Non open-cut jacking method

Abstract

To facilitate drilling operations.SOLUTION: A non open-cut jacking method for burying a box body underground by replacing a box-shaped roof that is formed of a plurality of roof pipes and buried underground with the box body is provided. The non open-cut jacking method includes: a fixing step for fixing a drilling machine 20 within a beginning roof pipe 93 of a roof pipe line; an excavation step for excavating the natural ground located in front of the beginning roof pipe with the drilling machine; and a propulsion step for advancing the roof pipe line after excavation by the drilling machine. The drilling machine has a stationary portion 21 that can travel within the roof pipes and can be fixed to the inside of the beginning roof pipe, and the stationary portion has a fixing mechanism 30 capable of fixing the stationary portion by stretching between a floor face 93A and a ceiling face 93B of the beginning roof pipe.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to trenchless jacking methods. [Background technology]

[0002] For example, trenchless jacking methods, such as the well-known R&C method and SFT method, are known as methods for constructing underground tunnels that cross over existing above-ground objects such as roads and railways. This trenchless jacking method generally replaces a box-shaped roof, formed from multiple roof pipes and buried underground, with a box structure (box culvert), which serves as an underground structure. The box-shaped roof is constructed by arranging rows of roof pipes, each consisting of multiple roof pipes connected in series, in parallel along the outer edge of the box structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-172929 Summary of the Invention [Problem to be solved by the invention]

[0004] In trenchless jacking, excavation of the ground and insertion of the roof pipe are repeated from the starting point at the rear to the destination at the front. However, currently, excavation of the ground is carried out manually by workers who enter the front roof pipe. Excavation work is difficult, mainly involving chipping, and the space inside the roof pipe is very narrow for workers, making the excavation work extremely difficult.

[0005] The present disclosure has been devised in light of the above circumstances, and its purpose is to provide a trenchless jacking method that can facilitate excavation work. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, A trenchless jacking method in which a box-shaped roof formed by a plurality of roof pipes and buried in the ground is replaced with a box body, and the box body is buried in the ground, The box-shaped roof is configured by arranging a row of roof pipes, each row being formed by connecting a plurality of the roof pipes in series, in parallel along the outer edge of the box body, The non-excavation jacking method is a fixing step of fixing an excavator within the leading roof pipe of the row of roof pipes; an excavation step of excavating the natural ground located in front of the leading roof pipe by the excavator; a propelling step of advancing the row of roof pipes after excavation by the excavator; Equipped with The excavator is a fixing part that can travel inside the roof pipe and be fixed inside the leading roof pipe; a forward / backward moving unit provided on the fixed unit so as to be movable in a forward / backward direction relative to the fixed unit; a swivel unit provided on the front-rear moving unit so as to be rotatable about a first axis extending in the up-down direction relative to the front-rear moving unit; a rotating portion provided on the turning portion so as to be rotatable about a second axis extending in the front-rear direction relative to the turning portion; an undulating portion provided on the rotating portion so as to be rotatable around a third axis extending in the left-right direction relative to the rotating portion; an instrument mounting portion provided on the undulating portion so as to be rotatable around a fourth axis extending in the left-right direction relative to the undulating portion; a drilling tool attached to the tool attachment portion; Equipped with The fixing portion has a fixing mechanism that can fix the fixing portion by being stretched between the floor surface and the ceiling surface of the leading roof pipe. The present invention provides a trenchless jacking method characterized by the above.

[0007] Preferably, the fixing mechanism has an extension tube that is extendable and retractable in the vertical direction, and a fixing cylinder that extends and retracts the extension tube.

[0008] Preferably, the plurality of telescopic tubes are connected by a connecting member, and the fixing cylinder raises and lowers the connecting member to simultaneously extend and retract the plurality of telescopic tubes.

[0009] Preferably, a pair of front and rear telescopic tubes, the connecting member connecting the pair of front and rear telescopic tubes, and the fixing cylinder are provided on both the left and right sides of the fixing part. [Effects of the Invention]

[0010] According to the present disclosure, excavation work can be facilitated. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram for explaining an overview of a trenchless jacking method. [Figure 2] The front roof pipe is shown, (A) is a side view, and (B) is a rear view. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI in FIG. [Figure 7] FIG. [Figure 8] FIG. 10 is a side view showing the state when the excavator enters the leading roof pipe at the start of excavation. [Figure 9] FIG. 10 is a side view showing the state when the excavator enters the leading roof pipe at the start of excavation. [Figure 10] FIG. 1 is a side view showing a series of steps of the method. [Figure 11] FIG. 1 is a side view showing a series of steps of the method. [Figure 12]FIG. 1 is a side view showing a series of steps of the method. [Figure 13] FIG. 1 is a side view showing a series of steps of the method. [Figure 14] FIG. 1 is a side view showing a series of steps of the method. [Figure 15] FIG. 1 is a side view showing a series of steps of the method. [Figure 16] FIG. 1 is a side view showing a series of steps of the method. [Figure 17] FIG. 10 is a rear view showing the excavator when it is secured in place. [Figure 18] FIG. [Figure 19] FIG. 1 is a rear view conceptually showing the excavation area of ​​the face. [Figure 20] FIG. 10 is a view showing a digging tool of a second embodiment. [Figure 21] FIG. 4 is a side view showing an excavator according to a second embodiment. [Figure 22] FIG. 4 is a plan view showing an excavator according to a second embodiment. [Figure 23] FIG. 10 is a side view showing the operation of the excavator of the second embodiment. [Figure 24] FIG. 10 is a side view showing the operation of the excavator of the second embodiment. [Figure 25] FIG. 10 is a side view showing the state of advance excavation. [Figure 26] FIG. 10 is a side view showing the operation of the excavator of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the present disclosure is not limited to the following embodiments.

[0013] [First embodiment] 1 is a diagram for explaining an outline of the trenchless jacking method. The trenchless jacking method of this embodiment (also referred to as the present method) is generally an improvement over the known R&C method.

[0014] The front-to-back, left-to-right, up-to-down directions are as shown in the diagram. The arrival shaft 7, which is the arrival side, is the front side, and the departure shaft 6, which is the departure side, is the rear side. The front-to-back direction is horizontal, and the left-to-right direction is horizontal and perpendicular to the front-to-back direction. The up-to-down direction is vertical, and perpendicular to the front-to-back and left-to-right directions. Excavation is carried out forward.

[0015] In FIG. 1, (A1), (B1), (C), (D), and (E1) are side views, and (A2), (B2), and (E2) are rear views.

[0016] According to this construction method, as shown in (E1) and (E2), an underground passage (underpass) is constructed underground to cross a road 1, which is an above-ground object. The base of this underground passage is a box culvert 2, which serves as an underground structure. With this construction method, as shown in (B1) and (B2), a box-shaped roof 4 formed by multiple roof pipes 3 is buried underground in advance. This box-shaped roof 4 is then finally replaced by the box 2.

[0017] The box-shaped roof 4 is formed by arranging a roof pipe row 5, which is made up of multiple roof pipes 3 connected in series, in parallel along the outer edge of the box body 2. As shown in (B2), the box-shaped roof 4 has a U-shaped gate-shaped cross section that corresponds to the top wall and left and right side wall sections of the box body 2. The roof pipes 3 have a rectangular cross section. The roof pipes 3 and the roof pipe row 5 extend in the front-to-rear direction.

[0018] In this method, first, as shown in (A1) and (A2), the lead roof pipe 93 located at the head of the roof pipe row 5 is inserted into the ground. At this time, each time the ground is excavated a predetermined length, the lead roof pipe 93 is inserted into the ground by that excavation length. This excavation and insertion process is repeated. When the lead roof pipe 93 is almost completely inserted, the next roof pipe 3 is connected to the lead roof pipe 93, and excavation and insertion are repeated again to insert the roof pipe row 5. This insertion of the roof pipes 3 or roof pipe row 5 is performed using a pipe insertion jack (not shown). FC (friction cut) plates (not shown) are attached to the roof pipes 3 (including the lead roof pipe 93) to isolate them from the ground.

[0019] Once one roof pipe row 5 has penetrated the natural ground, the next roof pipe row 5 is inserted adjacent to the side (horizontal) of the previous roof pipe row 5. This insertion is repeated, and in the illustrated example, five roof pipe rows 5 are arranged side by side as shown in (A2). Note that pipe roof rows 5 located apart from each other may be excavated simultaneously. These roof pipe rows 5 correspond to the upper wall portion of the box body 2.

[0020] Next, as shown in (B1) and (B2), three roof pipe rows 5 are inserted below the roof pipe rows 5 located at both the left and right ends of the five roof pipe rows 5, starting from the top. These roof pipe rows 5 correspond to the left and right side wall portions of the box body 2. In this way, a box-shaped roof 4 with a portal cross section is formed.

[0021] Next, as shown in (C), a center push jack 8 is interposed between the front end face of the box body 2 and the rear end face of the box roof 4, and as shown in (D), the rear end face of the box body 2 is pushed forward by a main push jack 9, moving the box body 2 and the box roof 4 forward. This inserts the box body 2 into the ground, and the box roof 4 is pushed into the arrival shaft 7. After that, as shown in (E1) and (E2), the box body 2 is replaced with the box roof 4, and an underground structure is constructed beneath the road 1.

