(19)
(11) EP 2 175 102 A2

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
14.04.2010 Bulletin 2010/15

(21) Application number: 09159275.8

(22) Date of filing: 01.05.2009
(51) International Patent Classification (IPC): 
E21F 15/10(2006.01)
E21F 13/00(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR

(30) Priority: 11.10.2008 SA 29063708

(71) Applicant: Najjah Advanced Technology Company
21492 Jeddah (SA)

(72) Inventor:
  • Binladen, Yasser Mohammed
    SA-68284, Jeddah (SA)

(74) Representative: Ketelaars, Maarten F.J.M. 
Nederlandsch Octrooibureau J.W. Frisolaan 13
2517 JS Den Haag
2517 JS Den Haag (NL)

   


(54) Method, vehicle and system for filling an underground cavity


(57) A method of filling a cavity (1) below the surface (4) of a ground area, such as a tunnel, with a solid material (12), such as stones, gravel, rock parts etc., comprises the steps of:
-providing a vehicle (9) in the cavity (1) at an initial filling location to be filled, said vehicle being equipped with a discharge means (10),
-feeding a mixture of solid material and a liquid, such as water, to the discharge means (10) provided on the vehicle (9),
-discharging the mixture (11) of liquid and solid material from the discharge means (10) at the initial filling location,
-continuing the discharge of the mixture (11) until the initial filling location is generally completely filled,
-making the vehicle (9) retract from the initial filling location to a subsequent filling location,
-discharging the mixture (11) of liquid and solid material at the subsequent filling location.




Description


[0001] The invention is related to the field of filling underground cavities with a filling material such as sand, gravel, rock etc. The cavities in question may take the form of tunnels which have been excavated for several purposes, such as for drainage, for traffic, for transport of liquids etc. Alternatively, the cavities may consist of natural hollow spaces which occur in the underground. In certain cases, it may be desirable to fill up such cavities. For instance, cavities which are located at some limited distance below the surface, may pose the risk of surface anomalies in cased the cavity in question subsides. These anomalies may include a lowering of the surface level, which lowering may amount to several centimetres up to more than a meter in the case of tunnel with a diameter of several meters located at a distance of 30 to 40 meter below surface.

[0002] The process of filling such cavities usually is complicated by the fact that they are completely filled with water. This water may originate from several sources, but generally rain water and ground water are involved. The water contains fine particles which are swirled up in case activities are carried out in the water. This makes any process for filling the cavities even more cumbersome, as the sight is reduced to zero as a result of which a reliable filling of the complete cavity is difficult to achieve.

[0003] Furthermore, it may be desirable to carry out the operation of filling a water filled underground tunnel in such a manner that the water in question is not being polluted. This excludes the application of certain polluting filling materials, such as bentonite, grout et cetera. A clean operating process may be advisable in case water sources are present within the area which contains the underground tunnel. In such cases, polluting materials such as bentonite, grout et cetera may migrate in the underground water layers and reach the water sources in question. This would result in a degradation of these water sources, and could to make the water sources unusable for certain purposes.

[0004] According to French patent 819.735, the filling of an underground tunnel is attempted by applying a flexible pipe from the ground surface to the tunnel in question. At the surface, a dough-like mixture of a liquid and particles is prepared. Said mixture is fed through the pipe while it is contained between two pigs. The lower end of the pipe is connected to a baffle which closes off the part of the tunnel to be filled. By pumping the dough-like mixture into said closed-off part of the tunnel, a filling must be obtained.

[0005] Said prior art method has several disadvantages. In the first place, said method is laborious as the tunnel has to be prepared by installing a baffle in the tunnel so as to close off the tunnel part to be filled. Furthermore, such activities make this prior art method unsuitable for bringing filling material in a tunnel which is filled with water. In particular, the materials used as filling material may include material such as mortar for obtaining the dough like mixture. As mentioned before, such materials may cause pollution in the underground water layers.

[0006] A further prior art method and apparatus for filling disused mine workings and the like is disclosed in British patent 330683. According to said publication, machines are proposed for installing gob-stuff or rubbish in minings that have been worked out. Here as well, the risk of polluting underground water layers or water sources are far from excluded.

