Obstacle breaking device and obstacle breaking method

Abstract

To provide an obstacle crushing apparatus capable of rapidly crushing an obstacle to a size capable of being taken in by the screw conveyor provided to the back of a chamber even when a large-sized obstacle is taken in the chamber, and an obstacle crushing method.SOLUTION: An obstacle breaking device 100 for breaking an obstacle taken into a chamber of a tunnel boring machine includes an outer pipe 30 extending into a chamber 10 through an insertion hole 13 of a partition wall 12, an inner pipe 40 partially protruding from a distal end 31 of the outer pipe 30 and having a high-pressure injection nozzle 47, a rotating device 50 for rotating the inner pipe 40, and a packer 49 attached to a protruding region 44 of the inner pipe 40 protruding from the distal end 31 of the outer pipe 30. The pressure in the sealed space K is accumulated by the high-pressure injection to the sealed space K between the bottomed hole H and the inner pipe 40.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an obstacle breaking device and an obstacle breaking method. [Background technology]

[0002] When constructing a shield tunnel by digging a shield machine, there is a trend toward longer and deeper shield tunnels, and as a result, there are cases where unexpected strata are encountered during shield construction.In such unexpected strata, it is common for unexpectedly large boulders and other objects to be drawn into the chamber at the back of the cutter head through the opening. If large boulders or other objects that are taken into the chamber in this way remain inside the chamber and are not discharged onto a screw conveyor extending to the rear of the shield tunneling machine's interior through a shutter gate or the like located below the bulkhead that forms the chamber, this may hinder continued tunneling. As such, large boulders and large concrete shells remaining in the ground can become obstacles to the shield tunneling machine when it excavates, and therefore are referred to as "obstacles" in this specification.

[0003] Therefore, what is needed is an obstacle crushing device and method that can quickly crush large obstacles into sizes that can be taken in by the screw conveyor at the back of the chamber, even if the large obstacles are taken into the chamber.

[0004] Patent Document 1 proposes a slurry shield machine that removes gravel obstacles that the machine encounters during excavation from the front of the excavation. This slurry shield machine is equipped with a cutter face that is rotatably mounted at the front end of the shield frame and has the required number of slits for catching debris, a mud feeding means to a pressure chamber defined on the back side of the cutter face, and a mud discharge means from this pressure chamber, and a water jet nozzle is attached to the cutter face with an opening facing the outer periphery of the front face. High-pressure water is sprayed from a water jet nozzle attached to the cutter face into the ground surrounding a gravel obstacle in front of it, eroding the ground and, as the ground is eroded, moving the gravel obstacle from its front position toward the outer periphery of the cutter face, removing the gravel obstacle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-127378 Summary of the Invention [Problem to be solved by the invention]

[0006] The slurry shield machine described in Patent Document 1 is said to be able to easily remove gravel obstacles in front of the cutter face from the front position of the cutter face toward the outer periphery in a short period of time. However, it does not disclose a solution to the above-mentioned problem, i.e., a means for quickly breaking down large obstacles into pieces that can be taken in by the screw conveyor at the back of the chamber when they are taken into the chamber.

[0007] The object of the present invention is to provide an obstacle crushing device and an obstacle crushing method that can quickly crush large obstacles into a size that can be taken in by a screw conveyor at the back of the chamber, even when the large obstacles are taken into the chamber. [Means for solving the problem]

[0008] In order to achieve the above object, one aspect of the obstacle breaking device according to the present invention is: An obstacle breaking device for a shield tunneling machine, comprising: a main body; a cutter head that rotates forward in the excavation direction of the main body; and a partition wall that forms a chamber together with the cutter head inside the main body, the obstacle breaking device breaking up an obstacle that has been taken into the chamber, an outer tube extending into the chamber through a through hole formed in the partition wall; an inner tube that is inserted into the outer tube, a portion of which protrudes from a tip of the outer tube, and is equipped with a high-pressure injection nozzle; a rotating device that rotates the inner tube; a packer attached to a protruding region around the inner pipe that protrudes from the tip of the outer pipe; The packer, which is disposed inside a bottomed hole created by drilling the obstacle with high-pressure jet from the high-pressure jet nozzle rotated by the rotating device, expands when pushed by the outer pipe, and pressure in the sealed space formed between the bottomed hole and the inner pipe is accumulated by high-pressure jet from the high-pressure jet nozzle into the sealed space.