[0022] This construction method is characterized by the excavation required to insert the roof pipe row 5, as shown in (A1) and (A2). Conventionally, workers would enter the leading roof pipe 93 and perform the excavation manually. However, the excavation itself is difficult work that mainly involves chipping, and the space inside the leading roof pipe 93 is very narrow for workers, making the excavation work extremely difficult.

[0023] Therefore, in this embodiment, excavation is performed mechanically using an excavator, which will be described later, thereby greatly facilitating the excavation work. The trenchless jacking method of this embodiment will be described in detail below.

[0024] 2 shows the roof pipe 3, particularly the leading roof pipe 93. (A) is a side view, and (B) is a rear view.

[0025] The roof pipe 3 is a straight pipe with a rectangular cross section (specifically, a square), and its pipe central axis C extends in the front-to-rear direction. The roof pipe 3 is configured to be symmetrical both vertically and horizontally with respect to the pipe central axis C. One side of the rectangular cross section of the roof pipe 3 is relatively short, for example, about 800 to 1000 mm. Therefore, the space inside the roof pipe 3 is very narrow for workers. The length of the roof pipe 3 is, for example, about 3000 mm. The length of the roof pipe 3 constituting the leading roof pipe 93 may be different from that of the other roof pipes 3; for example, the latter may be twice as long as the former (for example, about 6000 mm).

[0026] In particular, the leading roof pipe 93 has a roof pipe 3 and a cutting edge 10 attached to the front end of the roof pipe 3. The leading roof pipe 93 is formed by connecting the cutting edge 10 to the roof pipe 3 coaxially in series.

[0027] The roof pipe 3 has a pipe body 11 with a rectangular cross section (specifically, a square) extending in the front-to-rear direction, and flanges 12 that protrude inward and are provided at the top, bottom, left, and right four corners of the front and rear ends of the pipe body 11. Here, "inward" refers to the direction approaching the pipe center axis C. The flanges 12 are welded to the inner peripheral surface of the pipe body 11 so that they are flush with the front and rear end faces of the pipe body 11.

[0028] The upper, lower, left, and right flanges 12 are spaced apart from one another, and gaps 13 are formed between each flange 12. The gaps 13 positioned above and below and extending horizontally (horizontal gaps) have a left-right width W1, and the gaps 13 positioned above and below and extending vertically (vertical gaps) have a vertical width W2. The left-right width W1 and the vertical width W2 are equal to each other. Each flange 12 is provided with a flange hole 15 for inserting a bolt 14 therethrough. The inner peripheral edge 16 of the flange 12 is formed in an arc shape along a circle centered on the pipe central axis C.

[0029] The roof pipe 3 has joints 17 that protrude from its outer circumferential surface and extend in the pipe longitudinal direction (i.e., the axial direction of the pipe central axis C). The joints 17 are used to position and adjust the distance with respect to the existing roof pipe 3, as shown by the imaginary lines in (B). In this embodiment, a pair of simple plate-shaped joints 17, one above the other, are provided on the left and right outer surfaces of the roof pipe 3. However, as is well known, the joints 17 may be L-shaped or have other shapes, and the installation positions of the joints 17 may be changed depending on the presence or absence of the mating roof pipe 3 and its relative position.

[0030] The cutting edge 10 is also formed in the shape of a tube with a rectangular cross section (specifically, a square) extending in the front-to-rear direction, and has the same cross section as the roof pipe 3. Similar to the roof pipe 3, the rear end of the cutting edge 10 is provided with upper, lower, left and right flanges 12 and gaps 13 between each flange 12. The cutting edge 10 does not have a joint portion 17.

[0031] The front end face 18 of the cutting edge 10 is formed by an upper front end face 18A that is perpendicular to the pipe central axis C, and a lower front end face 18B that is inclined relative to the direction perpendicular to the pipe central axis C. The lower front end face 18B is inclined so that it slopes more rearward as it extends downward. In this way, the front end face 18 of the cutting edge 10 is formed in a V-shape when viewed from the side.

[0032] By attaching such cutting edge 10, an appropriate angle of repose can be given to the face formed in front of cutting edge 10.

[0033] When assembling the leading roof pipe 93, the rear end face of the cutting edge 10 is placed adjacent to the front end face of the roof pipe 3, and bolts 14 are inserted from the rear into the flange holes 15 of both. Then, nuts 19 are fastened to the parts of the bolts 14 that protrude from the flange holes 15 of the cutting edge 10. This secures the cutting edge 10 to the roof pipe 3. Note that the insertion direction of the bolts 14 may be reversed.

[0034] Here, the leading roof pipe 93 means the roof pipe 3 to which the cutting edge 10 is attached, and is conceptually included in the roof pipes 3. No cutting edge 10 is attached to any roof pipe other than the leading roof pipe 93. Furthermore, the leading roof pipe 93 refers to the leading roof pipe in the roof pipe row 5 at the insertion stage, and does not refer to the leading roof pipe in the roof pipe row 5 after insertion has been completed, because the cutting edge 10 has been removed. The cutting edge 10 is also conceptually included in the roof pipe 3.

[0035] The roof pipe row 5 is configured by connecting one or more roof pipes 3 in series behind the leading roof pipe 93 by flange connections similar to those described above. However, in a broad sense, even if no roof pipes 3 are connected behind the leading roof pipe 93, i.e., if there is only the leading roof pipe 93, this is still considered to be a roof pipe row 5 with only one roof pipe 3.

[0036] The trenchless jacking method of this embodiment generally includes the following steps: (1) A fixing step of fixing the excavator inside the leading roof pipe 93 in the roof pipe row 5. (2) An excavation step in which the ground (i.e., the working face) located in front of the leading roof pipe 93 is excavated by an excavator. (3) A propulsion step for advancing the roof pipe row 5 after excavation by the excavator.

[0037] The following describes the excavator, which is a characteristic component of this embodiment.

[0038] 3 to 5 are side, plan, and rear views showing the excavator 20 disposed inside the leading roof pipe 93. For ease of understanding, the excavator 20 and the leading roof pipe 93 are drawn transparently. Also, Fig. 5 shows a schematic cross section.

[0039] The excavator 20 is an open-type excavator. The excavator 20 comprises a fixed part 21 that is capable of traveling within the roof pipe 3 and that is capable of being fixed within the leading roof pipe 93, and a front-rear moving part 22 that is provided on the fixed part 21 so as to be movable in the front-rear direction relative to the fixed part 21. The excavator 20 also comprises a swivel part 23 that is provided on the front-rear moving part 22 so as to be rotatable or swiveling relative to the front-rear moving part 22 about a first axis C1 that extends in the up-down direction, and a rotating part 24 that is provided on the swivel part 23 so as to be rotatable relative to the swivel part 23 about a second axis C2 that extends in the front-rear direction. The excavator 20 also includes a hoisting section 25 provided on the rotating section 24 so as to be rotatable around a third axis C3 extending in the left-right direction relative to the rotating section 24, an implement mounting section 98 provided on the hoisting section 25 so as to be rotatable around a fourth axis C4 extending in the left-right direction relative to the hoisting section 25, and an excavation implement 26 attached to the implement mounting section 98.

[0040] The orientations of the above-mentioned axes C1 to C4 are those assuming that the excavator 20 is in the basic posture as shown in the figure. Naturally, rotation or pivoting around one axis will cause the orientation of the other axes to change. The components of the excavator 20, namely the fixed unit 21, the forward / backward moving unit 22, the swivel unit 23, the rotating unit 24, the elevation / tilting unit 25, the tool mounting unit 98, and the excavation tool 26, are arranged in this order from roughly rear to front. The rotation mechanisms that allow pivoting or rotation around the axes C1 to C4 are formed by well-known combinations of shafts and bearings, etc.

[0041] For convenience, the second axis C2 is assumed to be on the central axis (referred to as the machine central axis) CM of the excavator 20. In a plan view such as that shown in Fig. 4, the machine central axis CM is positioned at approximately the same position as the pipe central axis C, and the excavator 20 is configured symmetrically with respect to the machine central axis CM. In addition, in a side view such as that shown in Fig. 3, the height position of the machine central axis CM relative to the pipe central axis C changes, as will be described in detail later.

[0042] The fixed portion 21 comprises a chassis frame 27, an outer tube 28 fixed to the chassis frame 27 and extending in the fore-and-aft direction, a conveyor 29 rotatably mounted on the chassis frame 27, a fixing mechanism 30 for fixing the fixed portion 21 inside the leading roof pipe 93, and front and rear wheel portions 31F, 31R that run on the floor surface 93A of the roof pipe 3 to move the fixed portion 21 in the fore-and-aft direction.

[0043] The chassis frame 27 is constructed by assembling steel materials such as square pipes into a box frame shape. The outer pipe 28 is a pipe with a rectangular cross section that is open at the front end and closed at the rear end, and the inner pipe 32 of the forward / rearward moving part 22 is inserted into this so that it can slide forward and backward (see Figure 5).