[0007] Another prior art method and apparatus for filling the horizontal hole is disclosed in Japanese patent application 5280300. Said publication describes the cylindrical body the cross-sectional dimensions of which are identical to the cross-sectional dimensions of the hole. At the end of the cylindrical body, an introducing member has been provided with the similar cross-sectional dimensions. Through a flexible hose, muddy earth and sand are introduced in the hole while the cylindrical body and the introducing member are retracted. Such method and apparatus are not fit for treating large diameter cavities having a noncircular cross-section. Moreover, cavities containing debris cannot be filled in such a way, as the apparatus will readily become blocked when encountering debris obstacles and the like.

[0008] The object of the invention is therefore to provide a reliable method for filling underground cavities. This object is achieved by the steps of:
  • providing a vehicle in the cavity at an initial filling location to be filled, said vehicle being equipped with a discharge means,
  • feeding a flowable mixture of solid material granules, aggregates and the like and a liquid, such as water, to the discharge means provided on the vehicle,
  • discharging the mixture of liquid and solid material from the discharge means at the initial filling location,
  • continuing the discharge of the mixture until the initial filling location is generally completely filled,
  • making the vehicle retract from the initial filling location to a subsequent filling location,
  • discharging the mixture of liquid and solid material at he subsequent filling location.


[0009] In the method according to the invention, a flowable mixture of filling material and water is used. Such mixture can be obtained by mixing appropriate quantities of water and filling material, and also by selecting suitable types of filling material. Said filling material preferably comprises nodules of at least 10 mm cross-sectional dimension. The mixture is pumped to the filling location, and subsequently sprayed in the desired direction. Such spraying action can very well be carried out in underwater conditions, despite the poor visibility conditions which prevail in such case. In fact, the method may be carried out under remote control, provided suitable detection or ranging apparatus is available for checking the amount of filling at a specific location.

[0010] Furthermore, the method according to the invention has the advantage that a proper filling of the cavity can be attained irrespective of the shape and other conditions of the cavity. For instance, the cavity may have any kind of cross-section, such a circular, square or even a regular. By forming a heap of filling material, every nook and cranny of the cavity will be filled reliably. Also, the presence of debris or other obstacles will not hamper the filling process having regard to the fact that a vehicle usually is able to negotiate such obstacles.

[0011] The mixing of the water and the filling material may be carried out in several ways; preferably, this comprises the steps of:
  • providing a mixing device at the surface of the ground area,
  • feeding the mixture of solid material and liquid from the mixing device to the discharge at the vehicle.


[0012] Furthermore, the method according to the invention may comprise the steps of:
  • providing a pumping device at the surface,
  • feeding the mixture by said pumping device.


[0013] The step of feeding the mixing material may take place through several types of piping, including stiff piping. However, for the purpose of allowing some play concerning the location of the vehicle, and also for improving the manoeuvrability thereof, preference is given to the steps of:
  • feeding the mixture of solid material and liquid through a flexible hose,
  • retracting the hose together with the vehicle from the initial filling location to the subsequent filling location.


[0014] The flexible hose provides the possibility to feed the mixture at a range of different locations, and can adapt to any movements of the vehicle which may become necessary during the progress of the filling process. The hose may in fact extend directly from the pumping device to the discharge at the vehicle. With the aim of avoiding damage to the hose, the method may comprise the step of retracting the hose towards the surface while retracting the vehicle from the initial filling location to the subsequent filling location. At the surface, the hose is better protected against damaging than in the underwater environment, where visibility is usually poor as explained before.

[0015] The method according to the invention depends on the step of installing a vehicle in the tunnel. This can be carried out in case an entrance shaft extends between the cavity and the surface, in which case the method comprises the steps of:
  • lowering the vehicle through the entrance shaft into the tunnel,
  • advancing the vehicle from the shaft location to the initial filling location.


[0016] Furthermore, care should be taken to provide a regular feed to the vehicle, so as to ensure a speedy filling process. On the other hand, capital investment related to the installations required should be balanced against this requirement. A speedy process is benefited by a continuous feed of mixture to the vehicle. However, filling of the tunnel during prolonged, uninterrupted periods requires a fairly long hose, as this hose has to be retracted over the length of the location thus filled towards the surface. Transporting the mixture over fairly long distances is however rather costly, having regard to the relatively high pumping capacity which is required and also to the length of the hose required. In this connection, a compromise can be struck between a swift filling operation and acceptable capital costs by applying the steps of
  • providing at least one auxiliary shaft which extends from the surface to the tunnel,
  • introducing a flexible hose from the surface through the auxiliary shaft and towards the vehicle, said auxiliary shaft being positioned at a distance from the entrance shaft.


