Shaft construction apparatus and shaft construction method

Abstract

To provide a shaft construction device and a shaft construction method capable of ensuring safety inside a shaft even if excavation at a hole bottom is interrupted due to an obstacle, for example.SOLUTION: A shaft construction device that constructs a shaft underground by assembling annular liner plates 20 in the height direction comprises a cylindrical cutting edge 51 having an inner diameter larger than the outer diameter of the liner plate 20 and extending downward, an excavating part 53 for excavating the hole bottom 12 inside the cutting edge 51, a jack 56 that presses the cutting edge 51 downward using the existing liner plate 20 as a reaction force, and an inner cylindrical part 57 that is arranged inside the cutting edge 51, has a cylindrical shape with an inner diameter larger than the outer diameter of the liner plate 20, and is fixed to the jack 56 so as to be movable relative to the cutting edge 51.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a shaft construction device and a shaft construction method for constructing a shaft by assembling an annular liner plate in the height direction in the ground.

Background Art

[0002] For example, there is a deep foundation construction method for constructing a shaft by assembling an annular liner plate in the height direction in the ground. Specifically, it is a construction method in which the bottom of the hole is excavated and the excavated hole wall is protected with an annular liner plate up to a predetermined depth, and the construction method described in Patent Document 1 is also one of them.

[0003] In this Patent Document 1, an excavation device for excavating the bottom of the hole is arranged below the annular liner plate assembled in the height direction, and a support device for supporting the excavation device is pressed against the hole wall to secure the support reaction force of the excavation device.

[0004] Furthermore, when the excavation to the depth corresponding to one ring is completed, in Patent Document 1, a workbench arranged above the excavation device is lowered by the support device, and a worker on the workbench assembles a new liner plate to the lowermost liner plate, and this is repeated up to a predetermined depth to construct a shaft of the predetermined depth.

[0005] By the way, in the deep foundation construction method, for example, when the excavation of the bottom of the hole is hindered by an obstacle such as rock, it is necessary to interrupt the excavation of the bottom of the hole and remove the obstacle. At this time, since the excavation of the bottom of the hole is interrupted, a part of the excavated hole wall may not be protected by the liner plate.

[0006] For example, in the case of Patent Document 1, when the excavation of the bottom of the hole is interrupted to remove the obstacle, the hole wall is exposed between the existing assembled liner plate and the support device, and the obstacle at the bottom of the hole is removed. Then, in Patent Document 1, when the hole wall collapses due to an unintended vibration or the like, there is a risk that earth and sand may flow into the pit. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 9-165990 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In view of the above-mentioned problems, the present invention aims to provide a shaft construction device and a shaft construction method that can ensure safety inside the shaft even if excavation of the bottom of the hole is interrupted by, for example, an obstruction. [Means for solving the problem]

[0009] This invention relates to a shaft construction device for constructing a shaft underground by assembling annular liner plates in the height direction, characterized in that it is provided with a cylindrical cutting edge that extends downward and has an inner dimension larger than the outer dimension of the liner plate, an excavation section for excavating the bottom of the hole inside the cutting edge, an extension mechanism that uses the existing assembled liner plate as a reaction force to press the cutting edge downward, and an inner cylindrical section that is positioned inside the cutting edge, has an inner dimension larger than the outer dimension of the liner plate, and is fixed to the extension mechanism so as to be movable relative to the cutting edge.

[0010] Furthermore, this invention relates to a method for constructing a shaft underground by assembling annular liner plates in the height direction, wherein the method involves repeatedly performing an excavation step in which an excavation section excavates the bottom of a hole inside a cylindrical cutting edge that extends downward and has an inner dimension larger than the outer dimension of the liner plate; an extension step in which an extension mechanism pushes the cutting edge downward using an existing assembled liner plate as a reaction force to lower the cutting edge; and an assembly step in which, when the cutting edge has been lowered by at least one stage of the liner plate, the liner plate is assembled to the lower end of the lowest assembled liner plate, and in the extension step, an inner cylindrical portion, which is positioned inside the cutting edge and has an inner dimension larger than the outer dimension of the liner plate, and is fixed to the extension mechanism so as to be movable relative to the cutting edge, protrudes upward from the upper end of the cutting edge as the cutting edge is lowered.

[0011] The above-mentioned external and internal dimensions refer to the outer diameter and inner diameter in the case of a roughly circular cylindrical shape, and the distance between opposing outer surfaces and the distance between inner surfaces in the case of a roughly rectangular cylindrical shape. The term "tubular" as used above refers to cylindrical shapes that are roughly circular, roughly rectangular, etc. The downward movement of the blade opening, as described above, refers to sinking due to its own weight, or to downward movement caused by applying a downward load in addition to sinking due to its own weight; this is also called subsidence.

[0012] According to this invention, by having an inner cylindrical portion fixed to the telescopic mechanism so as to be movable relative to the cutting edge and protruding upward from the upper end of the cutting edge, safety in the tunnel can be ensured even if excavation of the bottom of the hole is interrupted by an obstacle, for example.

[0013] Specifically, since the inner cylinder is fixed to the telescopic mechanism so as to be movable relative to the blade opening, the inner cylinder can protrude above the upper end of the blade opening as the telescopic mechanism extends and the blade opening descends.

[0014] Furthermore, because the internal dimensions of the inner cylinder, which is positioned inside the cutting edge, are larger than the external dimensions of the liner plate, the portion of the inner cylinder that protrudes from the upper end of the cutting edge faces the wall of the hole. Therefore, the shaft construction device and shaft construction method allow the inner cylindrical section to function as a temporary earth retaining structure positioned on the outer surface side of the assembled liner plate.

[0015] As a result, the shaft construction device and shaft construction method can prevent soil and debris that have collapsed from the borehole wall from flowing into the inside of the cutting edge through the gap between the upper end of the cutting edge and the lower end of the assembled liner plate, thanks to the inner cylindrical section. Therefore, the shaft construction device and shaft construction method can ensure safety inside the shaft without the need to install separate earth retaining structures, even if excavation of the bottom of the shaft is interrupted, for example, by an obstruction.

[0016] In addition, since it eliminates the need to separately install earth retaining structures inside the shaft after interrupting excavation at the bottom of the hole, the shaft construction device and shaft construction method enable the safe and efficient removal of obstacles.

[0017] In one aspect of this invention, the telescopic mechanism comprises a telescopic main body that extends and retracts in the height direction, and a contact portion provided at the tip of the telescopic main body that abuts against the lower end of the assembled liner plate, wherein the telescopic main body is fixed to the cutting edge and the inner cylinder is fixed to the contact portion. With this configuration, the blade opening and inner cylinder are fixed to the telescopic mechanism, which consists of a telescopic main body and a contact part. This allows for the downward movement of the blade opening and the protrusion of the inner cylinder to be achieved with a simple structure.

[0018] Furthermore, since the inner cylinder is fixed to the contact portion of the telescopic mechanism that contacts the assembled liner plate, the inner cylinder can be positioned at the desired location as if it were fixed to the assembled liner plate. This allows the shaft construction device to better prevent the exposure of the borehole wall as the cutting edge descends, and to withstand the earth pressure from soil that collapses from the borehole wall.