[0044] The conveyor 29 is used to transport the earth and sand excavated from the face from the front end to the rear end of the excavator 20. The conveyor 29 is arranged under the outer pipe 28 so as to go under the outer pipe 28. The conveyor 29 is rotatable around a fifth axis C5 extending in the left-right direction, and this rotation raises and lowers the front end of the conveyor 29. In the basic position shown in the figure, the conveyor 29 is in the raised position. The conveyor in this embodiment is formed by a flight conveyor, but the type of conveyor is arbitrary.

[0045] The fixing mechanism 30, which will be described in detail later, is tensioned between the floor surface 93A and ceiling surface 93B of the leading roof pipe 93 to fix the fixing part 21 (see Figures 11A and 17). The fixing mechanism 30 has an extension tube 33 that is extendable in the vertical direction, and a fixing cylinder 34 that extends and retracts the extension tube 33. Furthermore, multiple extension tubes 33 are connected by connecting members 35, and the fixing cylinder 34 extends and retracts the multiple extension tubes 33 simultaneously by raising and lowering the connecting member 35.

[0046] More specifically, a pair of telescopic tubes 33 are provided on the left and right sides, one in front and one in back. The telescopic tubes 33 are configured to extend and retract by the telescopic inner tube 33B moving up and down below the telescopic outer tube 33A fixed to the chassis frame 27. Similarly, the fixing cylinder 34 is configured to extend and retract by the piston rod 34B moving up and down below the cylinder body 34A fixed to the chassis frame 27. The fixing cylinder 34 is formed by a hydraulic cylinder. The same applies to the cylinders described below unless otherwise specified.

[0047] For example, in the configuration on the left side shown in Figure 3, the telescopic inner tubes 33B of the front and rear telescopic tubes 33 are connected to each other by a connecting member 35. The connecting member 35 is formed, for example, from a square pipe. The tip or bottom end of the piston rod 34B of the fixing cylinder 34, which is arranged in an inverted state, is rotatably connected to the middle position of the connecting member 35 in the front and rear.

[0048] With this configuration, two telescopic tubes 33 can be extended and retracted simultaneously with one fixing cylinder 34, thereby achieving a smaller and less expensive working machine.

[0049] The configuration on the right side is symmetrical to the configuration on the left side, so a description thereof will be omitted.

[0050] In the illustrated basic position, the telescopic tube 33 and the fixing cylinder 34 are contracted, and the telescopic inner tube 33B is in a raised position away from the floor surface 93A. On the other hand, as will be described in detail later, when the telescopic tube 33 and the fixing cylinder 34 are extended, the telescopic inner tube 33B descends and abuts against the floor surface 93A, and the resulting reaction force lifts the fixed part 21 and the entire excavator 20. Then, when the telescopic outer tube 33A abuts against the ceiling surface 93B, the tensioning is completed, and the fixed part 21 and the entire excavator 20 are fixed in the raised position (see Figures 11A and 17). Since tensioning and fixing are performed by the telescopic tubes 33 at four locations (front, rear, left, and right), the entire excavator 20 can be firmly and stably fixed.

[0051] The front and rear wheel sections 31F, 31R are attached to the underside of the conveyor 29 and are disposed at the center of the excavator 20 in the left-right direction.

[0052] The rear wheel unit 31R includes a pair of left and right wheels 36 that serve as drive wheels, a support member 37 that is attached to the underside of the conveyor 29 and rotatably supports the pair of wheels 36, a motor 38 that is attached to the underside of the conveyor 29 and drives the pair of wheels 36 to rotate, and a transmission mechanism that transmits the driving force of the motor 38 to the wheels 36. The transmission mechanism in this embodiment is formed by a chain and sprocket mechanism, of which only the sprocket 39 is shown in FIG. 5. The sprocket 39 is coaxially sandwiched and fixed between the left and right wheels 36. The transmission mechanism may also be formed by another mechanism such as a gear mechanism.

[0053] 6, the front wheel unit 31F includes a pair of front and rear wheels 40 that are driven wheels, a pair of left and right support members 41 that rotatably support the pair of wheels 40, and support legs 42 that are attached to the underside of the conveyor 29 and support the support members 41 so that they can swing in the front-rear direction. As shown in FIG. 6, the left and right support members 41 partially cover the left and right side surfaces of the wheels 40.

[0054] The excavator 20 of this embodiment can pass through the flange connection portion of the roof pipe 3 while traveling. To make this possible, the front and rear wheel sections 31F, 31R are able to pass through the gap 13 between the lower left and right flanges 12.

[0055] As shown in Fig. 5, within the range of height H1 of the gap 13, the left-right width of the rear wheel section 31R, specifically the overall width WR of the left and right wheels 36, is smaller than the width W1 of the gap 13. Also, as shown in Fig. 6, within the range of height H1 of the gap 13, the left-right width of the front wheel section 31F, specifically the overall width WF of the left and right support members 41, is smaller than the width W1 of the gap 13.

[0056] As will be described in more detail later, the excavator 20 can move in and out between the inside and outside of the roof pipe row 5 through the rear end opening of the roof pipe row 5 by traveling on the wheel sections 31F, 31R. This is because the front and rear wheel sections 31F, 31R can pass through the gap 13 between the lower left and right flanges 12 located at the rear end of the roof pipe row 5.

[0057] In this way, the excavator 20 of this embodiment travels independently using the front and rear wheel sections 31F, 31R located at the center of the width in the left-right direction. However, due to this structure, the excavator 20 may lack stability in the left-right direction and may be prone to tipping over.

[0058] Therefore, the excavator 20 of this embodiment is provided with anti-tip mechanisms 43 symmetrically on both the left and right sides thereof to prevent the excavator 20 from tipping over in the left-right direction.

[0059] 4, the tip-over prevention mechanism 43 includes a pair of front and rear buffer mechanisms 44 provided on the sides of the fixed part 21. These buffer mechanisms 44 are configured symmetrically in the front and rear directions.

[0060] The buffer mechanism 44 has a roller 45 that can come into contact with the inner surface of the roof pipe 3, and a buffer member 46 that urges the roller 45 so as to press the roller 45 against the inner surface. In this embodiment, the roller 45 is made of a resin roller, and the buffer member 46 is made of a gas spring.

[0061] A bracket 47 is attached to the telescopic outer tube 33A, and the base end of a swing arm 48 is rotatably attached to the bracket 47. A roller 45 is rotatably attached to the tip end of the swing arm 48. A buffer member 46 is arranged in a compressed state between the telescopic outer tube 33A and the swing arm 48. When the buffer member 46 presses the swing arm 48, the roller 45 is pressed against the inner surface of the roof pipe 3.

[0062] A total of four buffer mechanisms 44 on the front, back, left and right sides constantly urge the fixed part 21 toward the center in the left-right direction, thereby keeping the excavator 20 upright and effectively preventing the excavator 20 from tipping over in the left-right direction.

[0063] When the excavator 20 is traveling, the rollers 45 rotate while pressed against the inner surface of the roof pipe 3, and the excavator 20 travels on the inner surface of the roof pipe 3. Therefore, the excavator 20 can be kept stably upright even when traveling, and the excavator 20 can be prevented from tipping over in the left-right direction.

[0064] As shown in Figure 5, the left and right anti-tip mechanisms 43 are able to pass through gaps 13 between the upper and lower flanges 12 on both the left and right sides so that the excavator 20 can pass through the flange connection parts of the roof pipes 3 when traveling. More specifically, within the range of height H2 (= H1) of the gap 13, the vertical width of the left and right anti-tip mechanisms 43, specifically the width WS of the rollers 45 in the left and right buffer mechanisms 44, is made smaller than the width W2 of the gap 13, so that the rollers 45 can pass through the gap 13. This also allows the excavator 20 to move in and out between the inside and outside of the roof pipe row 5 through the rear end opening of the roof pipe row 5.

[0065] Next, the front-rear moving unit 22 will be described. The front-rear moving unit 22 has an inner tube 32 inserted into the outer tube 28 of the fixed unit 21 described above so as to be slidable forward and backward (see FIGS. 3 and 5), and a movable frame 49 fixed to the front end of the inner tube 32 at a position forward of the outer tube 28. The front-rear moving unit 22 and the fixed unit 21 are connected by left and right front-rear moving cylinders 50, and the front-rear moving unit 22 is moved in the front-rear direction relative to the fixed unit 21 by the extension and contraction of these cylinders 50. The rear end of the cylinder 50 (formed by the cylinder body) is rotatably connected to the telescopic outer tube 33A of the rear telescopic tube 33. The front end of the cylinder 50 (formed by the piston rod) is rotatably connected to the movable frame 49. The central axes of the outer tube 28 and the inner tube 32 are coaxial with the machine central axis CM.

[0066] Next, the swivel unit 23 will be described (see FIGS. 3 and 4). The swivel unit 23 has a swivel frame 51. The swivel frame 51 is attached to the movable frame 49 so as to be swivelable around the first axis C1, as if sandwiched between the movable frame 49 from above and below. The swivel frame 51 is positioned in front of the movable frame 49.

