JP2005163365A - Jacking method for tunnel lining rectangular steel pipe, and tunnel lining rectangular steel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly and rapidly jack a rectangular steel pipe with small thrust while preventing consolidation of excavated sediment to the natural ground due to a projecting joint of the rectangular steel pipe and positively suppressing the deformation of the rectangular steel pipe and the deformation of the earth surface. <P>SOLUTION: The rectangular steel pipe 1 is provided with a first bit 8 provided at the tip outer periphery of a cutting edge 1B, in a position near the projecting joint 7 in the cross-sectional view of the rectangular steel pipe 1 to take in the excavated sediment into the cutting edge 1B and having a cross-sectional area larger than the cross section of the projecting joint 7; a second bit 9 provided at the outer periphery of the cutting edge 1B behind the first bit 8 being shifted in position from the first bit 8 so as to partially overlap one predetermined region of the projecting joint 7 in the cross-sectional view, and having a cross-sectional area smaller than the first bit 8; and a third bit 10 provided at the outer periphery of the cutting edge 1B behind the second bit 9 being shifted in position from the second bit 9 so as to partially overlap the other predetermined region of the projecting joint 7 in the cross-sectional view of the rectangular steel pipe 1. The projecting joint 7 is arranged behind the third bit 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for propelling a tunnel lining square steel pipe and a square lining steel pipe for tunnel lining that are used, for example, when constructing a three-dimensionally intersecting tunnel under a railway or a road.

Conventionally, as a method of constructing a three-dimensionally intersecting tunnel under a railway or road, a long square steel pipe (element for tunnel lining) is horizontally propelled to a natural ground by a digging device installed behind it, And excavating the earth and sand of the ground with the cutter of the excavation element provided at the tip, and excavating while excavating the excavated earth and sand through the square steel pipe, the multiple square steel pipes are sequentially turned into the tunnel gate shape. The tunnel lining body is made by penetrating and burying in the ground along the cross section of the arch, circle, rectangle, etc., filling the concrete in the square steel pipe and between the adjacent square steel pipes and hardening it. Is constructed, and after that, excavation and removal of the soil inside the tunnel lining body is known.
And the square steel pipe which comprises the said tunnel lining body is provided with the joint part for joining with the square steel pipe adjacent on the upper and lower sides in the both sides. This joint is provided so as to project vertically above and below one side of the square steel pipe, and is a male mold that is fitted into a female joint (projection joint) of a square steel pipe that was previously embedded in a natural ground. A joint (protruding joint) and a male joint on one side of a square steel pipe that is provided along the longitudinal direction of the other side of the square steel pipe along the longitudinal direction and projecting to the side and then embedded are fitted. It is set as the structure provided with the female type | mold joint (for example, refer patent document 1).
Japanese Unexamined Patent Publication No. 7-62969

In the above conventional tunnel construction method, after cutting a natural ground with a cutter that rotates at the center of the tip of the square steel pipe and excavates the face, the cutting edge of the tip of the square steel pipe is cut into the cutter. The square steel pipe corresponding to the four corners of the square steel pipe that was not excavated in the crushing is crushed, and the crushed earth and sand is transferred to the cavity formed by the cutter to dig the square steel pipe into the ground. However, as described above, the female joint provided on the square steel pipe so as to project laterally above and below the other side part exists as a projecting part projecting outward at the upper and lower corners of the square steel pipe. Therefore, even if the tip of the female joint is sharply sharpened and propelled into the soil, the earth and sand pushed away by the female joint is consolidated into the surrounding natural ground of the female joint, thereby As the earth pressure increases, the excavator needs a large thrust, and the square steel pipe Leading to a situation in which the cause until the deformation and surface deformation.
In particular, when the female joint is a tip-enlarged one having a stem portion or is attached so as to be far away from the steel pipe side to the outer side at the corner of the square steel pipe, that is, As the distance from the cross section of the face to the tip position of the female joint increases, the soil that replaces the female joint (excluded by the female joint) loses its escape and is consolidated into the surrounding ground. There is a problem that such a situation is more likely to occur.