[0017] After the vehicle has been introduced in the tunnel through the fairly large diameter entrance shaft, a relatively narrow auxiliary shaft is used to feed the hose to the vehicle. This auxiliary shaft can have a limited diameter because it should only be wide enough to allow the passage of the hose. Thus, this auxiliary shaft can be positioned closer to the location to be filled than the entrance shaft for instance at a distance of several hundreds of meters, e.g. 300 meters. In that case, a hose of limited length can be used, which decreases costs and which also decreases the pumping power required. This step of providing an auxiliary shaft can be repeated as often as necessary. As this entails frequent introduction and retraction of the hose, the method may comprise the step of providing guide means at the auxiliary shaft for guiding the introduction and/or retraction of the hose.

[0018] Furthermore, according to the invention the type of filling material may be selected at will, and may in particular be selected to suit the demands of the environment other demands. As mentioned before, it may be desirable to avoid pollution. In this connection, according to the invention the solid material may be cleansed, e.g. heated, before it is used to make the mixture.

[0019] The particular material may be obtained in several ways, for instance by breaking stones etc so as to obtain particles of a specific maximum size. In particular, the method may comprise the step of using solid material of generally the same composition as the material of the ground surface. Furthermore, with the aim of obtaining a proper filling process, the particles of the solid material preferably have a size ranging from 10 millimetre up to 30 millimetre. The process of filling may be further in grooved by the steps of
  • providing a detection apparatus,
  • using the detection apparatus to establish the height of the material collected on the cavity bottom. In this connection, the process may also comprise the steps of:
  • using the detection apparatus to establish whether the material collected on the cavity bottom has reached the cavity ceiling,
  • making the vehicle retract upon detection of the material reaching the cavity ceiling.


[0020] The invention is also related to a vehicle for use in the method as described before, comprising a connector which is connectable to a flexible hose for feeding a mixture of water and solid material, as well as a spray member which is in flow connection with the connector and which can be directed for orienting the sprayed mixture. Said vehicle may comprise detection means, e.g. sonar, for establishing the solid material sprayed by the spray member.

[0021] The invention is furthermore related to a system for filling a cavity below ground surface, comprising a vehicle as described before, a flexible conduit means extending between the vehicle and the source of the mixture of solid material and a liquid. The flexible conduit means may comprise a flexible hose as well as a cable connected to the flexible hose at intervals along the length of the flexible conduit means. Additionally, winching means may be provided for winching in respectively paying out the cable so as to handle the hose and protect it from overloading.

[0022] The invention is furthermore related to a method of filling a cavity below the surface of a ground area, such as a tunnel, with a solid material, such as stones, gravel, rock parts etc., comprising the steps of:
  • providing a mixture of a solid material and a fluid, such as water,
  • discharging said mixture at a discharge location so as to generate a pile of solid material on the bottom of the cavity,
  • allowing the solid material to settle freely in such a way that the pile obtains a pile front at least part of which has a free slope, said pile front facing the discharge location,
  • continuing the generation of the pile until it reaches the ceiling of the cavity.


[0023] According to said method it is possible to:
  • continue the feeding of the mixture after the pile has reached the ceiling of the cavity,
  • upon continuing the feeding of the mixture make the pile front displace so as to gradually fill the cavity.


[0024] The invention will now further be described with reference to an example shown in the drawings.

Figure 1 shows a general view of the installations involved in the tunnel filling process.

Figure 2 shows a view of the installations after the tunnel filling process has progressed further.

Figure 3 shows a further view of the tunnel filling process.

Figure 4 shows a perspective view of part of the hose guiding trajectory.

Figure 5 shows a side view of part of the hose guiding trajectory in a different position.



[0025] As shown in figure 1, a tunnel shaped cavity 1 is present in the underground 2. Said cavity 1 is accessible through the entrance shaft 3, which opens out at the surface 4. The cavity 1 is filled with water, e.g. groundwater as indicated by the level 21.

[0026] A cavity in an underground may bring the risk of causing anomalies at the surface 4, in particular in case the cavity itself subsides. With the aim of reducing or removing such a risk, it is desirable to fill the cavity with filling material such as little stones, gravel etc. In the method according to the invention as shown in the figures, such material is deposited in the cavity as part of a mixture of water and filling material. To that end, a mixing device 5 is positioned at the surface 4. Water and filling material are fed into the mixing device in the required amounts, and mixed so as to take the form of a slurry which can be pumped by means of the pump 6.