[0067] Next, the rotating unit 24 will be described (see Figures 3 and 4). The rotating unit 24 has a rotating frame 52. The rotating frame 52 is positioned adjacent to the front side of the swivel frame 51 and is attached to the swivel frame 51 so as to be rotatable around the second axis C2. The swivel unit 23 and the rotating unit 24 are each driven by a hydraulic drive unit.

[0068] Next, the derrick unit 25 will be described (see Figures 3 and 4). The derrick unit 25 has a derrick arm 53 extending in the front-to-rear direction. The base or rear end of the derrick arm 53 is attached to the rotating frame 52 so as to be rotatable about the third axis C3. The derrick arm 53 and the rotating frame 52 are connected by left and right arm derrick cylinders 54, and the extension and contraction of these cylinders 54 causes the derrick arm 53 to move up and down or be raised and lowered in the vertical direction relative to the rotating frame 52. The rear end of the cylinder 54 (formed by the cylinder body) is rotatably connected to the rotating frame 52. The front end of the cylinder 54 (formed by the piston rod) is rotatably connected to the derrick arm 53.

[0069] Next, the tool mounting part 98 will be described (see Figures 3 and 4). The tool mounting part 98 has a tool mounting bracket 55. The tool mounting bracket 55 is attached to the tip or front end of the derricking arm 53 so as to be rotatable around the fourth axis C4. The rotation of the tool mounting part 98 or tool mounting bracket 55 can also be referred to as swinging.

[0070] The tool mounting bracket 55 and the derricking arm 53 are also connected by a semicircular arc-shaped drive link 56. Both ends of the drive link 56 are rotatably connected to the tool mounting bracket 55 and the derricking arm 53, respectively. This rotation is around an axis parallel to the fourth axis C4.

[0071] The drive link 56 and the derrick arm 53 are connected by an implement derrick cylinder 57, and the extension and contraction of this cylinder 57 causes the implement mounting bracket 55 to be raised and lowered in the vertical direction relative to the derrick arm 53. The rear end of the cylinder 57 (formed by the cylinder body) is rotatably connected to the vicinity of the base end of the derrick arm 53. The front end of the cylinder 57 (formed by the piston rod) is rotatably connected to the longitudinal middle of the drive link 56.

[0072] Next, a description will be given of the excavation tool 26. The excavation tool 26 is attached to the tool attachment bracket 55 by fasteners such as bolts so as to be detachable and replaceable.

[0073] Figure 7 shows the details of the excavation tool 26. (C) is a side view, (B) is a plan view, (A) is a VIIA-VIIA cross-sectional view of (B), and (D) is a VIID-VIID cross-sectional view of (B). It should be noted that the front-to-back, left-to-right, up-to-down directions shown in (C) are determined for the sake of convenience in explaining the positional relationships of each part, and do not directly relate to the directions of the roof pipe 3, excavator 20, etc. shown in Figure 3, etc.

[0074] The excavation tool 26 includes a shovel 26A, which, as is well known, has the functions of excavating the natural ground and scraping, raking, and scooping up the excavated soil. The shovel 26A has a base plate 58, which forms its base or rear end and serves as an attachment portion to the tool mounting bracket 55, and a shovel plate 59, which is fixed to the base plate 58 and extends from the base plate 58 toward the tip 59D or front end. The shovel 26A or shovel plate 59 is rectangular in plan view as shown in (B), and has a U-shaped cross section with an open bottom when viewed from the front as shown in (A). The shovel plate 59 has a bottom plate 59A for placing scooped soil and left and right side plates 59E extending vertically downward from the left and right edges of the bottom plate 59A. The bottom of the shovel plate 59 is open, forming an open portion 59F for receiving soil. The excavation tool 26, the shovel 26A or the tip 59D or front end of the shovel plate 59 are linear in plan view, so that the surface of the excavated soil can be made flat.

[0075] Further, a tip end portion 59B or the front part of the bottom plate 59A is inclined relative to a base end portion 59C or the rear part, and is inclined downward toward an open portion 59F or the bottom side as it approaches a tip end 59D or the front end. Correspondingly, the front parts of the left and right side plates 59E are also formed in a triangular shape.

[0076] Soil is poured into shovel 26A through opening 59F. Left and right side plates 59E prevent the poured soil from leaking out to the sides. When scooping soil with shovel 26A, shovel 26A is turned upside down from the illustrated position, and the soil is placed on bottom plate 59A.

[0077] A plurality of reinforcing ribs 60 are fixed to the back surface or top surface of the rear portion 59C of the bottom plate 59A by welding, etc. These reinforcing ribs 60 are also fixed to the base plate 58.

[0078] In the basic position shown in Fig. 3, excavation tool 26 is positioned so that tip 59D faces downward and open portion 59F faces rearward. On the other hand, in Fig. 4, for convenience, excavation tool 26 is shown in a position rotated approximately 90° upward from the basic position. At this time, tip 59D faces forward and open portion 59F faces downward.

[0079] The excavator 20 can be controlled manually or automatically, and can be controlled wirelessly or via a wire. In this embodiment, the excavator 20 is remotely controlled manually and via a wire from outside the roof pipe row 5. That is, the excavator 20 is connected via a wire to a control room located in the departure shaft 6, and an operator in the control room operates a controller to manually control the excavator 20. The excavator 20 is equipped with a light that illuminates the area ahead and a camera that captures the view ahead. The image from the camera is displayed on a monitor in the control room, and the operator controls the excavator 20 while watching the image.

[0080] Next, a trenchless jacking method (this method) of this embodiment using the above-described excavator 20 will be described.

[0081] As shown in Figure 8, at the start of excavation, the leading roof pipe 93 that will later form the roof pipe row 5 is placed adjacent to the natural ground G in the starting shaft 6. At this time, the tip face or front end face 18 of the cutting edge 10 of the leading roof pipe 93 is placed adjacent to the natural ground G.

[0082] In this embodiment, the excavator 20 is fixed inside the leading roof pipe 93, and excavation is carried out by the excavator 20 from the start of excavation.

[0083] As shown in Figures 8(A) and (B), the excavator 20 travels forward from the rear outside of the leading roof pipe 93 and enters the leading roof pipe 93. Then, as shown in Figures 9(A) and (B), the excavator 20 stops when it reaches the front end of the leading roof pipe 93 and is fixed at this position as described below.

[0084] The front wheel portion 31F of the excavator 20 can pass through the gap 13 between the lower left and right flanges 12 located at the rear end of the leading roof pipe 93 (i.e., the rear end of the roof pipe 3). Therefore, as shown in Figure 8(B), the excavator 20 can pass through the flanges 12 without any hindrance.

[0085] Also, the rear wheel portion 31R of the excavator 20 can pass through the same gap 13. Therefore, as shown in Figure 9(A), the excavator 20 can pass over the flange 12 without any hindrance.

[0086] The front and rear wheel sections 31F, 31R can also pass through the flange 12 that connects the cutting edge 10 and the roof pipe 3. Therefore, as shown in Figure 9(B), the excavator 20 can be positioned at the front end of the leading roof pipe 93 with the front wheel section 31F located roughly at the position of the flange 12 and the excavator 20 straddling the cutting edge 10 and the roof pipe 3.

[0087] After this, although not shown in the figures, the excavator 20 is fixed, excavation is carried out by the excavator 20, and the leading roof pipe 93 is advanced by the excavation length, and these excavation and advancement processes are repeated. Then, when the leading roof pipe 93 has been inserted into the natural ground G by a predetermined length, the next roof pipe 3 is connected to the rear end of the leading roof pipe 93, and excavation and advancement are repeated again. This process is repeated until the roof pipe row 5 has penetrated the natural ground G.

[0088] In this embodiment, excavation was performed by the excavator 20 from the beginning of excavation, but alternatively, excavation by the excavator 20 may be started after the leading roof pipe 93 has been inserted into a hole that has been excavated to some extent by hand.

[0089] Incidentally, during excavation, there may be cases where it is desired to remove the excavator 20 from inside the roof pipe row 5. For example, this may occur when it is discovered that obstacles that are difficult to dig out with the excavator 20, such as concrete rubble, garbage, sleepers, or boulders, are buried in the natural ground G, forcing workers to enter the roof pipe row 5 and manually dig out the obstacles. Because the inside of the roof pipe row 5 is extremely narrow, it is extremely difficult or virtually impossible for workers to perform such manual work while the excavator 20 remains installed.

[0090] However, if the excavator 20 of this embodiment is driven backward after being released from the lock, it can easily escape from inside the roof pipe row 5 to the outside through the rear end opening of the roof pipe row 5. Therefore, even if the above-mentioned trouble occurs, the excavator 20 can be easily removed, and an operator can enter the roof pipe row 5 to perform manual work.

[0091] Next, the fixing step, excavation step and advancing step of this construction method will be described in more detail.

[0092] 10 to 16B show a series of steps in order. Here, it is assumed that the leading roof pipe 93 and several subsequent roof pipes 3 have already been inserted into the ground G, and that the excavator 20 starts traveling forward within the roof pipe row 5 toward the leading roof pipe 93.