[0009] According to this aspect, the outer pipe extends into the chamber through an insertion hole opened in the partition wall, an inner pipe equipped with a high-pressure injection nozzle is inserted into the inside of the outer pipe with a part of it protruding from the tip of the outer pipe, and a packer is attached to the protruding area protruding from the tip of the outer pipe around the inner pipe, and the packer is pushed by the outer pipe into the bottomed hole created by drilling the obstacle with the high-pressure injection and expands, and the obstacle can be quickly crushed by the accumulation of pressure due to the high-pressure injection in the sealed space between the bottomed hole and the inner pipe. The obstacles that have been crushed to smaller sizes can be smoothly discharged onto the screw conveyor through a shutter gate or the like provided in the chamber.

[0010] The inner pipe has two ends that extend from the front and rear ends of the outer pipe, and a rotating device is attached to the inner pipe that extends from the rear end of the outer pipe. Driving the rotating device rotates the inner pipe, and a high-pressure jet nozzle attached to the tip of the inner pipe rotates and high-pressure jets of water or other fluid are sprayed to drill the hole. Obstacles here include boulders, concrete shells, etc. Furthermore, while a "boulder" geologically refers to a boulder with a particle size of 256 mm or more, in this specification, "boulder," "large boulder," and "large obstacle" refer to an obstacle of such size that it is difficult to discharge it from the chamber onto a belt conveyor in, for example, an earth pressure shield tunneling machine.

[0011] Another aspect of the obstacle breaking device according to the present invention is An insertion tube including an opening / closing valve is attached to the rear surface of the partition wall at a position corresponding to the insertion hole, and the outer tube and the inner tube inserted into the insertion tube extend into the chamber through the opening and closing valve in an open position.

[0012] According to this aspect, the outer tube and inner tube are inserted into an insertion tube including an opening / closing valve attached at a position corresponding to the insertion hole on the back surface of the partition wall, and extend into the interior of the chamber through the insertion hole via the opening / closing valve in the open position.This allows the outer tube and inner tube to communicate between the interior of the chamber and the interior of the machine at the back surface of the chamber, which have different air pressures, and when the outer tube is not inserted into the insertion hole, the interior of the chamber can be completely isolated from the interior of the machine.

[0013] Another aspect of the obstacle breaking device according to the present invention is A pre-bender is attached to the end of the insertion tube, the outer tube is inserted into the pre-bender while being sealed between the pre-bender, and the insertion tube is inserted into the opening and closing valve.

[0014] According to this aspect, the outer tube is inserted into the insertion tube and the opening / closing valve while being sealed between the insert tube and the pre-bender attached to the end of the insertion tube, so that the outer tube can be extended from inside the machine into the chamber through the partition while ensuring watertightness.

[0015] Another aspect of the obstacle breaking device according to the present invention is A guide rod is attached to the back surface of the partition or the insertion tube, an inner tube feeding device that feeds at least the inner tube is attached to the guide rod so as to be slidable; The inner tube feeding device slides at a constant speed to feed out the inner tube.

[0016] According to this embodiment, a guide rod is attached to the back of the partition wall or to the insertion tube attached to the partition wall, and an inner tube feed device is attached to the guide rod so that it can slide freely.The inner tube feed device slides at a constant speed, pushing the inner tube in a rotating position into an obstacle at a constant speed to drill a hole.By doing this, the bottomed hole drilled by high-pressure water or the like sprayed from a rotating nozzle can be formed so that the drilling diameter is approximately the same along the drilling length, and the unevenness of the hole wall can be minimized. For example, if the pushing speed is different, the unevenness of the hole wall of the bottomed hole formed in boulders or the like tends to increase, which is undesirable because it makes it difficult for the packer to adhere to the hole wall and form an enclosed space.