[0019] As an aspect of the present invention, the outer peripheral surface of the inner cylindrical portion may be configured to face at least the upper portion of the inner peripheral surface of the cutting edge. According to this configuration, in a state where the expansion and contraction mechanism portion is extended, it is possible to prevent the hole wall from being exposed from between the upper end of the cutting edge and the lower end of the inner cylindrical portion.

[0020] Thereby, the shaft sinking construction device can prevent the earth and sand that has fallen from the hole wall from overcoming the upper end of the cutting edge and flowing into the inside of the cutting edge, so that the safety inside the shaft can be further improved.

[0021] As an aspect of the present invention, the upper end of the inner cylindrical portion may be configured to abut or be close to the backfill material filled between the outer surface of the assembled liner plate one step above the lowermost step and the hole wall. According to this configuration, it is possible to suppress the exposure of the hole wall from between the upper end of the inner cylindrical portion and the lower end of the backfill material.

[0022] Thereby, the shaft sinking construction device can suppress the earth and sand that has fallen from the hole wall from overcoming the upper end of the inner cylindrical portion and flowing into the inside of the cutting edge, so that the safety inside the shaft can be further improved.

[0023] As an aspect of the present invention, the length of the inner cylindrical portion in the height direction may be longer than the length of one of the liner plates in the height direction. According to this configuration, even if the cutting edge descends below the lower end of the lowermost liner plate, it is possible to prevent a gap from occurring between the lower end of the inner cylindrical portion and the upper end of the cutting edge.

[0024] Therefore, the shaft sinking construction device can surely prevent the hole wall from being exposed above the cutting edge by the inner cylindrical portion. Thereby, the shaft sinking construction device can prevent the earth and sand that has fallen from the hole wall from overcoming the upper end of the cutting edge and flowing into the inside of the cutting edge, so that the safety inside the shaft can be further improved.

[0025] In another aspect of this invention, the telescopic mechanism may be provided in multiple locations at predetermined intervals in the circumferential direction of the cutting edge. This configuration allows the inner cylinder to be stably supported inside the blade opening, and also allows the inner cylinder to move relative to the blade opening in a balanced manner. This allows the shaft construction device to stably protrude the inner cylindrical section above the cutting edge.

[0026] In another aspect of this invention, a work platform supported by the cutting edge may be provided below the inner cylindrical portion. In this configuration, the outer surface of the cutting edge and the outer surface of the inner cylinder face the hole wall, and the work platform is located above the bottom of the hole.

[0027] Therefore, the shaft construction device can prevent soil and debris from falling to the bottom of the shaft through the cutting edge, inner cylinder, and work platform. This allows the shaft construction device to support the safe removal of obstacles by workers.

[0028] In another aspect of this invention, a blocking member may be detachably provided to block the space between the lower end of the existing assembled liner plate and the hole wall. With this configuration, when the inner cylindrical portion is housed inside the cutting edge to fill the gap between the outer surface of the assembled liner plate and the hole wall with backfill material, the opening that is created between the assembled liner plate and the cutting edge can be closed by the blocking member.

[0029] Therefore, for example, the blocking member can prevent soil and sand that have collapsed from the hole wall before the backfill material is filled from flowing into the inside of the cutting edge through the opening between the assembled liner plate and the cutting edge. Therefore, the shaft construction device can ensure safety inside the shaft not only when excavation of the bottom of the hole is interrupted, but also before backfilling is completed. [Effects of the Invention]

[0030] The present invention provides a shaft construction device and a shaft construction method that can ensure safety inside the shaft even if excavation of the bottom of the hole is interrupted, for example, by an obstruction. [Brief explanation of the drawing]

[0031] [Figure 1] A schematic cross-sectional perspective view of a mechanical deep foundation construction method. [Figure 2] Schematic cross-sectional view of the mechanical deep foundation construction method in the direction of arrow AA in Figure 1. [Figure 3] A bottom view showing the bottom of the excavation unit. [Figure 4] An explanatory diagram showing an enlarged cross-sectional view of the backfill area. [Figure 5] A schematic diagram showing the configuration of the control unit. [Figure 6] A flowchart illustrating the process of the mechanical deep foundation construction method. [Figure 7] A flowchart illustrating the process of the mechanical deep foundation construction method. [Figure 8] An explanatory diagram showing a schematic cross-section of the mechanical deep foundation construction method. [Figure 9] An explanatory diagram showing a schematic cross-section of the mechanical deep foundation construction method. [Figure 10] An explanatory diagram showing a schematic cross-section of the mechanical deep foundation construction method. [Figure 11] An explanatory diagram showing a schematic cross-section of the mechanical deep foundation construction method. [Figure 12] An explanatory diagram showing a schematic cross-section of the mechanical deep foundation construction method. [Figure 13] An explanatory diagram showing a schematic cross-section of the mechanical deep foundation construction method. [Modes for carrying out the invention]

[0032] One embodiment of a mechanical deep foundation construction method using an excavation unit 50 will be described below with reference to the drawings. Figure 1 shows a schematic cross-sectional perspective view of the mechanical deep foundation construction method, Figure 2 shows a schematic cross-sectional view of the mechanical deep foundation construction method, Figure 3 shows a bottom view of the excavation unit 50, Figure 4 shows an explanatory diagram of the backfill area using an enlarged cross-sectional view, and Figure 5 shows a schematic configuration diagram of the control unit 60.

[0033] Furthermore, Figure 4(a) shows an enlarged cross-sectional view of the bottom ring 20A with the blocking member 58 attached, and Figure 4(b) shows an enlarged cross-sectional view of the bottom ring 20A with the backfill material 30 filled between it and the hole wall 11a. Furthermore, the upper part of Figure 1 is considered to be above the excavation unit 50, and the lower part of Figure 1 is considered to be below the excavation unit 50.

[0034] Furthermore, in Figure 1, to clarify the illustration, the front side of the liner plate 20 is shown in a transparent state, and the illustration of the backfill material 30 is omitted. In addition, in Figure 1, the front side of the cutting edge 51 and inner cylindrical portion 57 of the excavation unit 50 are shown in a transparent state, and the work platform 54 is shown with a dashed line.

[0035] First, as shown in Figures 1 and 2, the shaft constructed using the mechanical deep foundation method is constructed by sequentially assembling ring-shaped liner plates 20, each having an outer diameter slightly smaller than the excavated hole 11, downwards inside the excavated hole 11 created by drilling the ground 10, and filling the space between the liner plates 20 and the hole wall 11a of the excavated hole 11 with backfill material 30.

[0036] Here, the liner plate 20 will be described in more detail. As shown in Figures 1 and 2, the liner plate 20 is constructed by assembling multiple arc-shaped liner plate sections (not shown in numerals), each of which has assembly flanges on all four sides of a corrugated thin steel sheet, in a ring shape.

