JPWO2020193960A5 - - Google Patents

Description

The present invention relates generally to methods and systems for constructing underground tunnels and finds particular, but not exclusive, use in tunnel construction having long kilometer extensions.

In addition to cost and speed, the main difficulty in building tunnels arises from the geology that will be encountered. In relatively short tunnels, the geology can be fairly homogeneous and planning is easy. However, long kilometer tunnels can penetrate geological regions that pose significant and potentially catastrophic problems. Ideally, the tunnel is constructed with favorable and/or homogeneous geology throughout its length. However, conventional methods involve only sampling the geology from above (if possible) along the length of the proposed tunnel and extrapolating from those samples.

A chamber with a large metallic cylindrical shield fronted by a rotating cutting wheel and in which excavated soil (optionally mixed with slurry for extraction, depending on geological/soil conditions) is accumulated. Tunnel boring machines (TBM) are known, including. Behind the chamber is a set of hydraulic jacks used to push the TBM forward against the concrete tunnel wall behind. The tunnel wall is set in segments as the TBM moves forward. Once the TBM has excavated the extension of one segment, the TBM is shut down and a new tunnel ring is erected by an erector utilizing precast concrete segments. Behind the shield, inside the finishing section of the tunnel, generally considered part of the TBM system, mud clearing section, pipelines for slurry if applicable, control room, rails for conveying precast segments. Other working mechanisms may be identified, such as. However, TBM suffers from various drawbacks, including the stop-and-start nature of tunneling and the inability of a single TBM to easily transition between different rock/soil types (particularly severely fractured and sheared rock formations). have advantages.

In addition, various directional boring techniques, such as those used in the mining, oil and gas, and construction industries. For example, horizontal drilling (HDD) is used for pipe setting and the like. HDDs can only suitably bore precise holes with a diameter of 100-1200 mm and a length of up to 800 m. Alternatively, directional drilling can be used in the oil and gas industry to drill longer holes.

The present invention seeks to overcome the disadvantages of the prior art by providing systems and methods as described below. The present invention can be used in the construction of new tunnels as well as the expansion and/or relining and/or repair of existing tunnels.

According to a first aspect of the present invention there is provided a method of constructing an underground tunnel comprising: a first bore having an extension of at least 25m along a first predetermined path through foundation geology; drilling a plurality of second bores, each along a second predetermined path through the underlying geology, each of the second predetermined paths extending between them; drilling substantially parallel to the first predetermined path to define a substantially prismatic region; and excavating material within the substantially prismatic region to form a tunnel. forming a.

In this manner, data from drilling the first bore and the plurality of second bores can be recorded and used to inform the operator of the type of material to be drilled through. Therefore, a more complete view of the underlying geology can be obtained before drilling begins.

Drilling may include directional boring, for example, a form of directional drilling used in HDDs or in the oil and gas industry.

Drilling operations can be performed from pre-built tunnel entrances and/or exits, from intermediately located shafts, and/or from the surface.

The first bore and/or each of the plurality of second bores may comprise a bore and/or shaft having a substantially circular cross-section and a girder extension greater than its diameter. For example, each bore may have a diameter of 100-1200 mm. Each bore may have an extension of at least 25m, at least 50m, at least 100m, at least 200m or more.

The method may include determining a first predetermined path (and optionally a second predetermined path). However, this is done in a conventional manner.

The substantially prismatic region may be defined solely by the plurality of second bores or may be defined by a combination of the plurality of second bores and the first bores. For example, a first bore in combination with two second bores can form a triangular prismatic region. As another example, only three secondary bores form a triangular prismatic shape, and the first bore is located within this triangular prismatic region. Alternatively, the three secondary bores may form a cubic (square prism -shaped) region with the first bore when properly positioned relative to each other.

The prismatic regions may be curved. That is, the region may have a geometric (e.g., triangular, square, etc.), regular or non-regular cross-section along its entire extension (the geometric shape and the size of the shape may vary depending on the may be constant along the extension). However, the path based on this area may not be straight, but may be curved.

The first bore may comprise a single first bore or multiple first bores (eg, two or three first bores). The first bore may comprise a lead bore. A lead bore may be spaced from the perimeter of the prismatic region and positioned through an inner portion of the prismatic region.

Data from the first bore can be collected to determine the material through which the drilling is performed.

A plurality of second bores may form the outer diameter of the tunnel. That is, multiple secondary paths may protrude along the wall of the proposed tunnel.