[0017] Here, "the inner tube feeding device feeds out at least the inner tube" means that the inner tube feeding device feeds out both the inner tube and the outer tube, in addition to feeding out only the inner tube. In the latter case, it includes a feeding mode in which the inner tube feeding device feeds out both the outer tube and the inner tube up to a boulder or the like in the chamber, and then feeds (makes the inner tube extend out from) the outer tube to drill a bottomed hole in the boulder or the like.

[0018] Another aspect of the obstacle breaking device according to the present invention is An outer tube feeding device is attached to the end of the insertion tube, The outer tube is fed by the outer tube feeding device.

[0019] According to this aspect, the outer tube is fed into the chamber by an outer tube feeding device attached to the end of the insertion tube attached to the bulkhead, and the outer tube feeding device functions to prevent buckling, in which the outer tube is pushed into the inside of the machine due to the pressure inside the chamber, while feeding the outer tube into the chamber, pushing in the packer and causing it to expand sideways.

[0020] Another aspect of the obstacle breaking device according to the present invention is The packer is made of nitrile rubber.

[0021] According to this aspect, since the packer is made of nitrile rubber, it is possible to impart appropriate flexibility and hardness to the packer, and therefore the inflated packer comes into close contact with the uneven hole wall and easily forms an airtight space, and even after pressure has built up in the airtight space, the hard packer can maintain the airtight space against the pressure, and the built-up pressure can introduce cracks into obstacles such as boulders, making it possible to crush them smoothly.

[0022] Furthermore, one aspect of the obstacle crushing method according to the present invention is to 1. A method for crushing an obstacle taken into a chamber in a shield tunneling machine comprising: a main body; a cutter head that rotates forward in the excavation direction of the main body; and a partition wall that forms a chamber together with the cutter head inside the main body, the method comprising: an inner pipe having a high-pressure injection nozzle at its tip is inserted into the outer pipe, a portion of the inner pipe is protruded from the tip of the outer pipe, a packer is attached to the periphery of the inner pipe in a protruding region protruding from the tip of the outer pipe, and the outer pipe and the inner pipe are extended into the chamber through an insertion hole opened in the partition wall; The inner tube is rotated, and a bottomed hole is drilled in the obstacle by high-pressure jet from the rotating high-pressure jet nozzle. The packer is disposed inside the bottomed hole, and the outer pipe pushes and inflates the packer, thereby forming an enclosed space between the bottomed hole and the inner pipe, and high-pressure injection from the high-pressure injection nozzle is applied to the enclosed space, thereby accumulating pressure in the enclosed space and crushing the obstacle.

[0023] According to this aspect, an outer tube is extended into the chamber through an insertion hole opened in the partition, an inner tube equipped with a high-pressure injection nozzle at its tip is inserted into the interior of the outer tube so that a portion of the inner tube protrudes from the tip of the outer tube, a packer is attached to the protruding region protruding from the tip of the outer tube around the inner tube, the high-pressure injection nozzle is rotated and high-pressure injected to drill a hole in the obstacle, the packer is placed inside the hole, and the packer is pushed in by the outer tube to inflate it, and high-pressure injection is applied from the high-pressure injection nozzle to the sealed space between the hole and the inner tube to accumulate pressure, thereby smoothly crushing the obstacle. Obstacles that have been crushed into smaller pieces can be smoothly discharged onto a screw conveyor through a shutter gate or the like installed in the chamber. Therefore, even if large boulders or other large objects are taken into the chamber, the boulders or other large objects can be quickly crushed and discharged as smaller pieces, allowing the shield tunneling machine to continue excavating. [Effects of the Invention]

[0024] According to the obstacle breaking device and obstacle breaking method of the present invention, even if a large obstacle is taken into the chamber, the obstacle can be quickly broken down into a size that can be taken in by the screw conveyor at the back of the chamber. [Brief explanation of the drawings]