[0093] Figure 10(A) shows the excavator 20 in the basic position traveling forward toward the leading roof pipe 93. As described above, the front and rear wheel sections 31F, 31R and the left and right anti-tip mechanisms 43 (rollers 45) of the excavator 20 can pass through the gap 13 between the flanges 12. This allows the excavator 20 to pass over the flange 12 of the roof pipe 3 without hindrance. The left and right anti-tip mechanisms 43 prevent the excavator 20 from tipping over in the left or right direction, allowing the excavator 20 to travel stably while remaining upright.

[0094] 10(B) shows the state when the excavator 20 arrives at the leading roof pipe 93. As described above, the excavator 20 is positioned at the front end of the leading roof pipe 93 with the front wheel section 31F located approximately at the position of the flange 12 and the excavator 20 straddling the cutting edge 10 and the roof pipe 3.

[0095] 11(A) shows the state when the excavator 20 is fixed inside the leading roof pipe 93. At this time, the fixing cylinders 34 and telescopic tubes 33 on both the left and right sides are extended simultaneously. First, the telescopic inner tube 33B descends and abuts against the floor surface 93A, and the reaction force from this lifts the fixed part 21 and the entire excavator 20. Then, when the telescopic outer tube 33A abuts against the ceiling surface 93B, the tensioning is completed and the fixed part 21 and the entire excavator 20 are fixed in the raised position. Since the tensioning is performed by the telescopic tubes 33 at four locations on the front, back, left and right, the entire excavator 20 can be fixed firmly and stably. This completes the fixing step.

[0096] At this time, the front and rear wheel sections 31F, 31R are lifted and separated from the floor surface 93A. Figure 17 is a rear view showing the state when the excavator 20 is fixed. The rollers 45 of the left and right anti-toppling mechanisms 43 are positioned higher than the gaps 13 between the flanges 12.

[0097] 11(B) shows the state when the conveyor 29 of the excavator 20 is lowered and set to the working position. At this time, the front end of the conveyor 29 is positioned at the forefront end on the floor surface 93A inside the cutting edge 10.

[0098] 12 shows the excavator 20 in its initial state immediately before the start of excavation. At this time, the tool raising / lowering cylinder 57 is retracted, the tool mounting part 98 is rotated upward by approximately 90°, and the tip of the excavation tool 26 is slightly inserted into the part of the ground G located in front of the cutting edge 10, i.e., the working face K. The excavation tool 26 is in a horizontal position with the tip 59D facing forward and the open part 59F facing downward.

[0099] At this time, an automated trolley 61 is set at a standby position as shown in the figure near the rear end of the excavator 20. The automated trolley 61 is a self-propelled trolley that is loaded with excavated earth and sand and transports it to the outside of the roof pipe row 5, i.e., to the departure shaft 6. The standby position is directly below the rear end, which is the discharge end of the conveyor 29.

[0100] As shown in the side view of Fig. 12 and the plan view of Fig. 18, the motorized carriage 61 includes a chassis 62, front wheels 63 as driven wheels attached to the chassis 62, and rear wheels 64 as drive wheels, and a loading platform 65 detachably mounted on the chassis 62. The motorized carriage 61 also includes a motor that drives the rear wheels 64, a control device that controls the motor, and the like, although not shown.

[0101] Similar to the excavator 20, the front wheels 63 and rear wheels 64 are positioned at the center of the left-right width of the chassis 62 and can pass through the gap 13 between the flanges 12. The automated cart 61 also has a pair of front and rear side rollers 66 provided on the left and right to prevent it from tipping over (not shown in side views such as Figure 12). The side rollers 66 abut against the inner surfaces of the roof pipe 3 as appropriate to prevent the automated cart 61 from tipping over in the left-right direction.

[0102] The motorized vehicle 61 can also be controlled manually or automatically, and can be controlled wirelessly or by wire. In this embodiment, the motorized vehicle 61 is manually controlled by an operator in a control room, just like the excavator 20.

[0103] The automated trolley 61 is stopped at a standby position as shown in Figure 12, and receives onto its loading platform 65 the earth and sand carried out from the conveyor 29 during excavation work. Then, when a predetermined amount of earth and sand has piled up on the loading platform 65, the automated trolley 61 starts moving backward from the standby position. The automated trolley 61 travels backward within the roof pipe row 5 and eventually exits the roof pipe row 5. The automated trolley 61 is stopped when it reaches a predetermined discharge position outside. Then, the loading platform 65 is removed by an operator, and the earth and sand inside it is discharged.

[0104] Thereafter, an empty loading platform 65 is placed on the chassis 62, and the automated trolley 61 starts moving forward from the discharge position. The automated trolley 61 enters the roof pipe row 5, travels forward within the roof pipe row 5, and eventually reaches the standby position. There, the automated trolley 61 once again receives the soil and sand carried out from the conveyor 29 onto the loading platform 65.

[0105] While the automated cart 61 departs from the standby position and returns to the standby position (i.e., while the automated cart 61 travels back and forth between the standby position and the discharge position), the conveyor 29 is stopped, but excavation continues. This allows the excavation work to continue uninterrupted.

[0106] Next, the specific details of the excavation work (excavation step) will be described.

[0107] 13(A), (B) and 14 specifically show the operation of the excavation tool 26 etc. during excavation work. Before explaining the operation, a predetermined excavation area of ​​the natural ground G or the working face K will be explained.

[0108] Figure 19 is a rear view conceptually showing the excavation area of ​​the cutting face K. The leading roof pipe 93 is shown in phantom lines. The symbol A indicates the outer peripheral surface of the leading roof pipe 93, specifically the outer peripheral surface of the cutting edge 10, which is synonymous with the outermost edge of the front end face 18 of the cutting edge 10. Here, "outside" refers to the direction away from the pipe central axis C in the illustrated example. Conversely, "inside" refers to the direction approaching the pipe central axis C in the illustrated example.

[0109] The symbol B indicates the excavation area of ​​the face K. This excavation area B is divided into a main excavation area B1 inside the outer peripheral surface A and a surplus excavation area B2 outside the outer peripheral surface A. Excavating the main excavation area B1 is called main excavation, and excavating the surplus excavation area B2 is called surplus excavation.

[0110] The main reasons for performing such extra excavation are to reduce frictional resistance with the ground G when the roof pipe row 5 moves forward, and to enable the insertion of the joints 17 protruding from the outer circumferential surfaces of the roof pipes 3. The extra excavation area B2 has a width S that is large enough to allow for the insertion of the joints 17. The excavator 20 of this embodiment is configured to be able to efficiently excavate not only the main excavation area B1, but also the extra excavation area B2.

[0111] In the illustrated example, the size of the width S varies along the circumferential direction. At the position where the joint part 17 is present, the width S of the extra excavation region B2 is made larger than the width of the joint part 17. At the position where the joint part 17 is not present, the width S of the extra excavation region B2 is made smaller than the width of the joint part 17. This makes it possible to form the extra excavation region B2 with a width S that is necessary and sufficient for inserting the joint part 17.

[0112] Alternatively, the size of the width S may be constant along the circumferential direction, or may be a constant width S that is larger than the width of the joint portion 17.

[0113] Figures 13(A), (B) and 14 show the ideal shape of the face K after the main excavation and the extra excavation (collectively referred to as excavation) are completed. The imaginary line F indicates the boundary between the main excavation area B1 and the extra excavation area B2. After excavation is completed, the actual face shape will not necessarily be the ideal shape as shown, but excavation is carried out with this ideal shape as the target shape. The line for the extra excavation area B2 shown in Figure 19 also indicates a similar target shape.

[0114] The front-to-rear length of the excavation area B in one excavation operation, i.e., the excavation length, is L. For example, the excavation length L is about 25 cm if the soil quality of the ground G is good, and about 10 cm if it is poor. The shape of the working face K after excavation is completed in a side view (FIG. 13(A)) and a plan view (FIG. 15(A)) roughly matches the shape of the front end face 18 of the cutting edge 10 in a side view and a plan view.

[0115] The above-mentioned excavation step includes a main excavation step of excavating a main excavation area B1 and an extra excavation step of excavating an extra excavation area B2, and the extra excavation step is carried out simultaneously with or after the main excavation step.

[0116] As shown in FIG. 13(A), first, the forward / backward moving part 22 is advanced, and the excavation tool 26 is plunged deeper into the main excavation area B1 of the natural ground G.

[0117] Next, the undulating section 25 is rotated downward, and the natural ground G is scraped off by the excavation tool 26. As a result, most of the lower part of the main excavation area B1 is completely excavated. At this time, the excavation tool 26 is continuously moved from the main excavation area B1 to the lower remaining excavation area B2, and a portion of the front side of the remaining excavation area B2 is also partially excavated.

[0118] If only the derricking unit 25 were to rotate, the trajectory of the tip 59D of the excavation tool 26 would be arc-shaped, which would not match the dogleg-shaped final target shape of the face K. Therefore, the rotation of the derricking unit 25 and the forward and backward movement of the forward and backward moving unit 22 may be combined to obtain the final target shape of the face K.