[0037] Furthermore, the liner plates 20 are connected downwards within the borehole 11 by being sequentially assembled to the lower side of the lowest layer of the existing liner plates 20 as the excavation of the borehole 11 progresses.

[0038] In this case, the lowest liner plate 20 of the existing liner plates 20 and the newly assembled liner plate 20 are assembled with a circumferential offset so that the circumferential connection positions of the liner plate sections do not coincide in the vertical direction.

[0039] Furthermore, the liner plate 20 is provided with a filling port 201 for filling with backing material 30, which penetrates the corrugated thin steel plate (see Figure 4). In addition, reinforcing ribs (not shown) are provided vertically in the circumferential center of the liner plate section to resist the reaction force of the jack 56, which will be described later.

[0040] In this embodiment, of the existing liner plates 20 that are assembled sequentially downwards, the uppermost liner plate 20 that protrudes slightly upward from the ground surface 10a is referred to as the first ring 21, the second liner plate 20 assembled below the first ring 21 is referred to as the second ring 22, the third liner plate 20 is referred to as the third ring 23, the nth liner plate 20 is referred to as the nth ring 2n, and the lowest liner plate 20 is referred to as the lowest ring 20A (see Figures 1 and 2).

[0041] A shaft construction device for constructing such a shaft consists of an excavation unit 50 (see Figure 1) for excavating the ground 10 and a control unit 60 (see Figure 5) for controlling the operation of the excavation unit 50.

[0042] As shown in Figures 1 and 2, the excavation unit 50 of the shaft construction device comprises a cylindrical cutting edge 51 extending in the vertical direction, a support frame 52 positioned inside the cutting edge 51, an excavation section 53 positioned below the support frame 52, and a work platform 54 positioned above the support frame 52.

[0043] Furthermore, as shown in Figures 1 and 2, the excavation unit 50 includes a soil removal unit 55 and four jacks 56 arranged to straddle the work platform 54 in the vertical direction, and an inner cylindrical section 57 positioned above the work platform 54. The excavation unit 50 also includes a blocking member 58 (see Figure 4), which will be described later, as a component for filling the backfill material 30.

[0044] More specifically, the cutting edge 51 of the drilling unit 50 is a cylindrical steel body having a predetermined thickness, as shown in Figures 1 and 2, and is formed with an outer diameter slightly larger than the ring-shaped liner plate 20. The cutting edge 51 is formed to a height of approximately five rings of the liner plate 20.

[0045] The cutting edge 51 is connected to the jack 56 such that its upper end is positioned below the lower end of the lowest ring 20A on the existing liner plate 20 when the blocking member 58 (described later) is attached to the existing liner plate 20 (see Figure 10(a)) or when the jack 56 (described later) is extended (see Figure 13).

[0046] Furthermore, as shown in Figures 1 and 2, the support frame 52 of the drilling unit 50 is attached to the inner surface 51a of the cutting edge 51 at a position slightly below the height of one ring of the liner plate 20 from the upper end of the cutting edge 51.

[0047] As shown in Figure 3, the support frame 52 consists of a central support portion 521 positioned in the center of the bottom view of the cutting edge 51, and three beam-shaped support portions 522 extending in three directions from the central support portion 521 toward the inner surface 51a of the cutting edge.

[0048] Specifically, the central support portion 521 is roughly circular in shape when viewed from the bottom and is formed to have a diameter about one-third that of the cutting edge 51. The excavation portion 53 is rotatably connected to the lower surface of this central support portion 521. On the other hand, the beam-shaped support portion 522 is a columnar body that extends toward the cutting edge 51 from positions that are equally spaced in the circumferential direction on the central support portion 521, and its end is attached to the inner surface 51a of the cutting edge.

[0049] Furthermore, as shown in Figures 2 and 3, the drilling section 53 of the drilling unit 50 is rotatably suspended and supported on the lower surface of the central support section 521 of the support frame 52. This drilling section 53 is configured to drill the bottom of the hole 12 inside the cutting edge 51 while suspended and supported by the support frame 52.

[0050] Specifically, as shown in Figure 2, the excavation unit 53 includes an excavation unit body 531 that is rotatably suspended and supported below the central support unit 521, a first arm 532 that is pivotable relative to the excavation unit body 531, a second arm 533 that is pivotable relative to the first arm 532, and an excavation bucket 534 that is pivotably provided at the tip of the second arm 533.

[0051] Based on control signals from a control unit 60 (described later), the drilling unit 53 rotates the drilling unit body 531 relative to the central support 521, while the first arm 532, the second arm 533, and the drilling bucket 534 pivot, thereby drilling the entire bottom of the hole 12 inside the cutting edge 51.

[0052] Furthermore, the working platform 54 of the excavation unit 50 is a floor surface where the worker M can assemble the liner plate 20 and perform other tasks inside the cutting edge 51, as shown in Figure 2. This working platform 54 is made up of a plate material that is roughly circular in plan view and is placed on the upper surface of the support frame 52, as shown in Figures 1 and 2.

[0053] Furthermore, as shown in Figures 1 and 3, the work platform 54 has openings formed by cutting out the outer edge, through which the soil removal bucket 552 of the soil removal unit 55 (described later) passes. Specifically, the through hole 54a is formed by cutting out a portion of the work platform 54 located between the beam-shaped support portions 522 of adjacent support frames 52 in the circumferential direction of the cutting edge 51, extending radially from the outer edge towards the center.

[0054] Furthermore, the soil removal unit 55 of the excavation unit 50 is a unit that transports the excavated soil, which has been excavated from the bottom of the hole 12 by the excavation section 53, to the outside through the through hole 54a of the work platform 54. As shown in Figure 2, this soil removal unit 55 consists of a soil removal rail 551 that extends upward from the bottom of the blade opening 51 to the top of the first ring 21, and a soil removal bucket 552 that moves up and down along the soil removal rail 551.

[0055] Specifically, the soil removal rail 551 is positioned to penetrate the through hole 54a of the work platform 54 and is fixed to the inner surface 51a of the cutting edge 51 and the liner plate 20, which are adjacent to each other in the horizontal direction. Furthermore, the soil removal rail 551 is configured to be extendable as the excavation of the hole bottom 12 progresses.

[0056] Meanwhile, the excavation bucket 552 is the part into which the excavated soil from the bottom of the hole 12 is loaded, and is connected to the excavation rail 551 so as to be movable relative to it. This excavation bucket 552 is raised and lowered by a lifting winch (not shown) installed on the ground.

[0057] Furthermore, the four jacks 56 of the excavation unit 50 are extension and retraction mechanisms that use the existing liner plate 20 as a reaction force to press the cutting edge 51 downwards, and are composed of, for example, hydraulic jacks that can extend and retract in the vertical direction.

[0058] As shown in Figure 3, these four jacks 56 are positioned between adjacent beam-shaped support portions 522 of the support frame 52 in the circumferential direction of the cutting edge 51, and are arranged at equal intervals in the circumferential direction of the cutting edge 51. Such a jack 56 is connected to a hydraulic pump 59 (see Figure 5) that operates based on a control signal from a control unit 60, which will be described later, and comprises a main body 561 that expands and contracts by the operating pressure of the hydraulic pump 59, and a spreader 562 provided at the tip of the main body 561.