  The present invention has been made in view of the above circumstances, and by effectively moving the excavated sediment of the natural ground corresponding to the projecting joint generated along with the propulsion of the square steel pipe, the natural ground of the excavated sediment Can prevent the consolidation of the steel tube, reduce the propulsive force for the square steel pipe, and reliably suppress the deformation of the square steel pipe and the deformation of the ground surface, and can smoothly and quickly propel the square steel pipe for tunnel lining. It is an object of the present invention to provide a method for propelling a square steel pipe for tunnel lining and a square steel pipe for tunnel lining.

The present invention is characterized by the following points in order to solve the above problems.
That is, the propulsion method of the square steel pipe for tunnel lining according to claim 1 is along the cross section of the tunnel in which a plurality of square steel pipes provided with fixed projecting joints along the longitudinal direction on the outer periphery are to be constructed. In the propulsion method for a square steel pipe, which is constructed by sequentially propelling and burying in a natural ground, and connecting adjacent square steel pipes whose outer peripheral portions are opposed to each other via the projecting joint, the corner A plurality of bits are attached to the outer periphery of the cutting edge of the shaped steel pipe while shifting the position in the direction perpendicular to the propulsion direction of the square steel pipe and the direction perpendicular to the propulsion direction. The sand drilled by the tip bit at the front end is taken into the inside of the blade, and the sand drilled by the next bit following the tip bit is moved into the cavity formed by the tip bit, and the subsequent bits are sequentially drilled. A bit preceding the earth and sand Accordingly, the square steel pipe is propelled while being moved into the formed cavity, and after the excavation by the final bit, a cavity including at least a majority of the cross section of the protruding joint in a cross-sectional view of the square steel pipe is formed. .

  The square steel pipe for tunnel lining according to claim 2 has a projecting joint fixed along the longitudinal direction at the outer peripheral part, is pushed and buried in a natural ground to be constructed, and is adjacent to the outer peripheral part facing each other. A square steel pipe that constitutes a tunnel lining by being connected via the protruding joint, the square steel pipe being the outer periphery of the tip of the edge, and a cross section of the square steel pipe A first bit having a cross-sectional area larger than the cross section of the projecting joint, which is provided near the projecting joint as viewed, excavating a natural ground and taking earth and sand into the blade mouth, and a blade edge behind the first bit A second cross-sectional area smaller than the first bit provided on the outer periphery of the first bit so as to partially overlap a predetermined region of the protruding joint in a cross-sectional view of the square steel pipe. A bit and a cutting edge behind the second bit A second bit and a third bit shifted in position so as to partially overlap another predetermined region of the protruding joint in a cross-sectional view of the square steel pipe, the protruding joint being a third It is arranged behind the bit.

  The square steel pipe for tunnel lining according to claim 3 is the square steel pipe for tunnel lining according to claim 2, wherein the first bit has a tapered wedge shape with a surface facing the inside of the blade edge being an inclined surface. The wedge-shaped bit is formed in such a manner that the tip portion protrudes forward from the tip of the blade edge and is fixed to the blade edge.

  The square steel pipe for tunnel lining according to claim 4 is the square steel pipe for tunnel lining according to claim 2, wherein the first bit is composed of a rotating bit rotated by a driving means, and a rear side of the rotating bit. An opening for taking excavated earth and sand by a rotating bit into the blade is provided on the side wall of the blade.

  The square steel pipe for tunnel lining according to claim 5 is a square steel pipe for tunnel lining according to any one of claims 2 to 4, wherein a tip of the protruding joint is formed into a wedge-shaped bit capable of excavating a natural ground. It is characterized by being.

The present invention has the following excellent effects.
According to the propulsion method of a square steel pipe for tunnel lining according to claim 1, the excavation soil of the natural ground by the first bit among the plurality of bits provided by shifting the position on the outer periphery of the edge of the square steel pipe is provided. After taking in the blade, the square steel pipe is moved while moving the excavated earth and sand generated by excavating the ground part where the following bit does not overlap with the preceding bit into the cavity formed behind the preceding bit. Since it is possible to form a cavity in the natural ground portion where at least a majority of the cross section of the protruding joint provided protruding from the outer periphery of the square steel pipe is inserted, the amount of natural ground to be newly drilled by each bit can be reduced. While it can be reduced, even when the protruding joint protrudes greatly from the corner of the square steel pipe to the outside, the protruding joint penetrates into the natural ground and the amount of the natural ground portion to be newly excavated can be reduced. it can.
Therefore, it is possible to reliably prevent the deformation of the ground surface by each bit or protruding joint compacting the surrounding natural ground portion, and to reduce the thrust required for propulsion of the square steel pipe as much as possible. Thus, the square steel pipe can be propelled smoothly and quickly while suppressing the deformation.