The cross-section of the tunnel may be circular. However, other cross-sections are possible, such as rectangular, semi-circular, arcuate, flat bottom, and the like. Circular or curved walls may improve the stability of the formed tunnel, but if this is deemed unnecessary (e.g. from data obtained from the first/second bore), a flat floor may It may be selected to facilitate easy movement of people, excavating equipment, and earthen carts.

The first and/or second bore can be lined, for example, with a (fill-in) pipe or liner. In this way the integrity of each bore can be preserved. The first bore may be lined before and/or after drilling in the plurality of second bores is completed. Similarly, at least one of the second bores may be lined before drilling of the first bore is initiated and/or after it is completed. The lining consists of lining the entire bore or lining only a portion of the bore. Any bore lining may be removed or partially removed prior to drilling.

All or some of the first and second bores can be drilled simultaneously. Or each bore can be drilled separately. This can be particularly important when drilling through soil where the integrity of each bore is at risk.

Excavation within the substantially prismatic area to form the tunnel may be carried away by the tunnel shield. The tunnel shield includes a plurality of probes at its distal end, each probe in the plurality of probes aligned with respective bores in the first bore and the plurality of second bores.

The shape of the shield matches the contour of the tunnel, ie the cross-section of the area to be excavated. These probes may be sized to fit within the first and/or second bores. In particular, these probes may be sized such that the position of each bore from a given path has some variation, for example up to 50 cm, more particularly up to 30 cm.

The extent to which unacceptable excursions occur is determined by temporarily retracting/removing the relevant probe (until such time that it can be re-engaged) and the This can be addressed by drilling with alternative means (such as a cutting head).

The probe may be equipped with (optionally interchangeable) tools. These tools allow drilling from within the first and/or second bore. In particular, for example disc cutters, cylinders or cones of rotary cutters, chainsaw-type arms with teeth suitable for the material to be worked on, high-pressure water, plow blades, and if necessary the outer and inner circumference of tunnels. A variety of different tools may be utilized for use with different materials, such as a hydraulic splitter that applies a great deal of pressure towards both to further loosen and break the material being removed.

The probe is retractable so that it can be removed or the tool replaced without requiring movement of the shield.

Fracture/collapse techniques can be used to drill soft and/or loose materials. For this type of work, the probe is matched with the plow blade as the shield advances.

As the shield advances, the laser array is used to constantly scan the newly exposed excavation surface, leaving material to protrude from the perimeter into the tunnel to impede or impede the shield's progress. We can guarantee that there will be no Ground penetrating radar may also be used in newly exposed tunnel overgrown areas.

The method further comprises removing such areas when detected, for example by using a robotic arm mounted with a pneumatic punch or replaceable cutting head, or other suitable tool. can contain.

A directional boring/drilling technique, combined with the shielding technique, can be implemented in front of each probe in the shield. This allows the shield to advance before drilling is complete.

The shield may have a beveled leading edge. The angle can be selected by conventional methods based on the nature of the material to be drilled. Specifically, the beveled leading edge slopes upwards towards the tunnel to be excavated.

The shield can be pushed in by a hydraulic ram.

The shield may comprise a dragline shield. The method may further include drawing the dragline shield through the material. The dragline shield may be a combination of tunnel shield and dragline excavator technology. A dragline excavator may include a dragline bucket suspended from a boom for positioning by the boom. A cable/rope/chain (usually controlled by a winch) is used to pull the bucket, thereby raking the material to be excavated into the bucket. The dragline shield is similarly pulled by the winch controlled cables (passed through the first and/or second bores). However, since the dragline shield is placed in the tunnel and no positioning is required, no positioning boom is required.

A dragline shield may be pulled through material by a plurality of cables. Each cable of the plurality of cables passes through each of the first bore and the plurality of second bores.

In this way, shield progress can be reliable and continuous. Each cable is attached to a respective probe. The winch may act on each cable in the plurality of cables, or two or more cables in the plurality of cables, to pull the shield forward. A winch may be provided at the opposite end (eg, open end) of the bore.

Each cable of the plurality of cables may be routed through a respective first bore and a plurality of second bores to a cable return carriage fixed downhole and returned through a respective bore to the dragline shield.

Thus, a winch may be provided behind or inside the shield to allow work on the shield before each bore is completed.