[0059] Specifically, as shown in Figure 2, the main body 561 of the jack 56 consists of a cylinder 561a attached to the inner surface 51a of the cutting edge 51 at a position above the work platform 54, and a piston rod 561b that can extend and retract above the cylinder 561a. On the other hand, as shown in Figure 3, the spreader 562 of the jack 56 is formed in a roughly arc shape when viewed from the bottom, so as to be able to contact the lowest ring 20A, and its approximate center in the circumferential direction is connected to the tip of the piston rod 561b.

[0060] Furthermore, as shown in Figures 1 and 2, the inner cylindrical portion 57 of the excavation unit 50 is a cylindrical body made of steel of the same material as the cutting edge 51 and having the same thickness as the cutting edge 51, and is positioned to be housed above the work platform 54 inside the cutting edge 51. This inner cylindrical portion 57 is fixed to the jack 56 so as to be movable relative to the cutting edge 51, which is fixed to the cylinder 561a, in the direction opposite to the direction of movement of the cutting edge 51.

[0061] Specifically, as shown in Figure 2, the inner cylindrical portion 57 is formed in a cylindrical shape that extends vertically, having an outer diameter slightly larger than the inner diameter of the cutting edge 51 and an inner diameter slightly larger than the outer diameter of the existing liner plate 20.

[0062] Furthermore, the inner cylindrical portion 57 is longer than the height of one ring of the liner plate 20, and is formed with a vertical length such that the outer surface near the lower end can overlap with the inner surface near the upper end of the cutting edge 51 when it is in its lowest relative position.

[0063] The inner surface of this inner cylindrical portion 57 is fixed to four jacks 56 arranged along the circumferential direction. More specifically, the inner circumferential surface of the inner cylindrical portion 57, located one ring length below the upper end of the liner plate 20, is fixed to the spreader 562 of the jack 56 (see Figure 11). The spreader 562 is fixed to the inner circumferential surface of the inner cylindrical portion 57 at a position one ring length below the upper end of the liner plate 20, with its upper surface aligned with the liner plate 20.

[0064] Therefore, when the spreader 562 is in contact with the lower end of the bottom ring 20A, the upper end of the inner cylindrical portion 57 is in contact with or close to the lower end of the backfill material 30 that is filled between the liner plate 20 one level above the bottom ring 20A and the hole wall 11a.

[0065] Furthermore, as shown in Figure 4, the aforementioned blocking member 58 is a member that closes the opening created between the lower end of the lowest ring 20A and the hole wall 11a of the excavated hole 11, and is configured to be detachably attached to the lower flange of the lowest ring 20A. The blocking member 58 is fixed to the lower flange of the lowest ring 20A by clamps C arranged at predetermined intervals in the circumferential direction.

[0066] Specifically, the blocking member 58 comprises a gap-filling ring 581, which is an annular flat plate having an outer diameter larger than the outer diameter of the liner plate 20, and an annular gap-filling tip portion 582 that is attached to the outer peripheral edge of the gap-filling ring 581 and abuts against the hole wall 11a.

[0067] Furthermore, as shown in Figure 5, the control unit 60 of the shaft construction device consists of a camera 61, a sensor 62, a display unit 63, an operation unit 64, a storage unit 65, and a control unit 66 that controls the operation of these, and has the function of detecting the excavation status of the hole bottom 12 inside the cutting edge 51.

[0068] Furthermore, as shown in Figure 5, the control unit 60 is connected to the excavation unit 53 and the hydraulic pump 59, and has the function of receiving operations from worker M and controlling the operation of the excavation unit 53 and the hydraulic pump 59.

[0069] Furthermore, the control unit 60 is configured such that the display unit 63 and the operation unit 64 are located on the ground near the construction site, or in a management office located away from the construction site, allowing a worker M on the ground to remotely operate the excavation unit 53 and the jack 56.

[0070] Specifically, the camera 61 is composed of a CCD camera or the like, and has the function of capturing an image of the area to be captured and the function of transmitting the captured video data to the control unit 66. This camera 61 is positioned to capture the bottom of the hole 12 inside the blade opening 51. Multiple cameras 61 may be arranged, and the imaging direction may be controlled by the operation unit 64, which will be described later.

[0071] Furthermore, the sensor 62 is configured to detect the excavation status of the hole bottom 12 inside the cutting edge 51 in a non-contact manner. Furthermore, the display unit 63 is composed of a liquid crystal display or the like, and has the function of displaying the excavation status of the hole bottom 12 inside the cutting edge 51, as well as video data captured by the camera 61, based on signals from the control unit 66.

[0072] Furthermore, the control unit 64 consists of switches, a touch panel integrated with the display unit 63, and an operating lever for operating the excavation unit 53, and has the function of receiving various operations from the worker M and outputting them to the control unit 66.

[0073] Furthermore, the storage unit 65 is configured as an HDD or SSD and has the function of storing various types of information and the function of reading various types of information. This storage unit 65 stores various types of information acquired from the camera 61 and sensor 62, as well as programs that control the operation of each part.

[0074] Furthermore, the control unit 66 is composed of hardware such as a CPU and memory, and software such as a control program. This control unit 66 has processing functions related to the exchange of various signals with each component connected by wire or wireless, and functions to control the operation of each component connected by wire or wireless.

[0075] For example, the control unit 66 has processing functions related to the exchange of various signals with the camera 61 and sensor 62, various processing functions related to the calculation of the excavation status of the hole bottom 12, processing functions related to the exchange of various information with the excavation unit 53 and hydraulic pump 59, and functions to control the operation of the excavation unit 53 and hydraulic pump 59.

[0076] Next, a mechanical deep foundation construction method, which uses the excavation unit 50 with the above-described configuration to construct a predetermined shaft inside the ground 10, will be explained with reference to Figures 6 to 13. Figures 6 and 7 show flowcharts of the process in the mechanical deep foundation construction method, and Figures 8 to 13 show explanatory diagrams of the mechanical deep foundation construction method using schematic cross-sectional views. Furthermore, Figures 8 through 13 are shown in the cross-sectional view taken along the arrow BB in Figure 3 for clarity.

[0077] More specifically, Figure 8(a) shows a cross-sectional view with the mouth pipe 70 installed, Figure 8(b) shows a cross-sectional view with the excavation unit 50 and reaction frame 80 installed, Figure 8(c) shows a cross-sectional view with the cutting edge 51 submerged using the reaction frame 80 as a reaction force, and Figure 8(d) shows a cross-sectional view after excavating one ring.

[0078] Furthermore, Figure 9(a) shows a cross-sectional view with the first ring 21 installed, and Figure 9(b) shows a cross-sectional view with the cutting edge 51 submerged by one ring using the first ring 21 as a reaction force. Furthermore, Figure 10(a) shows a cross-sectional view of the backfilling process, and Figure 10(b) shows a cross-sectional view of the second ring 22 assembled after the backfilling process is completed.

