JP2005146711A - Shield machine for constructing branched tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and accurately perform work for excavating a tunnel by an excavator toward an existing tunnel and constructing a branched tunnel by communicating the tunnel with the existing tunnel in a crossing manner. <P>SOLUTION: When constructing the branched tunnel by communicating the tunnel T' excavated by the shield machine A with a predetermined part of the existing tunnel T, a front end face of a skin plate 1 of the shield machine A is formed into a curved end face 2 curved like side face recessed circular arc with the same degree of curvature as an outer peripheral wall face part joined with the existing tunnel T. After the shield machine A reaches the existing tunnel T, diameter of a cutter head 9 is contracted to make the skin plate 1 advance so that its curved end face 2 is abutted on the outer peripheral wall face part of the existing tunnel T and a wall body part surrounded by the skin plate 1 is dismantled to communicate the tunnel T' in a condition in which it is branched from the existing tunnel T. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a shield excavator for constructing a branch tunnel that communicates with an existing tunnel that is built in the ground from the outside.

  In order to build a tunnel that branches off from an existing tunnel built underground, a tunnel is dug from the start shaft side to the existing tunnel by a shield excavator and every time a fixed length of tunnel is excavated. After the shield excavator, a pipe is formed by sequentially adding buried pipes of a certain length, or a pipe is formed by lining the excavation wall according to excavation while assembling the segments in the machine. Then, after the shield excavator is stopped when the existing tunnel is reached, the branch tunnel is constructed by connecting the pipes constructed by the shield excavator so as to intersect the existing tunnel.

  At this time, the ground between the existing tunnel and the shield excavator is consolidated using an auxiliary method such as a chemical injection method or a freezing method, and the cutter head of the shield excavator is dismantled and removed from the shield excavator. While excavating the consolidated ground by human power and lining the excavated wall surface with sprayed concrete or the like, excavating the tunnel part to the outer peripheral wall surface of the existing tunnel and dismantling the outer peripheral wall surface of the existing tunnel A branch tunnel is built that crosses the tunnel.

  However, in such a construction method of a branch tunnel, the auxiliary construction method for solidifying the ground between the existing tunnel and the shield excavator requires a lot of time and labor, and the amount of ground excavation by manpower increases and the work efficiency increases. There was a problem that the remarkably decreased.

  For this reason, a shield excavator for branch tunnel excavation described in Patent Document 1 has been developed. As shown in FIGS. 17 and 18, this shield excavator is provided with a cutter head 42 for excavating the front ground at the open end of a skin plate 41 composed of front and rear body portions 41a and 41b which are connected to each other in a refractive manner. In the excavator body A1, a plurality of rectangular hood plate pieces 43a curved in an arc shape on the outer peripheral surface of the front body portion 41a of the skin plate 41 are combined in a cylindrical shape in the circumferential direction and adjacent hood plate pieces 43a, There is provided a hood body 43 formed by linking the opposite side end faces of 43a so as to be individually movable forward.

  And this tunnel excavator digs the tunnel T 'while constructing the segment lining on the excavation wall surface toward the existing tunnel T, and when the cutter head 42 reaches the existing tunnel T, the shield excavator is stopped, The hood plate pieces 43a are propelled while being press-fitted into the ground by a propulsion jack (not shown) mounted on the excavator body, and the tips of the respective hood plate pieces 43a abut against the outer peripheral wall surface of the existing tunnel T. By cutting, the ground taken in the hood body 43 and the outer ground are cut off, and then the ground in the hood body 43 is excavated and removed, and the inside of the excavator is disassembled and removed, and further, the hood body A branch port communicating with the tunnel T ′ is formed by breaking the outer peripheral wall surface portion of the existing tunnel T with which the tip of 43 abuts.

JP-A-8-86187

  However, according to the shield excavator for branch tunnel excavation described above, the plurality of hood plate pieces 33a constituting the cylindrical hood body 33 are made of a single rectangular plate material and thus have low rigidity. Therefore, when press-fitting into the ground from the front end of the skin plate 41, there is a concern about the collapse of the magnetic field in the soft ground due to bending deformation in the diameter increasing direction or the diameter reducing direction due to the resistance force from the ground side. On the other hand, in the construction on the hard ground, it is difficult to propel the hood plate piece 43a, and the construction work of the branch tunnel with respect to the existing tunnel T cannot be performed efficiently.