The cable return carriage may be equipped with a tightening system. The tightening system engages the wall of the bore and is installed within the bore. The tightening system may be remotely operable to engage and disengage on command so that the tightening system can be moved to new locations as needed.

Excavated soil can be continuously removed onto the loading mechanism, for example using a mechanical excavator. However, in preferred embodiments, the shield is shaped such that forward movement through the excavated tunnel lifts the excavated excavated material onto the loading mechanism. Specifically, the action of lifting excavated soil is similar to that of a bulldozer or dragline bucket.

Removal of excavated soil from the shield is by conventional methods and is returned to the tunnel floor where heavy machinery can be used. Heavy equipment may comprise zero-emission, self-supporting, electric or hydraulic towing vehicles. These vehicles may bring materials such as precast lining segments, if used, to the construction area as well as remove excavated soil. These vehicles can be configured to automatically return to charging points before resuming work if required.

The bottom bore (e.g. along the tunnel floor) is swept clean behind the point where excavation debris enters the shield so that the shield undercarriage (e.g. wheel/skid) is removed from the fill liner in place. It can navigate through rough halfpipes left in place. In this way, there is no need to set or extend the rails as the shield advances.

Any one or each bore may be lined with a liner. This liner may constitute a fill liner. This liner may constitute a solid wall. Alternatively, the liner can be pre-perforated. Thus, site time and costs can be avoided in situations where the foundation geology is understood to be good. A pre-perforated liner may include an outer sleeve that covers the perforations. In this way, substances or water may be prevented from entering the bore in an uncontrolled manner.

Equipment may penetrate the liner in a conventional manner to perform work where desired. This equipment may include a return carriage, a drilling head, and/or a drilling gun. Specifically, a piercing gun (as conventionally used in the hydraulic fracturing industry) can penetrate the liner and pierce the liner at the desired location. The piercing gun can be provided with multiple shaped charges. A punch gun may be configured to weaken material beyond the liner. That is, the charge may act to crush matter. Perforations may be provided in the liner, e.g., facing inwardly toward the prismatic -shaped region, facing outwardly away from the prismatic -shaped region, and/or traversing along the outer diameter of the prismatic -shaped region. It can be formed at a desired location.

The method may further include treating the underlying geology prior to excavating to improve the efficiency of excavating the material.

Treatment may include sonication/ hydraulic fracturing of material within the substantially prismatic region.

If the material in this area is relatively hard, pressurized water can be introduced, for example, through the holes to cause fragmentation of the material. Unlike hydraulic fracturing operations to move natural gas or oil, there is no need to introduce small particles of hydraulic fracturing proppant (either sand or aluminum oxide) to keep the fracturing section open.

By applying sonic/ hydraulic fracturing techniques through the holes, it is possible to cause fracturing only in certain predetermined directions, such as within a region.

In front of the shield, the reaming tool may penetrate the bore and break the fill lining to break/dislodge the excavated material, thereby aiding the removal process.

Treatment may include stabilizing the underlying geology outside the substantially prismatic region.

In this way, if the material outside the region is relatively fragile, contains cavities, is unstable or is submerged, the material can be stabilized. Equipment can be placed under the bore to stabilize the underlying geology.

Stabilization may be via ground freezing techniques, for example by pumping coolant through the liner and exiting the liner through holes. Freezing techniques may be temporary.

Alternatively, permanent stabilization can be achieved by injecting a chemical stabilizer, eg, via a chemical delivery nozzle (eg, within a telescoping arm). The amount and type of stabilizer used will be determined by the geology to be stabilized, cement or microcement, mineral grout (known as colloidal silica), water sensitive polyurethane (to resist water ingress). , fast-reacting foaming resins), any fast-reacting water-insensitive polyureasilicate system (expanded foam to fill voids), acrylics, jet grouting or Soilcrete® Any other material may be provided, such as an in-situ construction that hardens the soil to its designed properties, commonly known as slabs.

Stabilization of the foundation geology outside the substantially prismatic region can greatly reduce, if not prevent, further water intrusion. Any groundwater remaining within the excavated tunnel can be drained through the bottom bore.

Stabilization or weakening as described above can be provided at the same time with the shield, so ground preparation need not be completely completed before shield advance can begin.

Foundation soil stabilization outside the substantially prismatic area can be used to form the original outer structure (shell) of the tunnel prior to excavation.