  According to the square steel pipe for tunnel lining according to claim 2, the square steel pipe is propelled by providing a plurality of bits at the cutting edge of the square steel pipe with the positions shifted in the propulsion direction and the cross-sectional direction of the square steel pipe. Since the space which inserts at least the majority part of the protrusion joint attached to the outer periphery of a square steel pipe sometimes can be formed reliably, the propulsion method of the square steel pipe for tunnel lining according to claim 1 is surely realized. Moreover, the structure is simple and can be implemented easily.

  According to the square steel pipe for tunnel lining according to claim 3, the structure of the first bit is simple, and the ground is easily collided with the wedge-shaped blade surface by the promotion of the square steel pipe, and the excavated earth and sand are put into the blade edge. Can be reliably captured.

  According to the square steel pipe for tunnel lining according to claim 4, even when the square steel pipe hits a hard soil ground, it can be easily excavated by the rotating bit, and the excavated earth and sand can be It can take in from the opening part of the side wall of the inside of a blade edge.

  According to the square steel pipe for tunnel lining according to claim 5, even if there is a ground part that is not excavated by the first and second bits preceding the traveling destination, the protruding joint has the ground part itself. It can be easily excavated with a wedge-shaped bit.

Hereinafter, a square steel pipe for tunnel lining according to an embodiment of the present invention will be described with reference to the accompanying drawings.
In the figure, 1 is a square steel pipe for tunnel lining according to one embodiment of the present invention. The square steel pipe (square steel pipe) 1 for tunnel lining is shown in FIG. The outer plate 2 and the lower inner plate 3 are joined by both side plates 4 and 5 to form a long cylindrical body having a rectangular cross section (cross section). Are fixed by male joints (protruding joints) 6 and 6 each having a rectangular cross-section projecting outward (up and down in FIG. 1) along the side edge of one of them (left side in FIG. 1). Female joints (projecting joints) 7 and 7 are fixedly provided along the other side edge (right side in FIG. 1). Each of the female joints 7 and 7 has a grooved portion 7b, which is an enlarged portion, integrally joined to the tip of a support piece (stem portion) 7a, and has a cross-sectional shape formed in the shape of the grooved portion 7b. The groove 7c sides of each other face each other, and the groove mold portion 7b protrudes outward (right side in FIG. 1) from the wall surface of the side plate (the other side plate) 5 so that the outer part is interposed through the support piece portion 7a. The plate 2 and the inner plate 3 are fixed. And it fits to the male joints 6, 6 provided on the outer plates 2, 3 of one side edge of the square steel pipe 1 adjacent to the grooves 7 c, 7 c of the female joints 7, 7. It has become.

Further, as shown in FIGS. 2, 3, and 8, the square steel pipe 1 includes a long square steel pipe main body 1A and a short blade 1B that is detachably connected to the tip thereof.
On the outer periphery of the cutting edge 1B, the first bit 8 is positioned at the upper side and the lower side of the side plate 5 on the other side (the side where the female joint 6 is located) at a position on the leading side in the propulsion direction of the square steel pipe 1. 8 is provided with a second bit 9, 9 fixed at a position spaced apart from the first bit 8, 8 on the rear side (opposite to the propulsion direction of the square steel pipe 1), The third bit 10 is positioned behind the second bit 9 at a predetermined interval, and on the other side of the outer plate 2 and the inner plate 3 (lower side in FIG. 2, right side in FIGS. 4 to 7). 10 is fixedly provided (the inner plate 3 side is not shown in FIGS. 4 to 7).
The first, second, and third bits 8, 9, and 10 provided above and below the square steel pipe 1 are both formed in a symmetrical shape and disposed at symmetrical positions. Only the bits 8, 9, 10 will be described.