[0027] Said pump 6 is connected to a flexible hose 7, which is inserted in the auxiliary shaft 16. Said flexible hose 7 runs towards a vehicle 9 near the front 8 of the cavity 1. The vehicle 9 carries a spraying device 10. By means of a connector 36, the flexible hose 7 is connected to the spraying device 10. From this spraying device 10 a mixture spray 11 is delivered, in such a way that the tunnel end gets filled completely with filling material 12. The spraying device 10 can be swung back and forth, so as to enable such complete filling of the tunnel over the full cross-section thereof. The vehicle 9 can be propelled by means of its electrically driven wheels 37. Batteries contained in the vehicle 9 serve as a power source for the electric motors of the wheels as well as for the other onboard equipment such as sensors, cameras, actuators etc.

[0028] The vehicle 9 and the spraying device 10 can be remotely controlled through the umbilical 27. This umbilical 27 extends from the vehicle 9 via a cable sheave provided on the support 30 which is situated near the entrance shaft 3, towards control equipment 33. Furthermore, the vehicle 9 is equipped with sensors and visual inspection means so as to monitor the progress of the tunnel filling process. On the basis of the signals, the crew which operates the control equipment 33 is able to manipulate the vehicle 9 and the spraying device 10 in the appropriate way.

[0029] The flexible hose 7 is guided over a ramp 15 which leads towards the upper guiding means 19, so as to obtain a smooth transition between the hose part lying on the surface 4 and the hose part which extends vertically within the auxiliary shaft 16. Similarly, at the lowest entrance of the auxiliary shaft 16, lower guiding means 18 are provided which provide a smooth transition from the vertically extending hose part in the auxiliary shaft 16 into the horizontal the extending hose part within the tunnel 1. Said guiding means 18, 19 are provided with regularly spaced rollers or sliding blocks so as to convey the flexible hose and to minimize frictional resistance forces while said hose is being pulled into the tunnel 1 by the vehicle 9.

[0030] Figure 4 shows a perspective schematic view of the hose guiding trajectory at the location of the auxiliary shaft 16. A side view is shown in figure 5, in a position which is different from figure 4 but which is similar to the position shown in figures 1-3. The upper guiding means 19 comprise two parallel curved plates 38, interconnected by a similarly curved bottom plate 39 which is welded to the edges of the plates 38. Above the bottom plate 39 and between the curved blades 38, a series of rollers and 40 is accommodated. Furthermore, two entrance rollers 41 are positioned at the entrance end and similarly two exit rollers 42 are accommodated at the exit end of the guide plates 38. It will be clear that by means of these rollers 40-42 and curved guiding plates 38, the flexible hose (not shown in figures 4 and 5) is guided properly from the ramp 15 into the auxiliary shaft 16.

[0031] The lower guiding means 18 which are positioned at the lower end of the auxiliary shaft 16 and within the tunnel 1, comprise curved guiding plates 43 interconnected by a curved bottom plate 44. At some distance above the curved bottom plate 44, a series of guide rollers 45 extends between the curved guiding plates 43. Furthermore, a short series of guide rollers 48 is positioned opposite the other series of guide rollers 46 and near the exit so as to guide the hose properly upon exiting into the tunnel 1. Entrance rollers 46 and exit rollers 47 have been used as well at the entrance end respectively the exit end of the lower guide means 18. The flexible hose is introduced between the series of rollers 45 and the curved bottom plate 44 of the lower guide means 18, whereby a proper guiding of the hose is obtained from its trajectory within the auxiliary shaft 16 towards the vehicle 9.

[0032] The aggregate will be delivered by lorries through the conveyor belt 49 into the receiving hopper 26. Through a calibrated discharge opening, said aggregate is supplied to the mixing hopper 34 through the conveyor belt 22 together with water which is fed into said mixing hopper 34 through a water supply hose 17 which is connected to the submersible pump 20 which is submerged in the water in the auxiliary shaft 16. Subsequently, the mixture thus obtained is pumped through main pump 6 and flow meter 25 into the flexible hose 7. As the mixture of water and solid material should be kept in motion, it is important to take precautions against failure of the pump 6. To that end, an emergency pump 23 has been provided which is directly connected to the water supply hose 17. In case the main pump 6 fails for whatever reason, the flow in the supply hose 7 is maintained by automatically starting the emergency pump 23 and by feeding water into said supply hose so as to empty it from solids material and to prevent clogging. The non return valves 24 ensure that no backflow can occur.

[0033] Water which is pumped out of the tunnel by means of the submersible pump 20, is fed back again into said tunnel together with the aggregate, whereby it is generally not necessary to supply additional water. Thus soiling and loss will be prevented.