[0025] [Figure 1] 1A and 1B are diagrams illustrating an example of an obstacle breaking device according to an embodiment in a pre-formation state and boulders to be broken in a chamber. [Figure 2] FIG. 10 is a diagram showing an example of an obstacle breaking device according to an embodiment, illustrating a state in which the tip of the fed inner pipe has reached a boulder. [Figure 3] 10 is a diagram showing a state in which an example of an obstacle breaking device according to an embodiment is drilling a boulder to form a bottomed hole. FIG. [Figure 4] FIG. 10 is a diagram showing a state in which a packer expands laterally inside a bottomed hole to form an enclosed space. [Figure 5] FIG. 10 is a diagram showing a state in which pressure builds up in an enclosed space and boulders are crushed. [Figure 6] FIG. 1 is a diagram showing an experimental device used in a demonstration experiment. [Figure 7] FIG. 1 is a photograph showing granite, which is the test specimen to be crushed in the demonstration experiment. [Figure 8A] FIG. 10 is a photograph showing the hole wall of the bottomed hole when the inner tube is manually fed. [Figure 8B] FIG. 10 is a photograph showing the hole wall of a bottomed hole when the inner tube is mechanically fed. [Figure 9] FIG. 10 is a photograph showing the state in which the test specimen is crushed in the demonstration experiment. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an obstacle breaking device and an obstacle breaking method according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components are designated by the same reference numerals, and redundant description may be omitted.

[0027] [Obstacle Breaking Device and Obstacle Breaking Method According to the Embodiment] First, an example of an obstacle breaking device and an obstacle breaking method according to an embodiment will be described with reference to FIGS. Here, Fig. 1 is a diagram showing an example of an obstacle breaking up device according to an embodiment in a state before formation and a boulder to be broken up that is in a chamber. Fig. 2 is a diagram showing an example of an obstacle breaking up device according to an embodiment, showing a state in which the tip of the delivered inner pipe has reached the boulder. Fig. 3 is a diagram showing a state in which an example of an obstacle breaking up device according to an embodiment has drilled a boulder and formed a bottomed hole. Fig. 4 is a diagram showing a state in which a packer has expanded laterally inside the bottomed hole, forming an enclosed space. Fig. 5 is a diagram showing a state in which pressure has accumulated in the enclosed space and the boulder has been broken up.

[0028] Figures 1 to 5 show an enlarged view of a portion of a bulkhead 12 that forms a chamber 10 together with a cutter head (not shown) that rotates forward in the excavation direction of the main body of a shield tunneling machine that excavates the ground, and also show an enlarged view of a portion of the chamber 10 of the bulkhead 12 and a portion of the interior of the machine 15.

[0029] Below the partition wall 12 is a shutter gate (not shown) that can be opened and closed freely, and inside the machine 15, a screw conveyor (not shown) extends rearward from the shutter gate, allowing the excavated soil that has been stirred and plastically fluidized inside the chamber 10 to be discharged.

[0030] The following description will be given assuming that an unexpectedly large boulder G (an example of an obstacle) has been taken into chamber 10 at the back of a cutter head (not shown) through an opening in the cutter head. Note that the boulder G in the illustrated example is large enough that it cannot be discharged by a screw conveyor through a shutter gate (not shown), and since the boulder G remaining inside chamber 10 can make it difficult for the shield machine to continue excavating, the following description will describe an apparatus and method for crushing the boulder G inside chamber 10 to a size that can be discharged, thereby enabling the shield machine to continue excavating.

[0031] 1, a through-hole 13 is formed in the bulkhead 12, and one end 20a of a through-pipe 20 equipped with an on-off valve 24 is attached by welding or bolting to a position on the back surface 12a of the bulkhead 12 corresponding to the through-hole 13. The diameter of the through-hole 13 may be, for example, about 2 to 3 inches.

[0032] A flange 22 and a prepender 28 are attached to the other end 20b of the insertion tube 20, and a bolt hole 22a is formed in the flange 22. As will be described below, a bolt 75 (see FIG. 4) constituting the outer tube feed device 70 is screwed into this bolt hole 22a.

[0033] 1, the opening / closing valve 24 is closed to prevent muddy water, groundwater, etc. in the chamber 10 from leaking into the interior of the machine 15. In this way, the state in which the outer pipe 30 is not inserted into the insertion pipe 20 occurs during the process of assembling the obstacle breaking up device 100 as shown in FIG. 1, or at the stage in which the outer pipe 30 is pulled out of the insertion pipe 20 into the interior of the machine 15 after the breaking up of the boulder G is completed, and therefore the opening / closing valve 24 is closed each time.