Alternative and/or additional tunnel lining options include precast concrete segments (with or without waterproof lining), cast-in-place concrete (e.g., including formwork for modular shutter designs using rebar), and/or Or, for example, shotcrete, such as "shotcrete," which is applied by spraying (with or without a waterproofing membrane and optionally incorporating roof bolts, wire mesh, or steel ribs/rebar). be done.

Conceivably, the present invention could also be used with tunnel linings of wood, brickwork, masonry, pipe in tunneling, and/or cast steel/iron segments.

For example, the construction of tunnel linings, such as spray-applied waterproofing membranes (e.g., BASF® spray-applied waterproofing membranes, constitute a continuous waterproofing system, combining shotcrete and in-situ concrete). (knitted to work with a slab, facilitating the construction of composite structures), and interior finish spraying with fiber reinforced concrete. Alternatively, if the geology requires greater structural integrity, cast-in-place methods may be preferred.

The method further includes a continuous concrete molding process. Specifically, as the shield advances, the last in a series of reusable metal forms is moved forward and the old concrete has set and is poured in an almost non-stop process. can be positioned at the front followed by the installation. Water and cement are brought into the construction area and concrete can be mixed at a location near the excavation operation, possibly using excavated aggregate. The formwork is expected to be 3 or 4 pieces per section, approximately 10m long, with 10 or more segments in use. This means that in a continuous cycle, up to 90m of the tunnel behind the shield, with the formwork in place, new concrete is poured at the front and the concrete hardens at the rear where the formwork segments are formed. Means that the set is removed and passed to the front. The formwork can be passed against each other to move the units where the concrete is the oldest and hardened forward to redeploy ahead of the process. A seal between the formwork and the surface on which the concrete is poured can be made using pneumatic gaskets. Once the new formwork is installed and the gasket expands, the previous gasket will contract, thereby continuing pouring. This process can simply be repeated.

Excavated surplus material from directional boring and excavation can be used for concrete production. This concrete is pumped into the space between the tunnel skin (if a pre-assembled liner is used) and the shell, filling the void between them and further stabilizing the structure. can be made Alternatively or additionally, such excavated material (e.g. rock debris) may be concreted on site to form the tunnel lining using mobile and reusable formwork or other lining methods such as shotcrete. It can be used as part of the aggregate required to produce.

In a continuous process, a flat floor can be poured as the shield moves forward, with metal plates or structures protecting the concrete as it hardens. The shield may utilize some of the directionally drilled bores in the floor as tracks or rails (the required number is determined by the shield design). They can be filled or used for other purposes once all tunneling work has been completed and the shields have been removed.

According to a second aspect of the invention, there is provided a method of constructing an underground tunnel comprising: drilling a first bore along a first predetermined path through foundation geology; drilling a plurality of second bores each along a second predetermined path through the geology, each of the respective second predetermined paths having a substantially prismatic shape therebetween; drilling substantially parallel to the first predetermined path to define the area; and at least one of the first bore and/or the plurality of second bores through the pipe and and/or lining with a liner; and excavating material within the substantially prismatic region to form a tunnel. In this way the integrity of each bore can be preserved.

The first bore and/or the plurality of second bores may be lined with a (eg, fill-in) pipe or liner. The pipe and/or liner may be constructed of plastic materials known in the art.

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

According to a third aspect of the present invention there is provided a system for constructing an underground tunnel according to the method of the first or second aspect, the system comprising: a first bore and a plurality of second bores a directional drilling rig configured to drill a; to drill material within a substantially prismatic region defined by the first bore and the plurality of second bores to form a tunnel; a configured drilling rig.

These 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 by way of example only and is not intended to limit the scope of the invention. The reference figures mentioned below refer to the attached drawings.

FIG. 3 shows the outline of a tunnel defined by a circular bore; FIG. 10 is a side view of a bore drilled into the flank; Figure 2 shows a portion of the tunnel profile of Figure 1 showing the direction of rupture by the punch gun; Figure 4 is a view similar to Figure 3 showing a fracture formed by hydraulic fracturing; 5 is a diagram similar to FIGS. 3 and 4 showing various stabilization techniques; FIG. Figure 2 shows a completed tunnel profile similar to Figure 1; FIG. 4 is a side view of the dragline shield; FIG. 10 shows a pre-drilled fill liner for use in a bore; FIG. 12 illustrates a downhole telescoping chemical delivery carriage. FIG. 10 illustrates a downhole cable return carriage;

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 shown are only schematic and are non-limiting. Each drawing may not include all features of the invention and, therefore, should not necessarily be considered embodiments of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and related dimensions do not correspond to actual scale for the practice of the invention.