[0034] While the tunnel is being filled, the front 8 of the collected filling material 12 gradually creeps towards the vehicle 9. As a result, the distance between the front 8 and the vehicle 9 gets smaller in a gradual way. For this reason, the vehicle 9 is moved back. The flexible hose 7 is pulled back as well by means of the hose pulling cable 31. At regular intervals, said hose pulling cable 31 is connected to the supply hose 7 by means of the connectors 32. The hose pulling cable is wound onto the winch 13 while pulling the flexible hose 7 backwards out of the tunnel 1 and the auxiliary shaft 16. In this process, no additional pulling forces are exerted on the flexible hose 7. At appropriate intervals, the hose pulling cable 31 is released from the flexible hose 7 by disengaging the connectors 32. This process is continued up to the phase where the front 8 comes too close to the auxiliary shaft 16. Thereafter, the vehicle can be displaced towards the other end of the tunnel (not shown), and the above process is repeated up to the phase where the tunnel 1 is completely filled.

[0035] It should be noted that the hose pulling cable 31 plays a role in the process of feeding in the flexible hose 7 into the auxiliary shaft as well. During the phase of lowering the flexible hose 7, the hose pulling cable 31 is paid out in a controllable way so as to ensure that he flexible hose 7 is not exposed to excessive pulling stresses.

[0036] An similar way of carrying out the method according to the invention is shown in figures 2 and 3. Here as well, the tunnel 1 is shown which is accessible through the entrance shaft 3. Through this entrance shaft 3, the vehicle 9 can be lowered onto the floor 14 of the tunnel 1. However, the tunnel 1 may extend over quite some distance, remote from the entrance shaft 3.

[0037] According to the invention therefore, a number of auxiliary shafts 35, 16 etc is provided, e.g. by means of drilling. The cross-sectional dimensions of these auxiliary shafts 35, 16 can remain limited, as the only purpose thereof is to run the flexible hose 7 through said shafts and to provide diver access to the tunnel. As shown in figure 2, the vehicle 9 has been moved from the remote entrance shaft 3 towards the end of the tunnel 1. After the vehicle 9 has just passed the auxiliary shaft 16, the flexible hose 7 is fed into said auxiliary shaft 16 and coupled to the vehicle coupling 36 by divers. Next, the vehicle 9 drives to the filling location, trailing the flexible hose 7 with it. Subsequently, the mixture of water and filling material is pumped through the hose 7 towards the vehicle 9 and the spraying device 10. As described before, the vehicle 9 is retracted during the progression of the front 8 of the filling 12. As soon as the vehicle 9 has come too close to the auxiliary shafts 15, the flexible hose 7 is disconnected. Subsequently, the flexible hose is run through the next auxiliary shaft 35, as shown in figure 3 and the process before is repeated. The number of auxiliary shafts may be selected depending on the length of the tunnel and of the flexible hose length.

[0038] Under normal circumstances, the vehicle 9 is able to propel itself forwards and backwards by its electric motors and batteries. However, in the event of a control or power failure, the vehicle should be safely recoverable through the entrance shaft 3. To that end, a vehicle pulling cable 28 is connected to the vehicle 9. Said vehicle pulling cable 28 is guided over an appropriate cable sheave on the support 30, described before, and is wound onto the winch 29. By pulling the vehicle pulling cable 28, the vehicle 9 is pulled backwards towards the entrance shaft 3, and subsequently the vehicle 9 can be lifted out of the said entrance shaft 3. The flexible hose 7 has been disconnected before this recovery process of the vehicle is carried out.

[0039] As mentioned before, the flow of the mixture which is fed into the flexible hose 7 is monitored by the flow meter 25. A flow meter has been provided on the vehicle 9 as well. The data obtained through these flow meters is constantly being compared. In case the flow meter mounted on the vehicle 7 indicates that an amount of mixture is delivered to the vehicle 9 which is less than the amount of mixture which is delivered at the surface, an alarm signal is given. This difference in flow indicates that at some point along the length of the flexible hose, a damage has occurred which leads to loss of mixture. Divers are sent into the tunnel to repair this damage so as to prevent any clogging of the tunnel, which would lead to the vehicle becoming lost behind the aggregate collecting at the location of the damaged hose.