[0079] Furthermore, Figure 11(a) shows a cross-sectional view of the jack 56 in contact with the second ring 22, and Figure 11(b) shows an enlarged cross-sectional view of the main part in Figure 11(a). Furthermore, Figure 12(a) shows a cross-sectional view of the state in which the cutting edge 51 descends with the second ring 22 acting as a reaction force, and Figure 12(b) shows an enlarged cross-sectional view of the main part in Figure 12(a). Furthermore, Figure 13(a) shows a cross-sectional view of the blade opening 51 after it has been submerged by one ring, and Figure 13(b) shows an enlarged cross-sectional view of the main part in Figure 13(a).

[0080] First, in order to form a shaft inside the ground 10, worker M installs the opening pipe 70 at the desired construction site, as shown in Figure 6 (step S101). Specifically, as shown in Figure 8(a), worker M installs a liner plate 71, which is slightly larger in diameter than the cutting edge 51, in a location where the ground surface 10a of the construction site has been excavated. Then, fixing concrete 72 is poured on the outer diameter of the liner plate 71 to install the opening pipe 70. Furthermore, the inner surface of the opening pipe 70 is configured to form the hole wall 11a of the excavated hole 11.

[0081] Subsequently, worker M installs the excavation unit 50 inside the opening pipe 70, as shown in Figure 6, and fixes the reaction frame 80 to the fixing concrete 72 of the opening pipe 70 (step S102).

[0082] As shown in Figure 8(b), the reaction frame 80 is constructed in a tower shape, consisting of a column section 81 whose lower end is fixed to the fixed concrete 72, a beam section 82 bridged over the upper end of the column section 81, and a jack receiving section 83 that is suspended downward from the beam section 82 and receives the reaction force of the jack 56. The reaction frame 80 is configured so that the length of the column section 81 can be changed as the cutting edge 51 descends.

[0083] Specifically, as shown in Figure 8(b), worker M positions the excavation unit 50 inside the mouth pipe 70 using heavy machinery or the like so that the inner surface of the mouth pipe 70 and the outer surface of the cutting edge 51 face each other. At this time, worker M sets the jack 56 of the excavation unit 50 to its most retracted state. Afterward, worker M assembles and fixes the reaction frame 80 to the opening pipe 70 so that the jack receiving section 83 is positioned above the jack 56.

[0084] Once the drilling unit 50 and the reaction frame 80 are set up, worker M operates the control unit 60's operating section 64 to start drilling the hole bottom 12 inside the cutting mouth 51 and to start the sinking of the cutting mouth 51 (step S103).

[0085] Specifically, based on a control signal from the control unit 66 of the control unit 60, the excavation section 53 of the excavation unit 50 excavates the bottom of the hole 12 inside the cutting edge 51, as shown in Figure 8(b). At this time, the excavated soil from the bottom of the hole 12 is loaded into the soil removal bucket 552 of the soil removal unit 55 each time excavation is performed.

[0086] Furthermore, based on a control signal from the control unit 66 of the control unit 60, the hydraulic pump 59 extends the jack 56, causing the spreader 562 of the jack 56 to contact the jack receiving portion 83 of the reaction frame 80. As the jack 56, now in contact with the reaction frame 80, extends further, it uses the reaction frame 80 as a reaction force to push the cutting edge 51 downwards, causing it to descend.

[0087] Subsequently, excavation of the hole bottom 12 continues until the soil bucket 552 is full of excavated soil (Step S104: No). When the soil bucket 552 is full of excavated soil (Step S104: Yes), worker M operates the control unit 60's control panel 64 to interrupt the excavation of the hole bottom 12 and remove the excavated soil from the soil bucket 552 out of the hole (Step S105).

[0088] Specifically, based on the control signal from the control unit 66, the excavation unit 53 pivots the second arm 533 toward the first arm 532, pivots the excavation bucket 534 toward the second arm 533 to make it more compact, and rotates the excavation unit body 531 relative to the central support 521 to move it out of the position below the through hole 54a.

[0089] Furthermore, the soil removal bucket 552 is hoisted up by a lifting winch (not shown) set on the ground and moved upward along the soil removal rail 551. At this time, the soil removal bucket 552 moves above the inner cylindrical section 57 by passing through the through hole 54a of the work platform 54, and the excavated soil is transported out of the hole.

[0090] Then, the empty soil bucket 552 is moved downward along the soil removal rail 551 using a lifting winch. As the soil bucket 552 descends along the soil removal rail 551, it passes through the through hole 54a and descends to the bottom of the hole 12. Once the soil removal unit 55 has completed, the excavation section 53 is returned to its normal excavation position and posture, and excavation of the bottom of the hole 12 is resumed.

[0091] In this manner, the bottom of the hole 12 is excavated while removing the excavated soil until the depth from the ground surface 10a to the working platform 54 of the excavation unit 50 is greater than the height of one ring of the liner plate 20 (step S106: No). If the jack 56 is fully extended while the cutting edge 51 is descending, worker M will retract the jack 56 and lower the height of the reaction frame 80, as shown in Figure 8(c), and then resume excavating the bottom of the hole 12.

[0092] Then, as shown in Figure 8(d), when the bottom of the hole 12 is excavated until the depth from the ground surface 10a to the working platform 54 of the excavation unit 50 is greater than the height of one ring of the liner plate 20 (Step S106: Yes), worker M assembles the first ring 21 (Step S107). Specifically, worker M operates the control unit 60's control panel 64 to stop the excavation unit 53 from moving and to shorten the jack 56 by the height of one ring of the liner plate 20.

[0093] Subsequently, worker M places the liner plate section between the reaction frame 80 and the jack 56, as shown in Figure 9(a), and assembles the liner plate section in a ring shape to form the first ring 21, which is the uppermost liner plate 20. In this case, since there are no existing liner plates 20 other than the first ring 21, the first ring 21 becomes the lowest ring 20A.

[0094] Once the first ring 21 is formed, worker M operates the control unit 60's operating section 64, as shown in Figure 7, to resume excavation of the hole bottom 12 and the sinking of the cutting edge 51 (step S108). At this time, the jack 56 of the excavation unit 50 pushes the cutting edge 51 downward using the first ring 21 as a reaction force, as shown in Figure 9(b), thereby lowering the cutting edge 51.

[0095] Subsequently, similar to steps S104 and S105 in Figure 6, the excavation of the hole bottom 12 continues until the soil bucket 552 is full of excavated soil (step S109: No). When the soil bucket 552 is full of excavated soil (step S109: Yes), worker M operates the control unit 60's control panel 64 to interrupt the excavation of the hole bottom 12 and discharge the excavated soil from the soil bucket 552 out of the hole (step S110).

[0096] Then, the bottom of the hole 12 is excavated while removing the excavated soil until the cutting edge 51 sinks down by the height of one ring of the liner plate 20 (step S111: No).

[0097] Then, as shown in Figure 9(b), once the cutting edge 51 has sunk to a height equivalent to one ring of the liner plate 20 (Step S111: Yes), worker M operates the control unit 60's control section 64 to stop the excavation of the hole bottom 12 and the descent of the cutting edge 51.