[0119] Next, a portion of the upper side of the main excavation area B1 that was left unexcavated and a portion of the upper excess excavation area B2 that was left unexcavated are excavated. At this time, the excavation tool 26 is returned to its initial position (the position in the initial state, see Figure 12), and the excavation tool 26 is temporarily pulled out of the natural ground G. Then, the upward rotation of the tool attachment part 98 and the forward movement of the front-rear moving part 22 are combined, and the excavation tool 26 is gradually rotated upward and inserted into the natural ground G. Finally, the tip 59D of the excavation tool 26 is positioned at the frontmost and upper corner of the upper excess excavation area B2. From this state, the tool attachment part 98 and the excavation tool 26 are both rotated downward (i.e., swiveled), and a portion of the front side of the upper excess excavation area B2 and a portion of the upper side of the main excavation area B1 that was left unexcavated are scraped away.

[0120] At this time, the excavation tool 26 may be rotated downward by rotating the hoisting unit 25 in combination with the rotation of the hoisting unit 25 or by rotating the hoisting unit 25 alone.

[0121] Although an example has been described in which the entire excavation length L is excavated by a single rotation of the excavation tool 26, it is of course also possible to repeatedly excavate portions of the excavation length L by multiple rotations of the excavation tool 26. The same applies to the following explanation.

[0122] Next, as shown in Figure 13(B), the remaining portions of the upper main excavation area B1 and the remaining excavation area B2 are excavated. At this time, the excavation tool 26 is returned to its initial position, the rotating unit 24 is rotated 180°, and the excavation tool 26 is turned upside down. Then, the forward / backward moving unit 22 is moved forward, and the tool mounting unit 98 is rotated upward, so that the excavation tool 26 is bent upward as shown by the imaginary line. That is, the excavation tool 26 is in a state in which the tip 59D faces upward and the open portion 59F faces backward.

[0123] At the start of digging, the tip 59D of the excavating tool 26 is positioned at the front and upper corner of the upper remaining excavation area B2. From this state, the forward / backward moving unit 22 is retracted, and the excavating tool 26 is translated backward. This excavates and scrapes off the remaining upper excavation area.

[0124] Next, as shown in Figure 14, the remaining portions of the lower main excavation area B1 and the remaining excavation area B2 are excavated. At this time, the excavation tool 26 is temporarily returned to its initial position. Thereafter, the forward / backward moving unit 22 is advanced, the hoisting unit 25 is rotated downward, and the tool mounting unit 98 is rotated downward. As a result, the excavation tool 26 is bent downward as shown by the imaginary lines. That is, the excavation tool 26 is in a state in which the tip 59D faces downward and the open portion 59F faces backward.

[0125] At the start of digging, the tip 59D of the excavating tool 26 is positioned at the front and bottom corner of the lower remaining excavation area B2. From this state, the forward / backward moving part 22 is retracted, and the excavating tool 26 is translated backward. This excavates and scrapes out the remaining portion below.

[0126] By the operation of this excavation tool 26, the soil and sand accumulated at the bottom of excavation area B is scraped off by excavation tool 26 and carried onto conveyor 29. Note that even when not excavating the remaining lower portion, excavation tool 26 is moved backward at the bottom of excavation area B as appropriate and is used to transfer the soil and sand accumulated at the bottom of excavation area B to conveyor 29.

[0127] The above-mentioned excavation method is an example, and various other excavation methods are also possible.

[0128] The above-described excavation operation is performed when the excavation tool 26 is located in one position in the left-right direction, i.e., in the center, as shown by the solid line in Figure 15(A). In this case, excavation can only be performed in the left-right center.

[0129] 15(A), when excavating another position in the left-right direction, excavation tool 26 is rotated left-right by rotating swivel part 23, thereby changing the left-right position of excavation tool 26. This allows excavation at other positions to be carried out without any problems.

[0130] In the illustrated example, the excavation tool 26 has a rectangular shape with its tip 59D facing forward and its open portion 59F facing downward. The excavation area B has a horizontally elongated rectangular shape with a width greater than its front-to-rear width and a width greater than that of the leading roof pipe 93. When the excavation tool 26 is pivoted to the far right as shown in the illustration, the excavation tool 26 is inserted into the remaining excavation area B2 on the right side, but small triangular first and second unexcavated areas M1 and M2 are created in front of and to the right of the excavation tool 26. The same is true on the left side.

[0131] The first unexcavated area M1 includes the front and rightmost corner of the right-side remaining excavated area B2, and the second unexcavated area M2 includes the rear and rightmost corner of the right-side remaining excavated area B2.

[0132] Therefore, in this embodiment, the first and second triangular unexcavated areas M1 and M2 are excavated as much as possible by the operation shown in Figure 15(B). The operations on the right and left sides are similar except for the fact that they are symmetrical, so only the right side will be explained below.

[0133] As shown in Figure 15(B), excavation tool 26 is temporarily returned to its initial position. Then, forward / backward moving unit 22 is moved forward, rotating unit 24 is rotated 90° counterclockwise as viewed from the rear, and tool mounting unit 98 is rotated rightward (sideways). As a result, excavation tool 26 is bent rightward (sideways) as shown by the imaginary line. That is, excavation tool 26 is in a state in which tip 59D faces right and open portion 59F faces backward.

[0134] By the above operation, tip 59D of excavation tool 26 is positioned at the front-most right corner of right-side remaining excavation area B2. Prior to being positioned here, the triangular first unexcavated area M1 in front of excavation tool 26 has been excavated.

[0135] Thereafter, the forward / backward moving unit 22 is retracted, and the excavation tool 26 is translated backward, whereby the triangular second unexcavated area M2 on the right side (side) of the excavation tool 26 is excavated.

[0136] During excavation work as shown in Figures 13 to 15, soil and sand accumulate inside the cutting edge 10 and at the bottom of the excavation area B. This soil and sand is scraped off by the excavation tool 26 and placed on the carry-in end located at the front end of the conveyor 29. The soil and sand is then transported to the carry-out end located at the rear end of the conveyor 29, and from the carry-out end it is dispensed onto the automated cart 61 which is in a standby position. In this way, the accumulated soil and sand is transferred to the automated cart 61 in a timely manner, which prevents the accumulated soil and sand from deteriorating the excavation workability.

[0137] When the load of soil on the automated cart 61 reaches a predetermined upper limit, the automated cart 61 is moved backward to the outside behind the roof pipe row 5. After being emptied outside, the automated cart 61 moves forward and returns to the standby position. While the automated cart 61 starts from the standby position and returns, the conveyor 29 is temporarily stopped, but excavation continues. This allows excavation work to continue uninterrupted.

[0138] When the excavation work is completed as described above, the excavation tool 26 is stored inside the cutting edge 10, as shown in Figure 16(A). At this time, the forward / backward moving part 22 is positioned at the rearmost position, the undulating part 25 faces diagonally downward, and the excavation tool 26 is positioned facing downward.

[0139] 16(B), the roof pipe row 5 is pushed out from the rear by a pipe insertion jack (not shown), and the roof pipe row 5 is advanced by the excavation length L. This brings the front end face 18 of the cutting edge 10 into contact with or close to the face K newly created by excavation.

[0140] At this time, a space 67 is formed outside the front end of the cutting edge 10 due to excess excavation, but this space 67 will be filled later with a filler such as a hardenable lubricant.

[0141] Next, the main features of this embodiment will be described.

[0142] <First feature> This embodiment includes a fixing step of fixing the above-described excavator 20 inside the leading roof pipe 93, and an excavation step of excavating the natural ground G located in front of the leading roof pipe 93 with the excavator 20. This eliminates the need to perform the excavation work manually, making the excavation work easier.

[0143] The excavator 20 is equipped with a movable forward / backward moving section 22, a swivel section 23, a rotating section 24, a raising / lowering section 25, and an implement mounting section 98. Therefore, the position and orientation of the excavation implement 26 can be changed relatively freely even within the narrow leading roof pipe 93, and the ground G can be excavated without any omissions.

[0144] The excavation step includes a main excavation step of excavating a portion of the natural ground G located in the main excavation area B1. Therefore, the main excavation area B1, which is the minimum area required for the roof pipe row 5 to advance, can be efficiently excavated by the excavator 20.

[0145] The excavation tool 26 includes a shovel 26A. Therefore, the excavation tool 26 can be used not only for digging but also for transporting excavated soil and sand.

[0146] The excavation implement 26 is removably and replaceably mounted to the implement mounting portion 98. Therefore, if the excavation implement 26 is damaged, it can be easily repaired or replaced.

[0147] <Second feature> The excavation step includes an extra excavation step of excavating a portion of the natural ground G located in the extra excavation area B2. Therefore, even if the joint portion 17 is provided on the outer circumferential surface of the roof pipe 3 and extra excavation is required, this can be carried out efficiently by the excavator 20.

[0148] In this embodiment, for example, as shown in Figure 13, the extra excavation step is performed simultaneously with the main excavation step. This allows the extra excavation and main excavation to be performed simultaneously, allowing the excavation work to be carried out efficiently. However, the extra excavation step may also be performed after the main excavation step. Since most of the excavation area B has been excavated in the main excavation, the extra excavation is easy.