The first bit 8 has a rectangular cross section (see FIG. 8), and in a side view (FIG. 3), the front end side is parallel to the front end edge of the side plate 5 of the blade edge 1B, and the rear end side is inclined slightly upward. The surface 8a is formed in a quadrilateral shape, and the tip side protrudes forward from the tip of the blade edge 1B, and the surface facing the inside of the blade edge 1B in a plan view (FIG. 2) is an inclined surface 8b that tapers. It is a wedge-shaped bit formed in a wedge shape. The upper side 8c of the first bit 8 is set at a position slightly lower than the upper surface 2a of the outer plate 2 of the blade 1B.
The second bit 9 has a rectangular cross section (see FIG. 5) that is slightly smaller than the cross section of the first bit 8 and is rectangular in plan view. The rear end of the second bit 9 is the side plate 5 of the blade 1B in side view. Is formed in a quadrangular shape having a tapered wedge shape with an inclined surface 9a facing downward, and the upper side portion 9b projects upward from the upper surface 2a of the outer plate 2 of the blade edge 1B. Yes.
In addition, the protrusion amount L1 from the side plate 5 of the first bit 8 and the second bit 9 to the outside (the side opposite to the inside of the blade edge 1B) in plan view is from the side plate 5 of the groove portion 7b in the protruding joint 7. The amount of outward protrusion is the same.

The third bit 10 has a rectangular cross section (see FIG. 6) and is formed in a plate shape parallel to the upper surface 2a of the outer plate 2 in a side view, and a rear end side of the outer plate 2 in a plan view. It is formed in a quadrilateral shape that is tapered like a tapered wedge by an inclined surface 10a that is parallel to the tip edge and faces the outside (the side opposite to the inside of the blade edge 1B), and further, the outer edge portion 10b is formed in the blade edge 1B. It protrudes outward from the side plate 5.
The protruding amount L2 of the second bit 9 upward from the upper surface 2a of the outer plate 2 and the plate thickness (height from the upper surface 2a of the outer plate 2) t1 of the third bit 10 are substantially equal to each other. The thickness is set to be slightly larger than the thickness t2 of the support piece 7a of the joint 7. The amount L3 of the third bit 10 protruding outward from the side plate 5 of the blade 1B is set slightly smaller than the amount of protrusion L1 of the first and second bits 8 and 9 from the outer plate 5. Yes. Further, the end portion (leading end portion) on the front end side of the square steel pipe body 1A of the protruding joint 7 is formed into a tapered wedge-shaped bit by providing an inclined surface 7d facing downward.

Next, a method for propelling a square steel pipe for tunnel lining according to an embodiment of the present invention will be described.
In constructing a tunnel lining body for constructing a three-dimensionally intersecting tunnel under a railway or road, when propelling the square steel pipe 1 having the above configuration into a natural ground, first, as shown in FIG. In the same manner as described above, the start shaft 11 and the arrival shaft 12 are excavated and formed in advance on both sides of the railroad or road R, and the excavation device 13 is installed in the start shaft 11 as necessary. After that, the square steel pipe 1 was installed horizontally on the front side of the excavation device 13 and was installed inside the square steel pipe 1 while operating the excavation device 13 to apply a thrust to the square steel pipe 1. Then, the screw conveyor device 15 having the rotary cutter 14 at the tip is operated.
Thereby, the natural ground 16 is excavated by the rotary cutter 14, and the natural ground 16 is broken by the cutting edge 1 </ b> B of the square steel pipe 1, so that the earth and sand generated by excavation of the natural ground 16 is the screw conveyor device. 15 is discharged outside the natural ground, and the square steel pipe 1 is propelled through the natural ground toward the reaching shaft 12 side. When the leading end of the square steel pipe main body 1A of the square steel pipe 1 reaches the side wall of the reaching shaft 12 and is buried in the natural ground, the blade 1B is removed from the square steel pipe main body 1A, It is used repeatedly after being attached to the leading end of the next square steel pipe 1 to be buried.