[0098] In this case, as shown in Figure 4(a), the upper end of the cutting edge 51 is positioned below the lower end of the first ring 21, and it has descended to a position where a gap is obtained to which the blocking member 58 can be attached.

[0099] Subsequently, worker M performs backfilling work by filling the space between the lowest ring 20A and the hole wall 11a of the excavated hole 11 with backfill material 30 (step S112). In this backfilling work, worker M first attaches the blocking member 58 to the lower flange of the lowest ring 20A with a clamp C, as shown in Figures 4(a) and 10(a) (step S113).

[0100] Specifically, as shown in Figures 4(a) and 10(a), worker M operates the operating unit 64 to separate the spreader 562 from the lowest ring 20A, and to house the inner cylindrical portion 57 inside the cutting edge 51 so that the upper end of the inner cylindrical portion 57 is positioned below the upper end of the cutting edge 51.

[0101] Subsequently, worker M attaches the blocking member 58 to the lower flange of the bottom ring 20A with clamp C, thereby closing the space between the lower end of the bottom ring 20A and the hole wall 11a of the excavated hole 11. Once the blocking member 58 is installed, worker M fills the space between the lowest ring 20A and the hole wall 11a with backfill material 30 through the filling port 201, as shown in Figures 4(a) and 4(b) (step S114).

[0102] Then, once the backfill material 30 that has been filled into the space between the bottom ring 20A and the hole wall 11a has hardened, worker M removes the blocking member 58 attached to the lower flange of the bottom ring 20A (step S115), completing the backfill work (step S112).

[0103] Once the backfilling work (step S112) is completed, worker M arranges the liner plate sections in a ring below the bottom ring 20A, as shown in Figure 10(b), to form a new liner plate 20, which is the second ring 22 (step S116). This second ring 22 becomes the bottom ring 20A of the existing liner plate 20.

[0104] Subsequently, if excavation has not been completed to a predetermined depth to which the desired shaft can be constructed (Step S117: No), worker M operates the control unit 60's operating section 64 and repeats the processes from Step S108 to Step S116 described above until the borehole 11 reaches the predetermined depth.

[0105] In this process, while the cutting edge 51 descends, the inner cylindrical portion 57 fixed to the spreader 562 does not move relative to it. Therefore, the inner cylindrical portion 57 protrudes from the upper end of the cutting edge 51, preventing the hole wall 11a of the excavated hole 11 from being exposed from the upper end of the downward-descending cutting edge 51.

[0106] Specifically, in step S108, when the spreader 562 of the jack 56 contacts the lower end of the lowest ring 20A (see Figure 11(a)), the inner cylindrical portion 57 fixed to the spreader 562 protrudes upward from the upper end of the cutting edge 51, as shown in Figure 11(b), facing the hole wall 11a, and its upper end contacts the lower surface of the backfill material 30 filled between the liner plate 20 one level above the lowest ring 20A and the hole wall 11a.

[0107] As a result, the inner cylindrical portion 57 closes the gap between the upper end of the cutting edge 51 and the backing material 30. In this case, the portion of the inner cylinder portion 57 below the upper end of the cutting edge 51 overlaps with the cutting edge 51.

[0108] When the jack 56, which is in contact with the lowest ring 20A, extends further using the lowest ring 20A as a reaction force (see Figure 12(a)), the inner cylindrical portion 57 fixed to the spreader 562 does not move, and the cutting edge 51 fixed to the cylinder 561a of the jack 56 moves downward while partially overlapping the inner cylindrical portion 57. As a result, the inner cylindrical portion 57 protrudes further upward from the upper end of the cutting edge 51, as shown in Figure 12(b).

[0109] Then, in step S111, when the cutting edge 51 sinks down by an amount equivalent to the height of one ring of the liner plate 20 (see Figure 13(a)), the lower part of the outer circumferential surface of the inner cylinder portion 57 overlaps with the upper part of the inner circumferential surface of the cutting edge 51, as shown in Figure 13(b).

[0110] As a result, the inner cylindrical portion 57 prevents the borehole wall 11a from being exposed inside the borehole 11 from the time the cutting edge 51 starts to sink after the lowest ring 20A is assembled until it has sunk by an amount equivalent to the height of one ring of the liner plate 20.

[0111] In this manner, when the excavation is completed to a predetermined depth where the desired shaft can be constructed by repeating steps S108 to S116 as described above (step S117: Yes), worker M stops excavating the bottom of the hole 12. Subsequently, worker M completes the main construction by performing post-processing work (step S118) according to the specifications required for the shaft, such as removing the support frame 52 equipped with the cutting edge 51, the excavation section 53, the work platform 54, the jack 56, and the soil removal unit 55, and spraying the bottom of the hole 12 and the inner surface of the liner plate 20.

[0112] As described above, the shaft construction device of this embodiment is a device for constructing a shaft underground by assembling annular liner plates 20 in the height direction. This shaft construction device is equipped with a cylindrical cutting edge 51 that extends downward and has an inner diameter larger than the outer diameter of the liner plate 20, and an excavation section 53 that excavates the bottom of the hole 12 inside the cutting edge 51.

[0113] Furthermore, the shaft construction device includes a jack 56 that uses the existing liner plate 20 as a reaction force to press the cutting edge 51 downward, and an inner cylindrical portion 57 that is positioned inside the cutting edge 51 and has an inner diameter larger than the outer diameter of the liner plate 20, and is fixed to the jack 56 so as to be movable relative to the cutting edge 51.

[0114] Furthermore, the shaft construction method of this embodiment is a construction method in which annular liner plates 20 are assembled in the height direction to construct a shaft underground. The method for constructing this shaft involves repeatedly performing the following steps: an excavation step (step S108) in which an excavation section 53 excavates the bottom of the hole 12 inside a cylindrical cutting edge 51 that extends downward and has an inner diameter larger than the outer diameter of the liner plate 20; an extension step (step S108) in which a jack 56 pushes the cutting edge 51 downward using the existing liner plate 20 as a reaction force to lower the cutting edge 51; and an assembly step (step S116) in which the liner plate 20 is attached to the lower end of the lowest ring 20A when the cutting edge 51 has been lowered by at least one stage of the liner plate 20.

[0115] Furthermore, in the shaft construction method, during the extension process, an inner cylindrical portion 57, which is positioned inside the cutting edge 51 and has an inner diameter larger than the outer diameter of the liner plate 20, is fixed to the jack 56 so as to be movable relative to the cutting edge 51, and as the cutting edge 51 descends, the inner cylindrical portion 57 protrudes upward from the upper end of the cutting edge 51.

[0116] With this configuration, the inner cylindrical portion 57 is fixed to the jack 56 so as to be movable relative to the cutting edge 51 and protrudes upward from the upper end of the cutting edge 51. This ensures safety inside the tunnel even if excavation of the bottom of the hole 12 is interrupted by an obstacle, for example.