[0034] As shown in Figure 2, an outer tube 30 is inserted into the insertion tube 20 via a prepender 28 attached to the other end 20b, and the outer tube 30 is inserted through the opening / closing valve 24 which is open in the X1 direction, and one end 31 (tip) of the outer tube 30 is extended into the interior of the chamber 10 through the insertion hole 13 of the partition wall 12.

[0035] As shown in the illustrated example, the outer pipe 30 is sealed between the prepender 28 and inserted into the prepender 28 and the insertion tube 20, with a portion of it protruding into the chamber 10, making it possible to send the outer pipe 30 into the chamber 10 while preventing muddy water, etc. in the chamber 10 from leaking into the interior of the machine 15.

[0036] An inner pipe 40 is inserted inside the outer pipe 30, and a protruding region 44 in front of the inner pipe 40 protrudes from one end 31 of the outer pipe 30. A joint pipe 45 is connected to the tip of the protruding region 44, and a high-pressure injection nozzle 47 (rotating nozzle) is connected to the joint pipe 45.

[0037] A packer 49 is attached around the protruding region 44 of the inner pipe 40 , and one end 49 a of the packer 49 abuts against one end 31 of the outer pipe 30 .

[0038] A guide rod 60 is disposed below the insertion pipe 20 on the back surface 12a of the bulkhead 12, and one end 61 of the guide rod 60 is welded or bolted to the back surface 12a. Also, a steel support 62 is attached below the guide rod 60 to support the base of the guide rod 60 (the portion connected to the back surface 12a).

[0039] An inner tube feed device 65 incorporating multiple rollers 67 that move along the guide rod 60 and an actuator (motor, etc.) not shown that rotates and drives each roller 67 is attached to the guide rod 60 so as to be able to slide freely.

[0040] One end 41 (rear end) of the inner tube 40 is attached to the rotation shaft of the rotation device 50, and when the rotation device 50 is driven, the outer tube 30 does not rotate, but the inner tube 40 rotates around its axis in the X3 direction (see Figure 3). Here, the inner tube 40 may be a single tube or a double tube, and the double tube configuration is used when the rotational force of the rotation device 50 is transmitted to the high-pressure injection nozzle 47 using air as power, and the single tube configuration is used when the high-pressure injection nozzle 47 is rotated by water pressure.

[0041] In the illustrated example, the rotation device 50 is supported by the inner tube feed device 65, and as the inner tube feed device 65 moves along the guide rod 60 toward the chamber 10 in the X2 direction, one end 41 of the inner tube 40 and the other end 32 of the outer tube 30 around it are both pushed toward the chamber 10, and both are moved toward the chamber 10. In other words, the inner tube feed device 65 is a device that feeds not only the inner tube 40 but also the outer tube 30 toward the chamber 10. During this movement, the rotation device 50 is driven, so that the inner tube 40 moves in the X2 direction toward the chamber 10 while rotating in the X3 direction. Although not illustrated, instead of the illustrated example, the inner tube feed device 65 may directly grip the inner tube 40 and feed it out.

[0042] Here, since the pressure inside the chamber 10 is several atmospheres and the pressure inside the machine interior 15 is about 1 atmosphere, the inner pipe 40 and the outer pipe 30, which partially protrude into the chamber 10, are pushed into the machine interior 15 due to the pressure difference between the chamber 10 and the machine interior 15, and may retract toward the machine interior 15 (buckling). As shown in the illustrated example, the rotation device 50, to which one end 41 of the inner pipe 40 is attached, is supported by an inner pipe feed device 65, which is slidably attached to a guide rod 60 connected to the partition wall 12, and the guide rod 60 and the inner pipe feed device 65 also function as a buckling prevention means for preventing buckling of the inner pipe 40 and the outer pipe 30.

[0043] A high-pressure water supply device 55 is attached below the rotation device 50, and the high-pressure water supply device 55 is connected to the hollow inside of the inner pipe 40. One end 55a of the high-pressure water supply device 55 is adapted to be attached to the end of a water supply hose or water supply pipe (not shown). With the above configuration, the obstacle crushing device 100 is formed.