[0149] <Third feature> The excavation step includes a transport step in which the soil excavated by the excavation tool 26 is transported by the conveyor 29 to the rear end of the excavator 20; a loading step in which the soil transported by the conveyor 29 is loaded onto an automatic cart 61 that is waiting in advance at a standby position; a transport and discharge step in which the automatic cart 61 loaded with the soil is driven to the outside through the rear end opening of the roof pipe row 5 and the soil is discharged from the automatic cart 61; and a return step in which the automatic cart 61 from which the soil has been discharged is driven into the roof pipe row 5 through the rear end opening of the roof pipe row 5 and returned to the standby position again.

[0150] Therefore, even if earth and sand accumulates inside the cutting edge 10 or at the bottom of the excavation area B during excavation work, the amount of accumulation can be kept small, preventing the excavation workability from being deteriorated by the accumulated earth and sand.

[0151] Furthermore, when the automated cart 61 becomes full of earth and sand, the automated cart 61 is driven to the outside to discharge the earth and sand, and the emptied automated cart 61 can be returned to the standby position. This process is repeated when the automated cart 61 becomes full of earth and sand again. Therefore, earth and sand generated during excavation work can be discharged to the outside as needed, improving workability.

[0152] The transport step includes loading the soil and sand onto the conveyor 29 by the excavation tool 26. This allows the soil and sand accumulated inside the cutting edge 10 and at the bottom of the excavation area B to be efficiently transferred to the conveyor 29.

[0153] During the period from when the automated cart 61 departs from the standby position in the discharge step to when the automated cart 61 returns to the standby position in the return step, the conveyor 29 is temporarily stopped, while the excavator 20 continues excavating. This allows the excavation work to continue uninterrupted, improving work efficiency.

[0154] <Fourth feature> The front and rear wheel sections 31F, 31R of the excavator 20 can pass through the gaps 13 between the flanges 12 provided on the lower left and right sides of the roof pipe 3. Therefore, the wheel sections 31F, 31R can travel on the floor surface 93A inside the roof pipe 3 without being obstructed by the flanges 12, and the wheel sections 31F, 31R, and therefore the excavator 20, can pass over the flanges 12 and flange connections while traveling.

[0155] The excavator 20 can move in and out between the inside and outside of the roof pipe row 5 through the rear end opening of the roof pipe row 5 by traveling on the wheel sections 31F, 31R. Therefore, if an obstacle is found in the natural ground G or the excavator 20 breaks down and it becomes necessary to remove the excavator 20 from inside the roof pipe row 5, this can be easily done by moving the excavator 20 backward. Furthermore, when the situation is resolved, the excavator 20 can be moved forward and easily returned to its original position.

[0156] The excavator 20 has anti-tip mechanisms 43 on both the left and right sides thereof for preventing the excavator 20 from tipping over in the left and right direction. This makes it possible to reliably prevent the excavator 20 from tipping over in the left and right direction. The anti-tip mechanisms 43 can pass through the gaps 13 between the upper and lower flanges 12 on both the left and right sides. This makes it possible to prevent the travel of the excavator 20 from being obstructed by those flanges 12.

[0157] Furthermore, the existence of the left and right anti-tip mechanisms 43 allows the excavator 20 to travel while always being guided to the left and right center of the roof pipe 3 (centering function). The left and right positions of the wheel sections 31F, 31R can be maintained at a predetermined position equal to the gap 13. This prevents the excavator 20 from bending while traveling, and allows the excavator 20 to pass through the flange 12 reliably.

[0158] <5th feature> The fixing part 21 has a fixing mechanism 30 that fixes the fixing part 21 by tensioning it between the floor surface 93A and ceiling surface 93B of the leading roof pipe 93. This allows the fixing part 21 to be reliably fixed inside the leading roof pipe 93. In particular, the space inside the leading roof pipe 93 is narrow, and the height dimension from the floor surface 93A to the ceiling surface 93B is relatively small. For this reason, the fixing mechanism 30 of this embodiment, which fixes by tensioning it, is ideal for this construction method.

[0159] The fixing mechanism 30 has telescopic tubes 33 that can be extended and retracted in the vertical direction, and a fixing cylinder 34 that extends and retracts the telescopic tubes 33. In the fixing mechanism 30 of this embodiment, multiple telescopic tubes 33 (front and rear telescopic tubes 33 on the left and right sides) are connected by connecting members 35, and the fixing cylinder 34 extends and retracts the multiple telescopic tubes 33 simultaneously by raising and lowering the connecting members 35. This eliminates the need to provide individual fixing cylinders 34 for the multiple telescopic tubes 33, thereby reducing the number of parts and manufacturing costs.

[0160] [Second embodiment] Next, a second embodiment of the present disclosure will be described. Note that a description of the same parts as in the first embodiment will be omitted, and the following description will mainly focus on the differences from the first embodiment.

[0161] In this embodiment, digging tool 26 is different from that in the first embodiment. In the first embodiment, digging tool 26 includes a shovel 26A as shown in FIG. 7. In contrast, in this embodiment, digging tool 26 includes an assembly of a chipper 68 and a blade 69, i.e., a chipper assembly 70, as shown in FIG. 20. Excavating tool 26 of this embodiment includes a first type of digging tool made up of chipper assembly 70.

[0162] In Figure 20, (A) is a plan view, and (B) is a side view (XXB-XXB cross-sectional view of (A)). As in Figure 7, the front-to-back, left-to-right, up-to-down directions shown in (B) are determined for the sake of convenience in explaining the positional relationships of the various parts, and it should be noted that they have no direct relationship to the directions of the roof pipe 3, the excavator 20, etc. shown in Figure 21, etc.

[0163] The excavation tool 26 of this embodiment uses a chipper 68 to chip and excavate the natural ground, and a blade 69 to scrape, rake, and scoop up the excavated soil. In other words, the functions of the shovel 26A of the first embodiment are shared between the chipper 68 and the blade 69. As is well known, the chipper 68 is also called a concrete hammer, and is a hydraulic, pneumatic, or electric tool that axially vibrates a chipping bar 71 inserted into the natural ground to continuously strike the ground and excavate or crush it. The chipping bar 71 of this embodiment is a bull point with a sharp tip, but it may also be a chisel with a flat, chisel-like tip. The chipper 68 is particularly useful when the natural ground G is hard.

[0164] Excavation tool 26 has a support member 72 that forms its base end or rear end and serves as an attachment portion to tool attachment bracket 55. Support member 72 is formed in a crank shape in side view and has a chipper attachment portion 72A that extends in the vertical direction, an extension portion 72B that extends forward from the lower end of chipper attachment portion 72A, and a blade attachment portion 72C that extends downward from the front end of extension portion 72B.

[0165] The chipper 68 extends from the rear to the front, and its rear end is attached to the chipper attachment part 72A, with its tip (tip of the chipping bar 71) 73 facing forward.

[0166] The blade 69 extends vertically and horizontally and is disposed approximately perpendicular to the longitudinal direction of the chipper 68. The upper half of the blade 69 is attached to the front of the blade attachment portion 72C in a stacked manner. A central portion 69A of the blade 69 in the left-right direction is parallel to the left-right direction, and both end portions 69B are bent diagonally rearward relative to the central portion 69A. This allows the central portion 69A and both end portions 69B of the blade 69 to function similarly to the bottom plate 59A and left and right side plates 59E of the shovel 26A shown in FIG. 7. The rear side of the blade 69 is an open portion 69C that receives soil and sand.

[0167] The blade 69 of this embodiment has lower rigidity than the shovel blade 59, and does not have enough rigidity to directly excavate the unexcavated natural ground G.

[0168] The chipper 68 and the blade 69 are arranged so as to be substantially perpendicular to each other, and the chipper 68 protrudes forward more than the blade 69 when the blade 69 faces downward.

[0169] Figures 21 and 22 are a side view and a plan view of the excavator 20 of this embodiment, corresponding to Figures 3 and 4. In the basic position shown in Figure 21, the excavating tool 26 is positioned so that the tip 73 of the chipper 68 faces downward and the open portion 69C of the blade 69 faces upward. On the other hand, for convenience, Figure 22 shows the excavating tool 26 in a position rotated approximately 90° upward from the basic position. At this time, the tip 73 of the chipper 68 faces forward and the open portion 69C of the blade 69 faces rearward.

[0170] Figures 23(A) and 23(B) show the operation of the excavator 20 of this embodiment, which corresponds to Figures 13(A), 13(B), and 14. This operation is generally similar to that of the first embodiment. However, in this embodiment, the chipper 68 is made as perpendicular as possible to the natural ground G, and in this state the chipper 68 is pushed into the natural ground G to perform excavation. After excavation, the chipper 68 is then pulled out of the natural ground G, completing one cycle of excavation by pushing and pulling. One cycle of excavation is repeated successively at different positions. Therefore, this is different from the operation of continuously scraping and scraping off the natural ground G as in the first embodiment.

[0171] In the example shown in Figure 23(A), similar to the examples shown in Figures 13(A) and 14, the chipper 68 excavates a height range from the frontmost and upper corner of the upper remaining excavation area B2 to the rearmost and lower corner of the lower remaining excavation area B2 using the front and rear movement of the front-to-rear moving section 22 and the rotation of the raising and lowering section 25 and the tool mounting section 98.