[0117] Specifically, since the inner cylindrical portion 57 is fixed to the jack 56 so as to be movable relative to the cutting edge 51, the inner cylindrical portion 57 can protrude above the upper end of the cutting edge 51 as the cutting edge 51 descends due to the extension of the jack 56.

[0118] Furthermore, because the inner diameter of the inner cylindrical portion 57, which is positioned inside the cutting edge 51, is larger than the outer diameter of the liner plate 20, the portion of the inner cylindrical portion 57 that protrudes from the upper end of the cutting edge 51 faces the hole wall 11a. Therefore, the shaft construction device and shaft construction method allow the inner cylindrical portion 57 to function as a temporary earth retaining structure positioned on the outer circumferential surface side of the existing liner plate 20.

[0119] As a result, the shaft construction device and shaft construction method can prevent soil that has collapsed from the borehole wall 11a from flowing into the inside of the cutting edge 51 from between the upper end of the cutting edge 51 and the lower end of the existing liner plate 20, thanks to the inner cylindrical portion 57. Therefore, the shaft construction device and shaft construction method can ensure safety inside the shaft without having to install separate earth retaining structures, even if the excavation of the bottom of the hole 12 is interrupted, for example, by an obstruction.

[0120] In addition, since it is not necessary to separately install earth retaining structures in the shaft after interrupting excavation of the bottom of the hole 12, the shaft construction device and shaft construction method enable the removal of obstacles safely and efficiently.

[0121] Furthermore, the jack 56 comprises a main body 561 that extends and retracts in the height direction, and a spreader 562 provided at the tip of the main body 561 that contacts the lower end of the existing liner plate 20. Furthermore, since the cylinder 561a is fixed to the cutting edge 51 and the inner cylindrical portion 57 is fixed to the spreader 562, the shaft construction device can achieve the descent of the cutting edge 51 and the protrusion of the inner cylindrical portion 57 with a simple configuration.

[0122] Furthermore, since the inner cylindrical portion 57 is fixed to the spreader 562 of the jack 56 which contacts the existing liner plate 20, the inner cylindrical portion 57 can be positioned at the desired location as if it were fixed to the existing liner plate 20. As a result, the shaft construction device can better prevent the exposure of the borehole wall 11a as the cutting edge 51 descends, and can also resist the earth pressure from soil that collapses from the borehole wall 11a.

[0123] Furthermore, since the outer circumferential surface of the inner cylindrical portion 57 faces at least the upper part of the inner circumferential surface of the cutting edge 51, the shaft construction device can prevent the hole wall 11a from being exposed between the upper end of the cutting edge 51 and the lower end of the inner cylindrical portion 57 when the jack 56 is extended.

[0124] As a result, the shaft construction device can prevent soil and debris that have collapsed from the borehole wall 11a from overflowing the upper end of the cutting edge 51 and flowing into the interior of the cutting edge 51, thereby further improving safety inside the shaft.

[0125] Furthermore, since the upper end of the inner cylindrical portion 57 is in contact with or close to the backfill material 30 that is filled between the outer surface of the liner plate 20 one step above the lowest ring 20A and the hole wall 11a, the shaft construction device can prevent the hole wall 11a from being exposed between the upper end of the inner cylindrical portion 57 and the lower end of the backfill material 30.

[0126] As a result, the shaft construction device can prevent soil and debris that have collapsed from the borehole wall 11a from overflowing the upper end of the inner cylindrical section 57 and flowing into the cut-off opening 51, thereby further improving safety inside the shaft.

[0127] Furthermore, since the vertical length of the inner cylindrical portion 57 is longer than the vertical length of one liner plate 20, the shaft construction device can prevent a gap from forming between the lower end of the inner cylindrical portion 57 and the upper end of the cutting edge 51, even when the cutting edge 51 descends below the lower end of the lowest ring 20A.

[0128] Therefore, the shaft construction device can reliably prevent the hole wall 11a from being exposed above the cutting edge 51 by the inner cylindrical portion 57. As a result, the shaft construction device can prevent soil and debris that have collapsed from the borehole wall 11a from overflowing the upper end of the cutting edge 51 and flowing into the interior of the cutting edge 51, thereby further improving safety inside the shaft.

[0129] Furthermore, since multiple jacks 56 are provided at predetermined intervals in the circumferential direction of the cutting edge 51, the shaft construction device can stably support the inner cylindrical portion 57 inside the cutting edge 51 and move the inner cylindrical portion 57 relative to the cutting edge 51 in a balanced manner. This allows the shaft construction device to stably protrude the inner cylindrical portion 57 above the cutting edge 51.

[0130] Furthermore, since a work platform 54 supported by the cutting edge 51 is provided below the inner cylindrical portion 57, the outer circumferential surface of the cutting edge 51 and the outer circumferential surface of the inner cylindrical portion 57 face the hole wall 11a, and the work platform 54 is positioned above the bottom of the hole 12.

[0131] Therefore, the shaft construction device can prevent soil and sand from falling into the bottom of the hole 12 through the cutting edge 51, the inner cylindrical section 57, and the working platform 54. As a result, the shaft construction device can support the safe removal of obstacles by the worker M.

[0132] Furthermore, since a blocking member 58 is detachably provided to block the space between the lower end of the existing liner plate 20 and the hole wall 11a, when the shaft construction device houses the inner cylindrical portion 57 inside the cutting edge 51 in order to fill the space between the outer surface of the existing liner plate 20 and the hole wall 11a with backfill material 30, the opening that is created between the existing liner plate 20 and the cutting edge 51 can be closed by the blocking member 58.

[0133] Therefore, for example, the blocking member 58 can prevent soil that has collapsed from the hole wall 11a before the backfill material 30 is filled from flowing into the inside of the cutting edge 51 through the opening between the existing liner plate 20 and the cutting edge 51. Therefore, the shaft construction device can ensure safety inside the shaft not only when excavation of the bottom of the hole 12 is interrupted, but also before the backfill material 30 is filled.

[0134] Furthermore, since the cutting edge 51 and the inner cylindrical portion 57 are made of the same material and have the same thickness, the cutting edge 51 and the inner cylindrical portion 57 can reliably withstand the earth pressure from the collapsed soil when the borehole wall 11a collapses. As a result, the shaft construction device can prevent the collapsed soil from flowing into the shaft, thereby more reliably ensuring safety inside the shaft.

[0135] In the correspondence between the structure of this invention and the embodiments described above, The shaft construction apparatus of this invention corresponds to the excavation unit 50 and control unit 60 of the embodiment, The same applies to the following: The pre-assembled liner plate is compatible with the existing liner plate 20 and the bottom ring 20A. The telescopic mechanism is compatible with jack 56. The retractable main body corresponds to the main body 561. The contact portion corresponds to the spreader 562, The excavation process and extension process correspond to step S108. The assembly process corresponds to step S116, This invention is not limited to the configuration of the embodiments described above, and many other embodiments can be obtained.

[0136] For example, in the embodiment described above, the liner plate 20, the cutting edge 51, and the inner cylindrical portion 57 are cylindrical, but the invention is not limited to this, and they may be substantially rectangular or otherwise cylindrical. Furthermore, although the liner plate 20 is placed inside the opening pipe 70, the method is not limited to this, and a liner plate 20 that is exposed above the ground surface 10a may be assembled on the upper side of the first ring 21.