[0044] As shown in Figure 2, the inner tube feeding device 65 moves along the guide rod 60 in the X2 direction toward the chamber 10, moving the inner tube 40 and the outer tube 30 until one end 47a (tip) of the high-pressure injection nozzle 47 abuts against the boulder G inside the chamber 10.

[0045] 3, the rotation device 50 is driven to rotate the inner tube 40 around its axis in the X3 direction, and the inner tube feed device 65 is driven to move it further in the X4 direction toward the chamber 10. This rotation of the inner tube 40 also rotates the high-pressure injection nozzle 47 attached to the tip of the inner tube 40 in the X3 direction.

[0046] At this time, high-pressure water is supplied in the Y1 direction through a hose or the like (not shown) attached to one end 55a of the high-pressure water supply device 55, and the high-pressure water is supplied into the inside of the inner pipe 40 through the high-pressure water supply device 55. The high-pressure water that flows inside the inner pipe 40 in the Y2 direction toward the chamber 10 is then sprayed at high pressure sideways in the Y3 direction from the wall surface of the rotating high-pressure spray nozzle 47.

[0047] In this way, by forcing the high-pressure jet nozzle 47 in a rotating position against the boulder G and jetting high-pressure water laterally from the high-pressure jet nozzle 47, a bottomed hole H is formed inside the boulder G.

[0048] When forming this bottomed hole H, the inner tube 40 and the high-pressure injection nozzle 47 at its tip are fed at a constant speed by the inner tube feeding device 65, thereby forming a bottomed hole H with a hole diameter that is as uniform as possible and with as little unevenness as possible on the hole wall.

[0049] As shown in FIG. 3, in addition to the inner pipe 40 and the high-pressure injection nozzle 47 in front of it, a packer 49 attached around the protruding region 44 of the inner pipe 40 is inserted into the bottomed hole H.

[0050] After a bottomed hole H of a predetermined length is formed in the boulder G and the packer 49 has been inserted into the bottomed hole H, as shown in Figure 4, the rotation device 50 is removed from one end 41 of the inner pipe 40, the outer pipe feeding device 70 is attached to the other end 32 of the outer pipe 30, and the outer pipe 30 is moved in the direction X5 toward the chamber 10 relative to the inner pipe 40, so that one end 31 of the outer pipe 30 pushes in the packer 49, and the pushed-in packer 49 expands sideways in the direction X6. By expanding sideways in this way, the packer 49 comes into firm contact with the hole wall of the bottomed hole H, and an airtight space K is formed in the area forward of the packer 49 between the joint pipe 45 and the high-pressure injection nozzle 47 and the wall of the bottomed hole H.

[0051] Here, the outer tube feeding device 70 includes a pusher plate 72 with a through hole 72a and a plurality of bolts 75. With the inner tube 40 inserted through the through hole 72a, the other end 32 of the outer tube 30 is brought into contact with the pusher plate 72, and each bolt 75 is screwed into a corresponding bolt hole 22a provided in the flange 22 at the end of the insertion tube 20.

[0052] By rotating multiple bolts 75 at the same rate, the pusher plate 72 is slowly moved in the X5 direction toward the chamber 10, and the other end 32 of the outer tube 30 is pushed toward the chamber 10 by the moving pusher plate 72.

[0053] Here, the outer tube feeding device may be a jack or the like other than the illustrated embodiment, and the other end 32 of the outer tube 30 can be pushed in by the jack.

[0054] Furthermore, even in the state shown in FIG. 4, a pushing force toward the inside of the device 15 is acting on the inner tube 40, etc. due to the pressure difference between the chamber 10 and the inside of the device 15, so it is preferable to provide a buckling prevention means (not shown) for the inner tube 40, etc.

[0055] The packers 49 are made of rubber, and preferably made of nitrile rubber. By making the packers 49 from nitrile rubber, it is possible to impart appropriate flexibility and hardness to the packers 49, which makes it easier for the inflated packers 49 to adhere closely to the uneven hole walls and form the sealed space K. As will be described later, even after the sealed space K has been pressurized, the hard packers 49 can maintain the sealed space K against the pressure, and the pressure buildup can introduce cracks C into the boulders G, enabling them to be crushed smoothly (see Figure 5).