[0040] Furthermore, the vehicle is provided with sonar devices at its front end and at its back end. These sonar devices are used to control the vehicle in such a way that it can always be positioned in the middle of the tunnel. Furthermore, a so-called profiler has been provided on the vehicle, which detects the degree of filling at the filling location. Furthermore, height meters are provided so as to establish the height of the spraying device 10 with respect to the tunnel ceiling and the tunnel floor. Also, video cameras and lighting devices are provided so as to inspect the filling location in case the visibility is good. Such good visibility usually occurs only at the start of the activities, after the particles in the water have had time overnight to settle.

[0041] The invention may also be carried out according to the following clauses.

Clauses



[0042] 

Clause 1. Method of filling a cavity (1) below the surface (4) of a ground area, such as a tunnel, with a solid material (12), such as stones, gravel, rock parts etc., comprising the steps of:

  • providing a vehicle (9) in the cavity (1) at an initial filling location to be filled, said vehicle being equipped with a discharge means (10),
  • feeding a mixture of solid material and a liquid, such as water, to the discharge means (10) provided on the vehicle (9),
  • discharging the mixture (11) of liquid and solid material from the discharge means (10) at the initial filling location,
  • continuing the discharge of the mixture (11) until the initial filling location is generally completely filled,
  • making the vehicle (9) retract from the initial filling location to a subsequent filling location,
  • discharging the mixture (11) of liquid and solid material at the subsequent filling location.

Clause 2. Method according to clause 1, comprising the steps of:

  • providing a mixing device (5) at the surface (4) of the ground area,
  • feeding the mixture of solid material and liquid from the mixing device (5) to the discharge (10) at the vehicle (9).

Clause 3. Method according to clause 1 or 2, comprising the steps of:

  • providing a pumping device (6) at the surface (4),
  • feeding the mixture by said pumping device (6).

Clause 4. Method according to any of clauses 1-3, comprising the steps of:

  • feeding the mixture of solid material and liquid through a flexible hose (7),
  • retracting the flexible hose (7) together with the vehicle (9) from the initial filling location to the subsequent filling location.

Clause 5. Method according to clauses 3 and 4, comprising the step of:

  • making the flexible hose (7) extend between the pumping device (6) and the discharge (10) at the vehicle (9).

Clause 6. Method according to clauses 4 or 5, comprising the step of:

  • retracting the flexible hose (7) towards the surface (4) while retracting the vehicle (9) from the initial filling location to the subsequent filling location.

Clause 7. Method according to any of clauses 4-6, comprising the steps of:

  • providing a hose pulling cable (31),
  • connecting the flexible hose (7) at specific intervals along its length to the hose pulling cable (31),
  • retracting the flexible hose (7) by exerting a pulling force on the hose pulling cable (31).

Clause 8. Method according to clause 7, comprising the step of retracting the hose pulling cable (31) by winding onto a winch (13).

Clause 9. Method according to any of the preceding clauses, wherein an entrance shaft (3) extends between the cavity (1) and the surface (4), comprising the steps of:

  • lowering the vehicle (9) through the entrance shaft (3) into the tunnel (1),
  • advancing the vehicle (9) from the entrance shaft (3) location to the initial filling location.

Clause 10. Method according to clause 9, comprising the steps of:

  • providing at least one auxiliary shaft (35, 16) which extends from the surface (4) to the tunnel (1),
  • introducing a flexible hose (7) from the surface (4) through the auxiliary shaft (35, 16) and towards the vehicle (9), said auxiliary shaft (35, 16) being positioned at a distance from the entrance shaft (3).

Clause 11. Method according to clause 10, comprising the step of:

  • providing guide means (18, 19) at the auxiliary shaft (35, 16) for guiding the introduction and/or retraction of the flexible hose (7).

Clause 12. Method according to clause 11, comprising the step of:

  • selecting a distance between the neighbouring entrance shaft (3) and the auxiliary shaft (35, 16), and between neighbouring auxiliary shafts (35, 16), of several hundreds of meters, e.g. 300 meters.

Clause 13. Method according to any of the preceding clauses, wherein the cavity (1) is filled with a liquid, such as water, comprising the step of evacuating the liquid from the cavity (1) upon filling said cavity with solid material (12).

Clause 14. Method according to any of the preceding clauses, wherein the solid material (12) is cleaned, e.g. heated, before it is used to make the mixture.

Clause 15. Method according to any of the preceding clauses, wherein the solid material (12) is obtained by breaking stones etc so as to obtain particles of a specific maximum size.

Clause 16. Method according to any of the preceding clauses, wherein the particles of the solid material (12) have a size ranging from 10 millimetre up to 30 millimetre.