[0137] Furthermore, although the cutting edge 51 and the inner cylindrical portion 57 are made of the same material, steel, this is not limited to this, and any suitable material may be used as long as the configuration can withstand the soil pressure from the collapsed soil. For example, the inner cylindrical portion 57 and the cutting edge 51 may be made of different materials. Furthermore, although the cutting edge 51 and the inner cylindrical portion 57 are made of the same thickness, this is not limited to this, and any appropriate thickness is acceptable as long as the structure can withstand the soil pressure from the collapsed soil. For example, the thickness of the inner cylindrical portion 57 may be made thinner or thicker than the thickness of the cutting edge 51.

[0138] Furthermore, although the beam-shaped support portions 522 of the support frame 52 are arranged in three directions from the central support portion 521 toward the inner surface 51a of the cutting edge, the arrangement is not limited to this, and the beam-shaped support portions 522 may be arranged in a grid or lattice pattern surrounding the central support portion 521.

[0139] Furthermore, although the display unit 63 and the operation unit 64 are located on the ground and the excavation unit 53 is configured to be remotely operated, the display unit 63 and the operation unit 64 may also be located on the work platform 54 so that they can be operated by a worker M working on the work platform 54.

[0140] Furthermore, although the jack 56 that moves the cutting edge 51 and the inner cylindrical portion 57 relative to each other is configured as a hydraulic jack, it is not limited to this, and any telescopic mechanism with an appropriate configuration may be used as long as it allows for relative movement between the cutting edge 51 and the inner cylindrical portion 57.

[0141] Furthermore, although the second ring 22 was assembled after filling the space between the first ring 21 and the hole wall 11a with backfill material 30, the method is not limited to this. The backfill material 30 may also be filled between the first ring 21 and the hole wall 11a at the same time as filling the space between the second ring 22 and the hole wall 11a after assembling the second ring 22.

[0142] Furthermore, although the cutting edge 51 was lowered while excavating the bottom of the hole 12, the method is not limited to this, and the cutting edge 51 may be lowered after excavating the bottom of the hole 12. In addition, although worker M remotely operated the excavation unit 53 using the operation unit 64 to excavate the bottom of the hole 12, the method is not limited to this, and the bottom of the hole 12 may also be automatically excavated by control of the control unit 66.

[0143] Specifically, based on the signal indicating the excavation status of the hole bottom 12 detected by the sensor 62 and the video image data of the hole bottom 12 captured by the camera 61, the control unit 66 automatically determines the excavation status of the hole bottom 12. Then, based on the determination result, the control unit 66 automatically controls the operation of the excavation unit 53 to excavate the hole bottom 12 inside the cutting edge 51.

[0144] Furthermore, a soil discharge sensor for detecting the loading status of excavated soil into the soil discharge bucket 552 and a position sensor for detecting the vertical position of the soil discharge bucket 552 may be connected to the control unit 66. In this case, the control unit 66 automatically controls the operation of the lifting winch and the operation of the excavation unit 53 based on the loading status of excavated soil into the soil discharge bucket 552 and the position information of the soil discharge bucket 552.

[0145] In addition, the system may be configured to not only detect the excavation status of the hole bottom 12 with the sensor 62, but also to capture images of the hole bottom 12 with multiple cameras 61, and to automatically detect the excavation status of the hole bottom 12 based on the captured video data and control the drive of the excavation unit 53.

[0146] Thus, a control unit 66 for controlling the drilling unit 53 and a sensor 62 for detecting the condition of the drilling location at the bottom of the hole 12 to be drilled by the drilling unit 53 are provided. The control unit 66 controls the drilling of the drilling unit 53 based on the detection results of the sensor 62, so that the drilling location can be drilled with the drilling unit 53 under automatic operation control. As a result, the amount of work performed by the worker M inside the hole is reduced, improving the working environment and increasing efficiency. [Explanation of Symbols]

[0147] 12…Bottom of hole 20… Liner plate 20A...Bottom ring 30…Backing material 50…Drilling Unit 51...Blade mouth 53...Excavation section 54…Work platform 56... Jack 57...Inner cylinder part 58… Barrier member 60…Control Unit 561...Main body 562... Spreader

Claims

1. A shaft construction device that constructs a shaft underground by assembling annular liner plates in the vertical direction, A cylindrical cutting edge extending downwards, having an inner dimension larger than the outer dimension of the liner plate, A drilling section for drilling the bottom of the hole inside the cutting edge, An extension / retraction mechanism that uses the existing assembled liner plate as a reaction force to press the cutting edge downward, An inner cylindrical portion is provided, which is positioned inside the cutting edge and has an inner dimension larger than the outer dimension of the liner plate, and is fixed to the telescopic mechanism so as to be movable relative to the cutting edge. A device for constructing vertical shafts.

2. The telescopic mechanism comprises a telescopic main body that extends and retracts in the height direction, and a contact portion provided at the tip of the telescopic main body that abuts against the lower end of the assembled liner plate. The aforementioned retractable body is fixed to the blade opening, The inner cylindrical portion is fixed to the contact portion. The shaft construction apparatus according to claim 1.

3. The outer circumferential surface of the inner cylindrical portion is configured to face at least the upper part of the inner circumferential surface of the cutting edge. The shaft construction apparatus according to claim 1.

4. The upper end of the inner cylindrical portion is in contact with or close to the backfill material that has been filled between the outer surface of the assembled liner plate one level above the lowest level and the hole wall. The shaft construction apparatus according to claim 1.

5. The length in the height direction of the inner cylindrical portion is longer than the length in the height direction of one of the liner plates. The shaft construction apparatus according to claim 1.

6. Multiple telescopic mechanisms are provided at predetermined intervals in the circumferential direction of the blade opening. The shaft construction apparatus according to claim 1.

7. Below the inner cylindrical portion, a work platform supported by the cutting edge is provided. The shaft construction apparatus according to claim 1.

8. A detachable barrier member is provided to block the space between the lower end of the existing assembled liner plate and the hole wall. The shaft construction apparatus according to claim 1.

9. A method for constructing a shaft underground by assembling annular liner plates in the vertical direction, The drilling process involves a drilling section excavating the bottom of a hole inside a cylindrical cutting edge that extends downward and has an internal dimension larger than the external dimension of the liner plate, An extension process in which the extension mechanism uses the existing assembled liner plate as a reaction force to press the cutting edge downwards and lower the cutting edge, With the cutting edge lowered by at least one step of the liner plate, the assembly process of attaching the liner plate to the lower end of the lowest assembled liner plate is repeated. In the extension process, An inner cylindrical portion, positioned inside the cutting edge and having an inner dimension larger than the outer dimension of the liner plate, is fixed to the telescopic mechanism so as to be movable relative to the cutting edge, and protrudes upward from the upper end of the cutting edge as the cutting edge descends. Methods for constructing vertical shafts.

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