[0056] After forming a sealed space K between the joint pipe 45 and the high-pressure injection nozzle 47 and the wall surface of the bottomed hole H, as shown in Figure 5, a high-pressure water supply device (not shown) is attached to one end 41 of the inner pipe 40, high-pressure water is supplied into the hollow inside the inner pipe 40 in the Y1 direction, and high-pressure water is injected into the sealed space K from the high-pressure injection nozzle 47 inside the sealed space K, and the pressure inside the sealed space K is accumulated by the injection of high-pressure water.

[0057] As pressure builds up inside the sealed space K, cracks C form in the boulder G from the side of the bottomed hole H to the inside, and the formation of multiple cracks C causes the boulder G to fracture.

[0058] According to the obstacle breaking device 100 shown in the figure and the obstacle breaking method using this device, even if an obstacle such as a large boulder G is taken into the chamber 10, the obstacle can be quickly broken down into a size that can be taken in by the screw conveyor at the back of the chamber 10. This allows the shield tunneling machine to continue excavating, preventing problems such as the suspension of shield tunnel construction and the extension of the construction period due to the intake of unexpected boulders.

[0059] Furthermore, the obstacle breaking device 100 shown in the figure is not a large-scale device, so it is easy to handle and can be easily installed even in a small internal space, making it applicable to shield tunneling machines with a variety of internal dimensions.

[0060] Furthermore, since the device is configured to insert the outer pipe 30 and inner pipe 40 into the chamber 10 through a small-diameter insertion hole 13, for example, of about 2 to 3 inches, opened in the partition wall 12, obstacles G inside the chamber 10 can be smoothly crushed without causing any damage to the shield tunneling machine.

[0061] [Demonstration experiment] Next, a demonstration experiment conducted by the present inventors will be described with reference to Figures 6 to 9. Here, Figure 6 is a diagram showing the experimental equipment used in the demonstration experiment, and Figure 7 is a photograph of granite, which is the test specimen to be crushed in the demonstration experiment.

[0062] This demonstration experiment used the experimental equipment shown in Figure 6, and involved applying a reaction force from a steel plate that acted as a partition wall inside the shield tunneling machine, and drilling holes with an ultra-high pressure jet.

[0063] The boulder used as the test specimen shown in Figure 7 is a granite rock with a side length of approximately 70 cm (uniaxial compressive strength: 154 N / mm 2 ) was used.

[0064] In addition, the packers used to store water pressure within the boulders must be durable and able to conform to the unevenness of the hole wall caused by jet drilling, so three types of materials were prepared: nitrile rubber, crude rubber, and silicone rubber.

[0065] The drilling was carried out by spraying ultra-high pressure water at 250 MPa and 40 L / min from a rotating nozzle that rotated by air.

[0066] Here, the holes were drilled using two methods: manual feed (feeding at a variable speed) and mechanical feed (feeding at a constant speed). When the speed was variable (manual feed), the hole diameter varied and the hole wall was very uneven, as shown in Figure 8A, making it impossible to seal with a packer (a situation in which an airtight space could not be formed).

[0067] On the other hand, when drilling was performed using a guide rod equipped with an automatic mechanical feeder that allowed the rod to be fed at a constant speed (4 mm / sec), the hole diameter became almost uniform, the irregularities on the hole wall became smaller, and the hole could be sealed with a packer, as shown in Figure 8B.

[0068] This demonstrates that when a high-pressure jet nozzle is sent into boulders or the like to drill a bottomed hole, it is desirable to mechanically send the high-pressure jet nozzle out at a constant speed.

[0069] After drilling, the packer was pushed toward the tip using an outer tube, causing it to expand circumferentially, and pressure was then built up in the closed space created in the bottomed hole by drilling using an ultra-high pressure jet to attempt to crush the gravel.

[0070] In the cases where crude rubber and silicone packers were used, the packers adhered well to the hole walls, but they could not withstand the internal pressure and were unable to build up pressure in the sealed space.In contrast, in the case where nitrile rubber packers were used, the nitrile rubber had the appropriate flexibility and hardness, so the built-up state was able to be maintained, and cracks appeared in various places in the boulders immediately after pressure was built up, leading to the fracture of the test specimen, as shown in Figure 9.