Moreover, the terms first, second, third, etc. in the specification and claims are used to distinguish between similar elements, in a ranking or any other manner, No temporal or spatial order is necessarily represented. It should be understood that the terms so used are interchangeable in appropriate circumstances and that the operations may be in any order other than that described or illustrated herein. Similarly, method steps described or claimed in a particular order may be understood to operate in a different order.

Furthermore, the terms top, bottom, above, below, etc. in the specification and claims are used for descriptive purposes and not necessarily to denote relative position. It should be understood that the terms so used are interchangeable in appropriate circumstances and that the operation may be directed in other directions than described or illustrated herein.

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 Please note. It is therefore to be construed as prescribing the presence of a stated feature, integer, step or component, but not one or more other features, integers, steps or components, or groups thereof. should be interpreted so as not to exclude the presence or addition of Therefore, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting of components A and B only. For the present invention, it means that the relevant components of the device are A and B only.

Similarly, the term "connected" as used herein should not be interpreted as being limited to direct connections only. Therefore, the scope of the phrase "device A connected to device B" should not be limited to devices or systems in which device A's output is directly connected to device B's input. This means that there is a path between the output of A and the input of B, which may be a path involving other devices or means. "Connected" means 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 still cooperate with each other. It can mean working or interacting. For example, wireless connections are contemplated.

References to "embodiments" or "aspects" throughout this specification indicate that the particular feature, structure, or characteristic described in conjunction with the embodiment or aspect is included in at least one embodiment or aspect of the invention. means Thus, the phrases "in one embodiment," "in an embodiment," or "in aspects" appearing in various places throughout this specification do not necessarily refer to all of the same embodiments or aspects. and may refer to various embodiments or aspects. Moreover, a particular feature, structure, or attribute in any one embodiment or aspect of the invention may, in any suitable manner, be disclosed in any other particular aspect of another embodiment or aspect of the invention. may be combined with any feature, structure, or characteristic of, in one or more embodiments or aspects, as will be apparent to one skilled in the art from this disclosure.

Similarly, in the description, various features of the invention are sometimes referred to as a single embodiment, drawing, or description for the purposes of simplifying the disclosure and understanding one or more of the various inventive aspects. are grouped together. 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, any individual drawing or description of an aspect need not be considered an embodiment of the present invention. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Accordingly, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate claim of this invention. As an embodiment, it stands on its own.

Further, while some embodiments described herein may include features included in other embodiments, combinations of features from different embodiments are within the scope of the invention. Meaning, and as understood by one skilled in the art, forms yet another embodiment. For example, in the following claims, any claimed embodiment can be used in any combination.

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

In the description of the present invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limits of a parameter's tolerance, in combination with an indication that one of those values is more preferred than the other, is the above alternative. Each intermediate value of the above parameter between the more preferred and less preferred values of Each value is also interpreted as an implicit expression of its own preference.

Use of the term "at least one" may mean only one in certain circumstances. The term "any" can mean "all" and/or "each" in certain circumstances.

The principles of the present invention will now be described by way of a detailed description of at least one drawing of exemplary features. Clearly, other arrangements can be constructed according to the understanding of those skilled in the art without departing from the underlying concepts or technical teachings. The invention is limited only by the terms in the appended claims.

FIG. 1 shows the outline of a tunnel defined by a circular bore. Three central lead bores 10 are drilled along the path of the tunnel. Around them, a plurality of shape-defining bores 20 are drilled to form an arched tunnel profile with a flat subfloor. The slope angle of the tunnel may be optimized for the specific requirements of the tunnel in question, eg vertical.

FIG. 2 is a side view of lead bore 10 and shape-defining bore 20 during drilling into ridge 30, the extension of each bore 10, 20 being shorter than their final extension. As can be appreciated, some of the bores are drilled concurrently with other bores, some are completed before other bores are started, and/or some are partially drilled and others are drilled simultaneously. can be interrupted while the bore is continued.