[0172] 23(B), similarly to the example shown in Fig. 13(B), the upper remaining excavation area B2 is excavated using the rotation of the rotating part 24, the rotation of the tool attachment part 98, and the forward and backward movement of the forward and backward movement part 22. At this time, the excavation tool 26 is placed in a state in which the tip 73 faces obliquely upward and forward, and the open part 69C faces obliquely downward and rearward.

[0173] In this embodiment, after excavation is completed, a predetermined advance excavation portion 74 is formed at the lower end of the working face K. This advance excavation portion 74 is a portion where earth and sand remain after only loosening (softening) the natural ground G. This will be described later.

[0174] Figures 24(A) and 24(B) show the operation of the excavator 20 of this embodiment corresponding to Figures 15(A) and 15(B). This operation is also generally similar to that of the first embodiment.

[0175] In the example shown in FIG. 24(A), as in the example shown in FIG. 15(A), the excavating tool 26 is rotated left and right by rotating the swivel unit 23, changing the excavation position. However, in this embodiment, because the blade 69 interferes with the cutting edge 10, it is not possible to excavate as much of the left and right end portions by rotation alone as in the first embodiment. Therefore, as shown in FIG. 24(B), the excavating tool 26 is rotated 90° by using the rotation of the rotating unit 24. This moves the blade 6 further toward the pipe center axis C, eliminating interference between the blade 6 and the cutting edge 10, allowing the remaining portion in the example shown in FIG. 24(A) to be excavated without any problems.

[0176] Incidentally, even when excavating the four corners of the excavation area B, the rotation of the rotating part 24 can be used to eliminate interference with the cutting edge 10 of the blade 6.

[0177] 15(B), left and right remaining excavation areas B2 are excavated using the rotation of the rotating unit 24, the rotation of the tool attachment unit 98, and the forward and backward movement of the forward and backward movement unit 22. When excavating the right side, the excavation tool 26 is positioned so that the tip 73 faces diagonally forward to the right and the open portion 69C faces diagonally backward to the left, and when excavating the left side, the tip 73 faces diagonally forward to the left and the open portion 69C faces diagonally backward to the right.

[0178] Now, when the excavation work in excavation area B is completed as described above, next, as shown in Figure 25, preliminary excavation is carried out to excavate a predetermined preliminary excavation section 74. This preliminary excavation is carried out so that the excavated earth and sand can be transferred to the conveyor 29 by the blade 69. The preliminary excavation section 74 is positioned at the front of the lower part of excavation area B.

[0179] The soil and sand that has accumulated at the bottom of excavation area B and cutting edge 10 due to the excavation of excavation area B is scraped off by moving blade 69, with open section 69C facing rearward, backward as forward / backward moving section 22 retreats, as shown by the imaginary lines in the figure, and is transported to the carrying-in end of conveyor 29. However, if advance excavation is not performed at this time, chipper 68 protruding forward from blade 69 will interfere with face K, and blade 69 cannot be positioned at the front end of excavation area B.

[0180] Therefore, prior to scraping by the blade 69, preliminary excavation is carried out. At this time, the chipper 68, with its tip 73 facing forward, chips and loosens the ground G in the preliminary excavation section 74. The loosened soil is left in the preliminary excavation section 74. This allows the chipper 68 to plunge into the loosened soil, positioning the blade 69 at the front end of the excavation area B. The blade 69 is then moved rearward from that position, and the soil from the front end to the rear end is scraped off and transferred to the conveyor 29. Once almost all of the soil has been transferred in this way, the excavation work (excavation step) is completed.

[0181] At this time, the undulating portion 25 is rotated downward, and the blade 69 is positioned at the bottom of the excavation area B. In the illustrated example, a pre-excavation portion 74 having a U-shaped cross section is formed over the height range of the lower front end face 18B of the cutting edge 10, but the height range and cross-sectional shape of the pre-excavation portion 74 are arbitrary.

[0182] After this, the same operations as those shown in Figures 16(A) and (B) are performed. That is, as shown in Figure 26(A), the excavation tool 26 is stored inside the cutting edge 10. At this time, the forward / backward moving section 22 is positioned at the rearmost position, the undulating section 25 faces diagonally downward, and the excavation tool 26 is positioned so that the tip 73 of the chipper 68 faces downward. Thereafter, as shown in Figure 26(B), the roof pipe row 5 is advanced. At this time, the preceding excavation section 74 has already completed excavation, and in this sense the term "preceding excavation" is used.

[0183] It will be understood that if excavation of excavation area B is carried out again from this state, a portion of the front end of the preceding excavation section 74 will remain when excavation of excavation area B is completed, as shown in Figure 23(A).

[0184] This embodiment can also achieve the same effects as the first embodiment.

[0185] Next, a modified example will be described.

[0186] In this modified example, the digging tool 26 includes the chipper assembly 70 of this embodiment and the shovel 26A of the first embodiment. These are interchangeable as needed. That is, in this modified example, the digging tool 26 includes a first type of digging tool consisting of the chipper assembly 70 and a second type of digging tool consisting of the shovel 26A. The digging tool 26 is detachably attached to the tool attachment portion 98, and the first type of digging tool and the second type of digging tool are interchangeable.

[0187] This makes it possible to select the optimum excavation tool 26 depending on the soil quality of the ground G, thereby improving excavation efficiency. Furthermore, when the excavation tool 26 needs to be replaced due to a change in soil quality during construction, the excavator 20 can be temporarily removed outside the roof pipe row 5, so that the replacement work can be easily carried out in the large space outside the roof pipe row 5.

[0188] Although the embodiments of the present disclosure have been described in detail above, various other embodiments and modifications of the present disclosure are possible.

[0189] For example, if the excavator 20 can travel sufficiently independently, the anti-tip mechanism 43 may be omitted.

[0190] The embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications, applications, and equivalents encompassed within the spirit of the present disclosure as defined by the claims are included in the present disclosure. Therefore, the present disclosure should not be interpreted as being limited, and can be applied to any other technology that falls within the spirit of the present disclosure. [Explanation of symbols]

[0191] 2 box 3 roof pipe 4 Box roof 5 Roof pipe row 10 Blade mouth 11 Pipe body 12 flange 13 Gap 17 Joint 20 Excavator 21 Fixed part 22 Forward / backward moving section 23 Swivel section 24 Rotating part 25 Relief 26 Excavation equipment 26A Shovel 29 Conveyor 30 Fixing mechanism 31F,31R Wheel part 33 Telescopic tube 34 Fixing cylinder 35 Connecting member 43 Anti-tip mechanism 61 Automatic trolley 68 Chipper 69 Earth removal plate 70 Chipper Assembly 74 Advance Excavation Section 93 Front roof pipe 93A Floor 93B Ceiling surface 98 Equipment mounting part B Excavation area B1 Main excavation area B2 Excavation area C1 1st axis C2 2nd axis C3 3rd axis C4 4th axis G mountain

Claims

1. A trenchless jacking method in which a box-shaped roof formed by a plurality of roof pipes and buried in the ground is replaced with a box body, and the box body is buried in the ground, The box-shaped roof is configured by arranging a row of roof pipes, each row being formed by connecting a plurality of the roof pipes in series, in parallel along the outer edge of the box body, The non-excavation jacking method is a fixing step of fixing an excavator within the leading roof pipe of the row of roof pipes; an excavation step of excavating the natural ground located in front of the leading roof pipe by the excavator; a propelling step of advancing the row of roof pipes after excavation by the excavator; Equipped with The excavator is a fixing part that can travel inside the roof pipe and be fixed inside the leading roof pipe; a forward / backward moving unit provided on the fixed unit so as to be movable in a forward / backward direction relative to the fixed unit; a swivel unit provided on the front-rear moving unit so as to be rotatable about a first axis extending in a vertical direction relative to the front-rear moving unit; a rotating portion provided on the turning portion so as to be rotatable about a second axis extending in the front-rear direction relative to the turning portion; an undulating portion provided on the rotating portion so as to be rotatable about a third axis extending in the left-right direction relative to the rotating portion; an instrument mounting portion provided on the undulating portion so as to be rotatable about a fourth axis extending in the left-right direction relative to the undulating portion; a drilling tool attached to the tool attachment portion; Equipped with The fixing portion has a fixing mechanism that can fix the fixing portion by being stretched between the floor surface and the ceiling surface of the leading roof pipe. A trenchless jacking method characterized by:

2. The fixing mechanism includes an extension tube that can be extended and retracted in the vertical direction, and a fixing cylinder that extends and retracts the extension tube. The trenchless jacking method according to claim 1.

3. The plurality of telescopic tubes are connected by a connecting member, and the fixing cylinder moves the connecting member up and down to simultaneously extend and retract the plurality of telescopic tubes. The trenchless jacking method according to claim 2.

4. The pair of front and rear telescopic tubes, the connecting member connecting the pair of front and rear telescopic tubes, and the fixing cylinder are provided on both the left and right sides of the fixing part. The trenchless jacking method according to claim 3.

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