[0071] This demonstrates that nitrile rubber is an ideal material for packers used to form sealed spaces, as it has flexibility that allows it to fit into and adhere to the irregularities in the hole wall, and hardness that allows it to withstand pressure buildup.

[0072] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0073] 10: Chamber 12: Bulkhead 12a: Back 13:Through hole 15:In the cabin 20: Insertion tube 20a: one end 20b: other end 22: Flange 22a: Bolt hole 24: Opening and closing valve 28: Prepender 30:Outer tube 31: One end (tip) 32: Other end 40: Inner tube 41: One end 44: Projection area 45: Joint pipe 47: High-pressure spray nozzle 47a: one end 49: Packer 49a: one end 50: Rotating device 55: High-pressure water supply device 60: Guide rod 61: One end 62: Support 65: Internal tube feeding device 67: Laura 70: Outer tube feeding device 72: Push-in plate 72a: Through hole 75: Bolt 100: Obstacle Breaker G: Boulder (obstacle) H: Bottom hole K: Closed space C: Crack

Claims

1. An obstacle breaking device for a shield tunneling machine, the obstacle breaking device comprising: a main body; a cutter head that rotates forward in the excavation direction of the main body; and a partition wall that forms a chamber together with the cutter head inside the main body, the obstacle breaking device breaking up an obstacle that has been taken into the chamber, an outer tube extending into the chamber through a through hole formed in the partition wall; an inner tube that is inserted into the outer tube, a portion of which protrudes from a tip of the outer tube, and is equipped with a high-pressure injection nozzle; a rotating device that rotates the inner tube; a packer attached to a protruding region around the inner pipe that protrudes from the tip of the outer pipe; an obstacle crushing device characterized in that the packer, which is disposed inside a bottomed hole formed by drilling the obstacle with a high-pressure jet from the high-pressure jet nozzle rotated by the rotating device, expands when pushed by the outer pipe, and pressure in the sealed space formed between the bottomed hole and the inner pipe is accumulated by the high-pressure jet from the high-pressure jet nozzle into the sealed space.

2. 2. The obstacle breaking device according to claim 1, wherein an insertion pipe including an opening / closing valve is attached to a position on the back surface of the partition corresponding to the insertion hole, and the outer pipe and the inner pipe inserted into the insertion pipe extend into the chamber through the insertion hole with the opening / closing valve in an open position.

3. An obstacle breaking device as described in claim 2, characterized in that a pre-bender is attached to the end of the insertion tube, the outer tube is inserted into the pre-bender while being sealed between the pre-bender and the insertion tube, and the insertion tube and the opening / closing valve.

4. A guide rod is attached to the back surface of the partition or the insertion tube, an inner tube feeding device that feeds at least the inner tube is attached to the guide rod so as to be slidable; 4. The obstacle breaking device according to claim 3, wherein the inner tube feeding device slides at a constant speed to feed out the inner tube.

5. An outer tube feeding device is attached to the end of the insertion tube, 5. An obstacle breaking device according to claim 4, wherein the outer tube is fed by the outer tube feeding device.

6. 2. The obstacle breaking device according to claim 1, wherein the packers are made of nitrile rubber.

7. 1. A method for crushing an obstacle taken into a chamber in a shield tunneling machine comprising: a main body; a cutter head that rotates forward in the excavation direction of the main body; and a partition wall that forms a chamber together with the cutter head inside the main body, the method comprising: an inner pipe having a high-pressure injection nozzle at its tip is inserted into the outer pipe, a portion of the inner pipe is protruded from the tip of the outer pipe, a packer is attached to the periphery of the inner pipe in a protruding region protruding from the tip of the outer pipe, and the outer pipe and the inner pipe are extended into the chamber through an insertion hole opened in the partition wall; The inner tube is rotated, and a bottomed hole is drilled in the obstacle by high-pressure jet from the rotating high-pressure jet nozzle. a packer disposed inside the bottomed hole, the packer pushed in and inflated by the outer pipe to form an enclosed space between the bottomed hole and the inner pipe, and high-pressure injection from the high-pressure injection nozzle into the enclosed space causes pressure to build up in the enclosed space, thereby crushing the obstacle.

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