When propelling the square steel pipe 1 into the natural ground as described above, the male joint 6 of the subsequent square steel pipe 1 to be propelled is the same as that of the preceding square steel pipe 1 already embedded in the natural ground 16. The female joint 7 is fitted into the groove 7c of the groove part 7b (see FIG. 1), and the subsequent square steel pipe 1 is propelled in parallel along the preceding square steel pipe 1 using the groove 7c as a guide.
On the other hand, when the following square steel pipe 1 is propelled, as shown in FIG. 10 to FIG. 12, the tip edge of the blade edge 1B is the excavation area (face) 16a of the natural ground 16 by the rotating cutter 14 and the blade edge 1B. First, in the region 16c of the natural mountain 16 that is out of the cut region 16b of the natural mountain 16 by the leading edge of the first edge, the first bit 8 is located in the vicinity of the protruding joint 7 in the sectional view of the square steel pipe 1 (lower in FIG. 12). The excavated earth and sand 16x is taken in the direction of the arrow by the action of the inclined surface 8b and taken into the blade edge 1B, so that a cavity 17 is formed behind the first bit 8. Is done.

  Subsequently, the second bit 9 was not excavated by the first bit 8 in one predetermined region of the projecting joint 7 in the cross-sectional view of the square steel pipe 1 (a region corresponding to a part of the groove portion 7b). A natural ground portion (a natural ground portion that does not overlap with the first bit 8) is excavated, and the excavated earth and sand 16y is directed in the direction of the arrow by the action of the inclined surface 9a, and among the cavities 17 formed by the first bit 8 Since it is moved to the cavity 17a below the second bit 9, a cavity 18 having a cross-sectional shape is formed behind the second bit 9. The upper portion of the cavity 18 is a space in which the support piece 7b of the protruding joint 7 can be fitted.

Subsequently, the third bit 10 is the first and second bits in another predetermined region (region slightly larger than the portion corresponding to the support piece portion 7a) of the protruding joint 7 in the cross-sectional view of the square steel pipe 1. 8 and 9 excavate a natural ground portion that has not been excavated (a natural ground portion that does not overlap the first and second bits 8 and 9), and the excavated earth and sand 16z of the inclined surface 10a (see FIG. 2 and FIG. 8). Since it is moved and dropped onto the excavated earth and sand 16y behind the second bit 9 in the direction of arrow C by the action, the supporting piece 7a of the protruding joint 7 having the cross-sectional shape behind the second bit 9 is provided. A cavity 19 into which can be inserted is formed.
The protruding joint 7 moves in the propulsion direction of the square steel pipe 1 following the third bit 10, but the sectional shape of the protruding joint 7 has already been reached by the preceding first, second and third bits 8, 9, 10. Since the ground part corresponding to the most part (major part) is excavated, the projecting joint 7 itself is the natural part which the first, second and third bits 8, 9, 10 did not excavate. Is excavated with a wedge-shaped bit formed at the tip of the slab, and the excavated earth and sand are moved forward and dropped into the space 18a above the cavity 18.

As described above, according to the method for propelling a square steel pipe for tunnel lining according to the embodiment, the first, second, and third bits are arranged on the outer periphery of the corner of the blade edge 1B of the square steel pipe 1. 8, 9, and 10 are attached to the propulsion direction of the square steel pipe 1 so as to be slightly shifted in the direction orthogonal to the propulsion direction, and when propelling the square steel pipe 1 to the ground 16, The earth and sand 16x excavated by the first bit 8 is taken inside the blade 1B, and the earth and sand 16y excavated by the second bit 9 following the first bit 8 is moved into the cavity 17 formed by the first bit 8. The square steel pipe 1 is propelled while sequentially moving the earth and sand 16z excavated by the succeeding third bit 10 into the cavities 18 and 18a formed by the preceding first and second bits 8 and 9, and the third bit (Final bit) Square steel pipe after excavation by 10 Since a cavity including at least a majority of the cross section of the protruding joint 7 in the cross sectional view is formed, the first, second and third bits 8, 9, and 10 are newly excavated individually. The amount of the portion can be reduced, and even if the protruding joint 7 protrudes outward from the corner of the square steel pipe 1, the protruding joint 7 penetrates into the natural ground 16 and excavates. The amount of can be reduced.
Therefore, the first, second and third bits 8, 9, 10 and the projecting joint 7 can reliably prevent the deformation of the ground surface by compacting the surrounding natural ground portion 16c. The square steel pipe 1 can be propelled smoothly and quickly while reducing the thrust necessary for propelling the steel pipe 1 as much as possible and suppressing the deformation.

