes around that may be configured to create a single or a variety of shapes of opening in the pipe.

The method may further comprise the step of: using the equipment to make the hole at most only partially through the pipe at the predetermined location.

In this way, external material and/or water may be prevented from entering the bore in an uncontrolled manner. In particular, the holes may extend almost all the way through the pipe wall (e.g. to less than 2mm, in particular less than 1mm from the outer surface of the pipe wall).

In alternative arrangements, the drill/device may be configured to make the hole entirely through the pipe, and may even be configured to drill, etc. into the surrounding geology.

The pipe may include the holes prior to insertion into the bore.

For example, the pipe may be pre-perforated. In this way, time and cost on site may be avoided in situations in which the underlying geology is well understood. The pre-perforated liner may comprise an outer sleeve that covers the perforations; in this way, external material and/or water may be prevented from entering the bore in an uncontrolled manner. The outer sleeve may be relatively easy to push or cut through, thereby allowing desired access outside the pipe, while preventing accidental ingress into the pipe.

For example, the various equipment may be configured to punch through the pipe wall; in particular, configured to punch through either the small amount of pipe wall remaining after drilling etc., or the sleeve of a pre-perforated pipe.

The pipe and/or liner may comprise a plastics material, as is well understood in the art.

Various equipment (including the drilling equipment and/or the deployment equipment) may be passed through the pipe in a conventional manner to perform operations at any desired location. For example, carriages may be provided upon which specific equipment may be mounted, and/or may form part thereof. A train of carriages may be provided such that different pieces of equipment may be passed down a pipe to a predetermined location as a single train. For example, a single train may have a first carriage configured to determine location along the pipe, a second carriage configured to drill through the pipe, and a third carriage configured to deploy material through the hole. As can be appreciated, multiple pieces of equipment may be mounted on a single carriage, such that the above effects, similar effects, or different effects may be achieved with fewer (or more) carriages.

More than one carriage and/or train may be passed down a single pipe to conduct similar and/or collaborative tasks, for example at the same time at different predetermined locations along the pipe, or sequentially at different times.

Similarly, multiple carriages and/or trains may cooperate together, either by acting at the same time, or sequentially at different times, and may cooperate even in different/distinct pipes/bores, similar to any cooperation from being in the same pipe/bore. For example, if multiple bores are drilled and lined around a single asset, a respective carriage/train may be passed down each bore (e.g. to deploy material/grout simultaneously), and/or more than one carriage/train may be passed down a single bore/pipe (e.g. to provide monitoring of an asset from more than one predetermined location along the single bore/pipe).

A carriage/train may be configured to rescue a failed carriage/train, for example by supplying power, or by attaching thereto to remove it from the bore/pipe.

For the avoidance of doubt, the predetermined location may comprise a single location or a plurality of locations.

Drilling operations may be carried out from a preconstructed tunnel entrance and/or exit, an intermediately-located shaft and/or from the surface.

The bore may comprise a hole and/or shaft that is substantially circular in cross section and has a length orders of magnitude greater than its diameter. For example, each bore may have a diameter of between 100mm and 1200mm; each bore may have a length of at least 25m, at least 50m, at least 100m, at least 200m or more.

The method may comprise determining the first predetermined path (and optionally the second predetermined paths); however, this is to be done by conventional methods.

The bore may have a length of at least 25m, or less than 25m. For example, the first bore may have a length of at least 5m, 10m, 15m and/or 20m. However, other features of the second aspect may be common with the first aspect.

According to a second aspect of the present invention, there is provided a system for carrying out the method of building an underground structure according to the first aspect, the system comprising: directional drilling apparatus for drilling an underground bore through underlying geology; a pipe for lining the bore drilled by the directional drilling apparatus; pipe lining equipment for lining the bore with the pipe; cutting equipment configured to pass down the pipe to a predetermined location, and configured to cut a three-dimensional volume outside the pipe; and deployment equipment configured to pass down the pipe to the predetermined location, and configured to deploy material into the three-dimensional volume.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

is a partially cutaway perspective view of a flexible drilling arm performing coarse cutting of a three-dimensional volume from a pipe.

is a partially cutaway perspective view of a flexible drilling arm performing fine cutting of the three-dimensional volume of from the pipe.

is a partially cutaway perspective view of a region in which a tunnel is to be excavated.

is a partially cutaway perspective view of the region of immediately before excavation of the tunnel.

is a partially cutaway perspective view of the tunnel of figures 3 and 4, fully excavated.

shows an arched structure capable of being built with the method and system described herein.

shows an alternative arched structure capable of being built with the method and system described herein.

shows a further alternative arched structure capable of being built with the method and system described herein.

The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein. Likewise, method steps described or claimed in a particular sequence may be understood to operate in a different sequence.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Similarly, it is to be noticed that the term “connected”, used in the description, should not be interpreted as being restricted to direct connections only. Thus, the scope of the expression “a device A connected to a device B” should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. “Connected” may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other. For instance, wireless connectivity is contemplated.