FIG. 3 is a view of a portion of the tunnel profile in FIG. 1, specifically the top left quarter including one lead bore 10 and six shape defining bores 20. FIG. The bores 10, 20 are lined with a fill lining (not shown) into which respective drilling guns (also not shown) are inserted. The piercing gun allows a shaped explosive charge to pierce the fill lining in a predetermined direction, resulting in a directed rupture 40 . The ruptures 40 shown here are from only three bores directed inwardly of the area to be drilled. However, additional perforations may be formed at the same time or later. In an alternative embodiment, the perforation gun is pneumatically operated to perforate the fill liner.

FIG. 4 is a view similar to FIG. 3 showing a fracture 50 formed by hydraulic fracturing through a hole similar to that shown in FIG.

FIG. 5 is a view similar to FIGS. 3 and 4 showing stabilization outside the drilling area via freezing 60 and via chemical injection 70 . These techniques require the use of holes directed outward away from the area to be excavated.

FIG. 6 is similar to FIG. 1 and shows the completed tunnel 100 profile on the hillside 30 of FIG. Outside the shape-defining bore 20 and excavated contour 80, the foundation geology is reinforced/stabilized to form a reinforced region 90 surrounding the tunnel. Examples of lining options that may be applied are shown with an outer concrete lining 120 . The outer concrete lining 120 is separated from the inner concrete lining 110 by a waterproof membrane 115 if necessary.

Many other tunnel lining and finishing methods are available. For example, temporary, reusable metal formwork may be installed in the tunnel. Concrete 120 is applied behind the formwork to form the smooth inner walls of the tunnel. Once the concrete 120 has fully cured, the temporary formwork can be removed and reused for another section of the tunnel, leaving smooth concrete 120 as the inner wall.

Optionally, during excavation, two bores 20 defining the shape in the floor of the tunnel are left to act as grooves/troughs 130 to guide machinery (especially dragline shields) along the tunnel. can be useful. These trenches/troughs 130 can be filled at a later date once the tunneling is completed.

FIG. 7 is a side view of the dragline shield. Arrow 200 indicates the direction of movement of the dragline shield during drilling. The profile of the dragline shield conforms to the predetermined outer tunnel shape. The angle of inclination at the leading edge 202 of the shield may be optimized for the particular requirements of the tunnel in question, eg vertical.

Propulsion of the shield through the tunnel is via a hydraulic ram 206 that pushes the dragline shield and/or at the end of the probe that extends through a lined bore to a winch that pulls the dragline shield forward. It can be done via attached cable 208 . The latter is the preferred method as it promotes continuous motion.

The shape-defining lower bore along the floor of the tunnel is swept clean behind the point where the excavation debris enters the shield, whereby the wheels 210 (or alternatively the chassis) of the dragline shield are removed from the fill liner. You can navigate through undulating halfpipes left in place. There is no need to set or extend the rails as the dragline shield advances.

A probe 204 on the distal face of the shield aligns with and extends into the shape-defining bore. Probes 204 are spaced and sized so that they engage the shape-defining bore. The dragline shield then moves forward through the defined tunnel geometry. While the bore accuracy is very precise, the probe 204 will tolerate some variation in the bore path deviating from the target course. For short ranges where unacceptable excursions occur, the probe may be re-engaged after a period of excavation by other means, such as a boom-mounted cutting head 212 found in a loadheader unit. It turns out to be backwards.

The probe 204 is equipped with interchangeable tools. Those tools allow you to be as precise or sensitive as the situation demands. These include, but are not limited to, disc cutters, rotary cutters, cylinders or cones, chainsaw-type arms with teeth suitable for excavating material, high pressure water, plow blades 214, and looser material to be removed. Both around the perimeter/perimeter of the tunnel profile and/or inward (towards the interior of the tunnel) in desired directions to break (as well as remove the fill liner of the shape defining bore). includes a hydraulic splitter 216, which can apply enormous pressure to the

Fracture/collapse techniques can be used for excavating soft and/or loose materials, especially when the outer region at the perimeter of the tunnel is stabilized to form a self-supporting shell. For this type of work, the probe is matched with the plow blade 214 as the dragline shield advances.

A laser array (not shown) constantly scans 218 the newly exposed outer surface of the excavation to ensure that no material is left protruding inward to impede or interfere with the progress of the dragline shield. Ground penetrating radar may also be used in newly exposed tunnel overgrown areas. To locate any such area, without impeding progress, one or more robotic arms 212, fitted with pneumatic drilling or replaceable cutting heads, or other suitable tools, will work on it.