Moreover, according to the square steel pipe for tunnel lining according to the embodiment, the square steel pipe 1 is the side plate 5 at the corner of the outer periphery of the tip of the blade edge 1B, and in the cross-sectional view of the square steel pipe 1 A first bit 8 provided at a position near the protruding joint 7 at the corner, excavating the natural ground 16 and taking the earth and sand 16x into the blade 1B, and having a slightly larger cross-sectional area than the section of the protruding joint 7; Behind the first bit 8 and outside the side plate 5 at the corner of the outer periphery of the cutting edge 1B, the first bit 8 is partially overlapped with one predetermined region of the projecting joint 7 in the sectional view of the square steel pipe 1. A second bit 9 having a cross-sectional area smaller than that of the first bit 8 provided at a slightly shifted position from the bit 8, and an upper surface 2a of the outer plate 2 at the corner of the outer periphery of the blade edge 1B behind the second bit 9 In addition, another predetermined area of the protruding joint 7 in the sectional view of the square steel pipe 1 The second bit 9 and the third bit 10 provided with a position shifted so as to partially overlap with each other, and the protruding joint 7 is configured to be arranged behind the third bit 10, When the square steel pipe 1 is propelled, the space for fitting the majority of the projecting joint 7 attached to the outer peripheral corner of the square steel pipe 1 can be reliably formed. Can be reliably realized, and the structure is simple and can be easily implemented.
And since the said 1st bit 8 is a wedge-shaped bit, a structure is simple, and the ground 16 is easily collided with a wedge-shaped blade surface by the promotion of the square steel pipe 1, and the excavated earth and sand 16x is put into the blade edge 1B. Can be taken in reliably. Further, since the protruding joint 7 has a wedge-shaped tip, even if there is a natural ground portion that is not excavated by the preceding first, second, and third bits 8, 9, and 10, The part can be easily excavated with its own wedge-shaped bit and proceed without deformation.

In the method for propelling a square steel pipe for tunnel lining and the square steel pipe for tunnel lining according to the embodiment, the first, second, and third bits 8, 9, 10 are connected to the square steel pipe 1. Although it attached to the outer periphery of the corner | angular part in a cross sectional view, it is not restricted to this, According to the attachment position of the protrusion joint 7 in the cross sectional view of the square steel pipe 1, the outer plate 2, the inner plate 3, and the side plate of the square steel pipe 1 5 can be attached to the intermediate portion and other arbitrary positions by slightly shifting the position. In this case, the same effect as in the case of the above embodiment can be obtained. Further, when excavating a natural ground portion corresponding to the entire cross-sectional shape of the protruding joint 7 by the first, second, and third bits 8, 9, and 10, it is not necessary to form a wedge-shaped bit at the tip of the protruding joint 7. The configuration can be simplified.
Further, the number of bits provided on the outer periphery of the cutting edge 1B of the square steel pipe 1 is not limited to three, and two or four or more bits may be provided. When the number is increased and the mounting position is shifted little by little, one bit is provided. Since the amount of earth and sand to be excavated can be reduced, the thrust of the square steel pipe 1 can be further reduced.

  In addition, the first bit 8 is fixed as a wedge-shaped bit on the outer periphery of the tip of the cutting edge 1B of the square steel pipe 1, but instead of this, as shown in FIG. Rotating bits 21a and 21b which are arranged parallel or perpendicular to the side plate 5 and rotated by motors (driving means) 20a and 29b are attached, and openings are formed in the side plates (side walls) 5 behind the respective rotating bits 21a and 21b. 22 is provided, even when the square steel pipe 1 hits a hard soil ground, it can be easily excavated by the tips 21c and 21d provided on the outer peripheral portions or end face portions of the rotating bits 21a and 21b. The excavated earth and sand can be reliably taken into the inside of the blade edge 1B from the opening 22 of the side plate 5 of the blade edge 1B.