Clause 17. Method according to any of the preceding clauses, comprising the step of using solid material (12)of generally the same composition as the material of the ground surface.

Clause 18. Method according to any of the preceding clauses, comprising the steps of:

  • providing a detection apparatus,
  • using the detection apparatus to establish the height of the material collected on the cavity bottom (14).

Clause 19. Method according to clause 18, comprising the steps of:

  • using the detection apparatus to establish whether the material collected on the cavity bottom (14) has reached the cavity ceiling,
  • making the vehicle (9) retract upon detection of the material reaching the cavity ceiling.

Clause 20. Vehicle (9) for use in the method according to any of the preceding clauses, comprising a connector (36) which is connectable to a flexible hose (7) for feeding a mixture of water and solid material (12), as well as a spray member (10) which is in flow connection with the connector (36) and which is carried for directing the sprayed mixture (11).

Clause 21. Vehicle (9) according to clause 20, comprising detection means, e.g. sonar and profilers, for establishing the solid material sprayed by the spray member (10).

Clause 22. Vehicle (9) according to clause 20 or 21, comprising wheels (37) which are electrically driveable.

Clause 23. Vehicle (9) according to any of clauses 20-22, wherein the drive means for directing the spray member (10) are actuated electrically.

Clause 24. System for filling a cavity below ground surface, comprising a vehicle (9) according to any of clauses 20-23, a flexible conduit means (7, 31) extending between the vehicle (9) and the source (34) of the mixture of solid material (12) and a liquid.

Clause 25. System according to clause 24, wherein the flexible conduit means comprises a flexible hose (7) as well as a hose pulling cable (31) connected to the flexible hose (7) at intervals along the length of the flexible hose (7).

Clause 26. System according to clause 23 or 24, comprising winching means (13) for winching in respectively paying out the hose pulling cable (31).

Clause 27. System according to any of clauses 20-26, comprising an umbilical (27) which is connected to the vehicle (9) and to remote control equipment (33) for controlling the vehicle (9).

Clause 28. System according to any of clauses 20-27, comprising a vehicle pulling cable (28) as well as a winch (29) for pulling the vehicle pulling cable (28).

Clause 29. System according to any of clause 20-28, comprising curved guide means (18, 19) for guiding the flexible hose according to curved trajectories.

Clause 30. System according to any of clauses 20-29, comprising guide means (30) for guiding the umbilical (27) and the vehicle pulling cable (28) according to curved trajectories.

Clause 31. Method of filling a cavity (1) below the surface (4) of a ground area, such as a tunnel, with a solid material (12), such as stones, gravel, rock parts etc., comprising the steps of:

  • providing a mixture of a solid material (12) and a fluid, such as water,
  • discharging said mixture at a discharge location so as to generate a pile of solid material on the bottom of the cavity,
  • allowing the solid material to settle freely in such a way that the pile obtains a pile front at least part of which has a free slope, said pile front facing the discharge location,
  • continuing the generation of the pile until it reaches the ceiling of the cavity.

Clause 32. Method according to clause 31, comprising the steps of:

  • continuing the feeding of the mixture after the pile has reached the ceiling of the cavity (1),
  • upon continuing the feeding of the mixture making the pile front displace so as to gradually fill the cavity.


List of reference numerals



[0043] 
1.
Tunnel
2.
Underground
3.
Entrance shaft
4.
Surface
5.
Mixing device
6.
Pump
7.
Flexible hose
8.
Front of filling material
9.
Vehicle
10.
Spraying device
11.
Mixture spray
12.
Filling material
13.
Winch
14.
Bottom of tunnel
15.
Ramp
16.
Auxiliary shaft
17.
Water supply hose
18.
Lower guiding means
19.
Upper guiding means
20.
Submersible pump
21.
Water level
22.
Conveyor belt
23.
Emergency pump
24.
Non return valves
25.
Flow meter
26.
Receiving hopper
27.
Umbilical
28.
Vehicle pulling cable
29.
Winch
30.
Support
31.
Hose pulling cable
32.
Cable connector
33.
Control equipment
34.
Mixing hopper
35.
Auxiliary shaft
36.
Connector
37.
Electrically driven wheels
38.
Curved guiding plate upper guiding means
39.
Curved bottom plate upper guiding means
40.
Series of guide rollers upper guiding means
41.
Entrance rollers upper guiding means
42.
Exit rollers upper guiding means
43.
Curved guiding plate lower guiding means
44.
Curved bottom plate lower guiding means
45.
Series of guide rollers lower guiding means
46.
Entrance rollers lower guiding means
47.
Exit rollers lower guiding means
48.
Short series of guide rollers lower guiding means
49.
Conveyor belt