Working under the protection of the dragline shield, excavated soil is continuously excavated onto the loading mechanism 222 inside the shield (assisted by the mechanical excavator 220 if necessary). Loading onto the loading mechanism 222 may be primarily by the action of a dragline shield that moves forward through excavation surplus material, like a bulldozer. Excavation surplus soil is removed by conventional methods. Excavated surplus soil is moved back on conveyor 224 where the new laying floor can be loaded with heavy equipment.

FIG. 8 is an axial cross-section and a perspective view of a pre-drilled fill liner for use in a bore. The liner has a substantially cylindrical shape with an array of holes 230 drilled from the outside to the inside.

FIG. 9 illustrates a downhole telescoping chemical delivery carriage 236 configured to move in individual bores 238 to areas requiring chemical treatment. The carriage includes five telescoping delivery probes 240 positioned around a carriage body 242, although other numbers are also contemplated. Once moved into position, the chemicals to be used are pumped into the carriage under pressure by conventional means. This pressure stretches the retractable probe and pushes it through a corresponding pre-drilled hole in the filling liner (or a hole made when the liner is in place) and into the material outside the bore. be The amount of chemical to be delivered and the area to which it is delivered are selected for each case based on the geological knowledge gained during the boring process and the final design strength required for the tunnel.

FIG. 10 is a view of the downhole cable return carriage shown in perspective with the carriage housing 250 . Disposed within the housing 250 is a tightening system 252 that engages the wall of the lined bore and is deployed therein. The clamping system 252 can be engaged or disengaged by an operator to move the carriage within the bore and lock the winch in place in preparation for use. A first end 254 of the cable is connected to the shield. A second end 256 of the cable is connected to the winch. As the winch winds the second end 256 of the cable, a series of pulleys 258 in the carriage reverse the direction of the cable so that the shield is pulled by the first end 254 of the cable.

Claims (5)

A method of constructing an underground tunnel, comprising:
drilling a first bore having an extension of at least 25 m through the foundation along a first predetermined path;
drilling a plurality of second bores through the foundation ground along respective second predetermined paths, each respective predetermined path being only the plurality of second bores; or for the combination of the plurality of second bores and the first bores to define a prismatic region having a geometrically shaped cross-section along the full extension of the first and second bores, drilling parallel to a first predetermined path, said geometry and its size being constant along the entire extension;
lining any one of the drilled first bore and the plurality of second bores with a liner having holes in the outer peripheral surface thereof;
treating the foundation ground through the hole in a particular predetermined direction prior to excavating the material to improve the efficiency of excavating material within the prismatic area ;
excavating material in said prismatic region to form a tunnel ;
The cross section of the tunnel is a cross section of the prismatic shape,
The plurality of second bores are arranged so as to cover or surround an outer peripheral surface of an excavated section of the tunnel,
The step of treating the foundation ground includes crushing a portion of material within the prismatic region through the hole, and removing the foundation ground outside the prismatic region using a coolant or a chemical stabilizer. A method comprising at least one of stabilizing . Excavation of material within said prismatic region forming a tunnel is performed by a dragline shield, said dragline shield having a plurality of probes at its distal end, each probe in said plurality of probes being pierced. each probe aligned with and inserted into respective bores in said first bore and said plurality of second bores, wherein each probe is optionally fitted with a replaceable tool, said tool being attached to each probe; 2. The method of claim 1, enabling to drill the material in the prismatic region from within the first and/or second bores. 3. The method of claim 1 or 2, wherein the treating step comprises hydraulic fracturing material within the prismatic region. A method according to any one of claims 1 to 3, wherein the treating step comprises stabilizing the foundation ground outside said prismatic area with a coolant or a chemical stabilizer . A system for constructing an underground tunnel by the method according to any one of claims 1 to 4,
a directional drilling rig configured to drill a first bore and a plurality of second bores;
a liner having a hole in an outer peripheral surface disposed in one of the drilled first bore and the plurality of second bores;
a treatment facility configured to treat foundation ground through the hole in a particular predetermined direction prior to excavating the material to improve the efficiency of excavating material within the prismatic region ;
an excavating rig configured to excavate material within the prismatic region defined by the first bore and the plurality of second bores to form a tunnel;
Treating the foundation ground includes crushing a portion of material within the prismatic region through the hole, and removing the foundation ground outside the prismatic region with a coolant or a chemical stabilizer. A system comprising at least one of stabilizing .