It is a front view of the square steel pipe for tunnel lining which concerns on one embodiment of this invention. It is a top view by the side of a blade edge in the square steel pipe for tunnel lining similarly. It is the side view by the side of the blade edge in the square steel pipe for tunnel lining similarly. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is DD sectional drawing of FIG. It is a perspective view by the side of a blade edge in the square steel pipe for tunnel lining concerning one embodiment of the present invention. It is sectional drawing which similarly shows the propulsion state of the square steel pipe for tunnel lining. It is sectional drawing (EE sectional drawing of FIG. 3) which similarly shows the excavation state of the natural ground by the edge of the square steel pipe for tunnel lining. It is sectional drawing (FF sectional drawing of FIG. 3) which similarly shows the excavation state of the natural ground by the edge of the square steel pipe for tunnel lining. It is sectional drawing (GG sectional drawing of FIG. 3) which similarly shows the excavation state of the natural ground by the edge of the square steel pipe for tunnel lining. It is sectional drawing which shows the other example of the 1st bit similarly provided in the front-end | tip of the edge of a square steel pipe for tunnel lining. It is a side view which shows the other example of the 1st bit similarly provided in the front-end | tip of the edge of a square steel pipe for tunnel lining.

Explanation of symbols

1 Square steel pipe for tunnel lining (square steel pipe)
1A Square steel pipe body 1B Cutting edge 2 Outer plate 3 Inner plate 4,5 Side plate 6 Male joint (projection joint)
7 Female joint (projection joint)
7a Support piece (stem part)
7b Groove part 7d, 8a, 8b, 9a, 10a Inclined surface 8, 9, 10 1st, 2nd, 3rd bit 13 Drilling device 16 Ground mountain 17, 17a, 18, 18a, 19 Cavity 20a, 20b Motor ( Driving means)
21a, 21b Rotating bit

Claims (5)

A plurality of rectangular steel pipes provided with protruding joints fixed along the longitudinal direction on the outer periphery are buried in the ground by sequentially propelling them into the ground along the cross section of the tunnel to be constructed. In the propulsion method of the square steel pipe that constitutes the tunnel lining body by connecting the steel pipes through the protruding joints,
A plurality of bits are attached to the outer periphery of the cutting edge of the square steel pipe while shifting the position in the direction orthogonal to the propulsion direction of the square steel pipe and the propulsion direction of the square steel pipe. The earth and sand excavated by the tip bit at the foremost end are taken into the inside of the blade edge, and the earth and sand excavated by the next bit following the tip bit are moved into the cavity formed by the tip bit, and the subsequent bits are sequentially The square steel pipe is propelled while moving the excavated earth and sand into the cavity formed by the preceding bit, and after the excavation by the final bit, a cavity including at least a majority of the cross section of the protruding joint in a cross-sectional view of the square steel pipe A method for propelling a square steel pipe for tunnel lining characterized by forming. Protruding joints fixed along the longitudinal direction on the outer peripheral part, being pushed and buried in a natural ground to be constructed, and adjacent ones facing the outer peripheral part are connected via the protruding joint A square steel pipe constituting a tunnel lining body by
The square steel pipe is the outer periphery of the tip of the blade, provided in the vicinity of the protruding joint in a cross-sectional view of the square steel pipe, and excavates natural soil to take earth and sand into the blade. The first bit having a cross-sectional area larger than the cross-section, and the outer periphery of the blade edge behind the first bit so that a part overlaps one predetermined region of the protruding joint in a cross-sectional view of the square steel pipe A second bit having a cross-sectional area smaller than that of the first bit provided at a position different from that of the first bit, and other protruding joints in the cross-sectional view of the square steel pipe on the outer periphery of the blade edge behind the second bit. A tunnel lining comprising: a second bit and a third bit shifted in position so as to partially overlap a predetermined area; and the protruding joint is disposed behind the third bit Square steel pipe.   The first bit is a wedge-shaped bit that is formed in a tapered wedge shape with the surface facing the inner side of the blade edge being an inclined surface, the tip portion protruding forward from the tip of the blade edge and fixed to the blade edge. The square steel pipe for tunnel lining according to claim 2, wherein:   The first bit is composed of a rotating bit that is rotated by a driving means, and an opening for taking excavated earth and sand by the rotating bit into the blade is provided on the side wall of the blade at the rear side of the rotating bit. The square steel pipe for tunnel lining according to claim 2. The square steel pipe for tunnel lining according to any one of claims 2 to 4, wherein a tip of the protruding joint is formed into a wedge-shaped bit capable of excavating a natural ground.

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