Claims

1. Method of filling a cavity (1) below the surface (4) of a ground area, such as a tunnel, with a solid material (12), such as stones, gravel, rock parts etc., comprising the steps of:

- providing a vehicle (9) in the cavity (1) at an initial filling location to be filled, said vehicle being equipped with a discharge means (10),

- feeding a mixture of solid material and a liquid, such as water, to the discharge means (10) provided on the vehicle (9),

- discharging the mixture (11) of liquid and solid material from the discharge means (10) at the initial filling location,

- continuing the discharge of the mixture (11) until the initial filling location is generally completely filled,

- making the vehicle (9) retract from the initial filling location to a subsequent filling location,

- discharging the mixture (11) of liquid and solid material at the subsequent filling location.


 
2. Method according to claim 1, comprising the steps of:

- providing a mixing device (5) at the surface (4) of the ground area,

- feeding the mixture of solid material and liquid from the mixing device (5) to the discharge (10) at the vehicle (9).


 
3. Method according to claim 1 or 2, comprising the steps of:

- providing a pumping device (6) at the surface (4),

- feeding the mixture by said pumping device (6).


 
4. Method according to any of claims 1-3, comprising the steps of:

- feeding the mixture of solid material and liquid through a flexible hose (7),

- retracting the flexible hose (7) together with the vehicle (9) from the initial filling location to the subsequent filling location.


 
5. Method according to claim 4, comprising the steps of:

- providing a hose pulling cable (31),

- connecting the flexible hose (7) at specific intervals along its length to the hose pulling cable (31),

- retracting the flexible hose (7) by exerting a pulling force on the hose pulling cable (31).


 
6. Method according to any of the preceding claims, wherein an entrance shaft (3) extends between the cavity (1) and the surface (4), comprising the steps of:

- lowering the vehicle (9) through the entrance shaft (3) into the tunnel (1),

- advancing the vehicle (9) from the entrance shaft (3) location to the initial filling location.


 
7. Method according to claim 6, comprising the steps of:

- providing at least one auxiliary shaft (35, 16) which extends from the surface (4) to the tunnel (1),

- introducing a flexible hose (7) from the surface (4) through the auxiliary shaft (35, 16) and towards the vehicle (9), said auxiliary shaft (35, 16) being positioned at a distance from the entrance shaft (3).


 
8. Method according to claim 7, comprising the step of:

- providing guide means (18, 19) at the auxiliary shaft (35, 16) for guiding the introduction and/or retraction of the flexible hose (7).


 
9. Method according to any of the preceding claims, wherein the cavity (1) is filled with a liquid, such as water, comprising the step of evacuating the liquid from the cavity (1) upon filling said cavity with solid material (12).
 
10. Method according to any of the preceding claims, comprising the steps of:

- providing a detection apparatus,

- using the detection apparatus to establish the height of the material collected on the cavity bottom (14).


 
11. Vehicle (9) for use in the method according to any of the preceding claims, comprising a connector (36) which is connectable to a flexible hose (7) for feeding a mixture of water and solid material (12), as well as a spray member (10) which is in flow connection with the connector (36) and which is carried for directing the sprayed mixture (11).
 
12. System for filling a cavity below ground surface, comprising a vehicle (9) according to claims 11, a flexible conduit means (7, 31) extending between the vehicle (9) and the source (34) of the mixture of solid material (12) and a liquid.
 
13. System according to claim 12, wherein the flexible conduit means comprises a flexible hose (7) as well as a hose pulling cable (31) connected to the flexible hose (7) at intervals along the length of the flexible hose (7).
 
14. System according to claim 12 or 13, comprising guide means (30) for guiding the umbilical (27) and the vehicle pulling cable (28) according to curved trajectories.
 
15. Method of filling a cavity (1) below the surface (4) of a ground area, such as a tunnel, with a solid material (12), such as stones, gravel, rock parts etc., comprising the steps of:

- providing a mixture of a solid material (12) and a fluid, such as water,

- discharging said mixture at a discharge location so as to generate a pile of solid material on the bottom of the cavity,

- allowing the solid material to settle freely in such a way that the pile obtains a pile front at least part of which has a free slope, said pile front facing the discharge location,

- continuing the generation of the pile until it reaches the ceiling of the cavity.


 




Drawing

















Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description