Reference throughout this specification to “an embodiment” or “an aspect” means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, or “in an aspect” in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any one embodiment or aspect of the invention may be combined in any suitable manner with any other particular feature, structure or characteristic of another embodiment or aspect of the invention, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The use of the term “at least one” may mean only one in certain circumstances. The use of the term “any” may mean “all” and/or “each” in certain circumstances.

The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching, the invention being limited only by the terms of the appended claims.

is a partially cutaway perspective view of a bore lined with a pipe 101 through underlying geology 103. Within the pipe 101 is a movable carriage 105 from which projects a flexible drilling arm 107 through a hole 109 in a side wall of the pipe 101. The pipe 101 is shown double-walled.

The flexible drilling arm 107 is provided with a coarse cutting head 111 for roughly excavating a cavity 113.

In this and the following figures, any waste material, spoil and/or drilling fluid is omitted for clarity.

shows a fine cutting head 115, replacing the coarse cutting head 111 of , shaping the cavity 113 of into the predefined three-dimensional volume 117.

is a partially cutaway perspective view of a region of geology 201 in which a tunnel is to be excavated having an arched cross section 203. A series of lined bores 205 pass along the tunnel’s path within and beneath the arched cross section 203. The figure shows a plurality of blocks 207 that have been formed around a perimeter of the arched cross section 203. The blocks 207 are able to have been formed at the same time, as each one is spaced from each adjacent block 207, by cutting the shape of each block 207 from within adjacent pipes 205, and then filling each three-dimensional volume with grout and allowing it to harden.

shows the same region as , with additional blocks 209 formed between the existing blocks 207 in substantially the same manner.

shows the same region as figures 3 and 4, once the geological material within the arched cross section 203 has been excavated, thereby removing the bores 205 within the arched cross section 203, forming a tunnel 211. By forming the external structure with blocks first, excavation of the tunnel can be achieved without the need for a tunnelling shield or other safety systems to avoid collapse.

shows an arched structure having a similar shape of existing blocks 307 and additional blocks 309 to those shown in figures 3 to 5, but the structure being formed without a base/floor, and having inwardly-curving walls at a lower portion thereof.

shows an alternative arched structure, similar to that shown in , but having a more evenly proportioned existing blocks 407 and additional blocks 409.

shows a further alternative arched structure, similar to that shown in figures 6 and 7, but having existing blocks 507 with a diamond-shape external profile, and additional blocks 509 with an hour-glass shape external profile, such that they interlock when arranged adjacent one another.

It is to be understood that any tessellating array of blocks would be possible, whether each of the existing and additional blocks were identical, if the existing blocks were a first shape and the additional blocks were a tessellating second shape, or if each block had a unique shape.

Claims

A method of building an underground structure, the method comprising the steps of:
drilling an underground bore through underlying geology;
lining the bore with a pipe;
passing cutting equipment down the pipe to a predetermined location;
cutting a three-dimensional volume outside the pipe using the cutting equipment;
passing deployment equipment down the pipe to the predetermined location; and
deploying material into the three-dimensional volume using the deployment equipment.
The method of building an underground structure according to claim 1, wherein cutting the three-dimensional volume outside the pipe using the cutting equipment comprises performing a coarse cut with coarse cutting equipment, followed by performing a fine cut with fine cutting equipment.
The method of building an underground structure according to claim 1 or claim 2, the method further comprising the steps of:
moving the cutting equipment to a second predetermined location within the pipe;
cutting a second three-dimensional volume outside the pipe, adjacent to the first three-dimensional volume, using the cutting equipment;
moving the deployment equipment to the second predetermined location; and
deploying material into the second three-dimensional volume using the deployment equipment.
The method of building an underground structure according to claim 3, wherein the first three-dimensional volume and the second three-dimensional volume are configured to interlock with one another.
The method of building an underground structure according to any preceding claim, further comprising the steps of, prior to cutting the three-dimensional volume:
passing treatment equipment down the pipe to the predetermined location; and
deploying treatment material into the underlying geology.
The method of building an underground structure according to any preceding claim, the method further comprising the steps of, prior to cutting the three-dimensional volume:
passing perforation equipment down the bore to the predetermined location along the predetermined path; and
using the perforation equipment to make a hole at least partially through the pipe at the predetermined location.
The method of building an underground structure according to claim 6, the method further comprising the step of:
using the perforation equipment to make the hole at most only partially through the pipe at the predetermined location.
The method of building an underground structure according to any preceding claim, wherein the pipe includes the holes prior to insertion into the bore.
The method of building an underground structure according to any preceding claim, further comprising the step of introducing structural reinforcement and/or sensor devices into the volume prior to deployment of material therein.
A system for carrying out the method of building an underground structure according to any preceding claim, the system comprising:
directional drilling apparatus for drilling an underground bore through underlying geology;
a pipe for lining the bore drilled by the directional drilling apparatus;
pipe lining equipment for lining the bore with the pipe;
cutting equipment configured to pass down the pipe to a predetermined location, and configured to cut a three-dimensional volume outside the pipe; and
deployment equipment configured to pass down the pipe to the predetermined location, and configured to deploy material into the three-dimensional volume.