  Furthermore, since the front end surface of each hood plate piece 43a is formed as a linear end surface perpendicular to the length direction of the hood plate piece 43a, the outer peripheral wall surface of the existing tunnel curved in a circular arc shape. When a part of the front end surface is in contact with the point contact state, a gap is created between the other front end surface and the outer peripheral surface of the existing tunnel. Injection or a freezing operation must be performed over a wide range, which requires significant labor and labor.

  Also, after fixing the tip of each hood plate piece 43a to the outer peripheral wall of the existing tunnel, disassemble the shield excavator to a size that can be carried out by gas fusing, etc., and remove and collect it through the tunnel. However, not only does the disassembly work take a lot of time and labor, but there is a problem that the parts that can be reused after disassembly are limited.

  The present invention has been made in view of the problems as described above, and the purpose of the present invention is to connect a branch tunnel to an existing tunnel and communicate with each other efficiently and accurately. An object of the present invention is to provide a shield tunnel excavator for building a branch tunnel that can smoothly collect and remove a cutter head and the like.

  In order to achieve the above object, the shield tunnel excavator for branch tunnel construction according to the present invention excavates the tunnel toward the existing tunnel while excavating the front ground of the skin plate with the cutter head, and when this tunnel is reached. By removing the earth and sand taken in the skin plate with the tip surface of the skin plate in contact with the outer peripheral wall surface of the existing tunnel and destroying the peripheral wall portion of the existing tunnel surrounded by the tip surface of the skin plate In the shield tunnel excavator for constructing a branch tunnel that is configured to construct a branch tunnel that communicates with the existing tunnel in an intersecting manner, the front end face of the skin plate that is brought into contact with the outer peripheral wall surface of the existing tunnel as described in claim 1 Is formed on the curved end surface curved in a concave arc shape on the side surface that can be joined to the outer peripheral wall surface of the existing tunnel. The features.

  In the shield tunnel excavator for building a branch tunnel constructed in this way, the invention according to claim 2 covers the excavation wall surface of the branch tunnel with a small interval inward from the inner peripheral surface to the inner peripheral surface of the skin plate. An outer cylinder smaller in diameter than the pipe line made of the segment being worked on is integrally provided, and the inner cylinder is inserted into the outer cylinder so as to be movable in the front-rear direction, and is detachably connected to the outer cylinder. In addition, the front ground of the skin plate is excavated in a partition wall provided integrally with the front portion of the inner cylinder, and the outer diameter is reduced to be smaller than the inner diameter of the outer cylinder. It is characterized in that the cutter head that can be configured is rotatably supported.

  In the shield excavator according to claim 1 or 2, the invention according to claim 3 comprises a segment lining in which a pipe line is constructed on a digging wall surface, and is provided on the front end face of the segment lining. An excavator that is used in a so-called shield method for digging a tunnel while supporting a propulsion reaction force, and includes a front cylinder part that includes a front and rear body parts in which skin plates are refractably connected to each other, and inner and outer cylinders are also refractable to each other. In addition, a plurality of half-folded jacks and shield jacks are arranged in an annular hollow chamber formed between the inner peripheral surface of the skin plate and the outer peripheral surface of the outer cylindrical body. It is characterized by.

  On the other hand, in the shield excavator according to claims 1 and 2, the invention according to claim 4 is an excavator used in a propulsion method in which a pipeline is formed by a propulsion buried pipe, The rear end portion is connected to the front end of the propulsion buried pipe in a refractive manner, and the skin plate against the propulsion buried pipe is formed in an annular hollow chamber formed between the inner peripheral surface of the skin plate and the outer peripheral surface of the outer cylindrical body. And a plurality of middle-folding jacks that integrally refract the outer cylindrical body in a predetermined direction.

  According to the shield excavator for building a branch tunnel of the present invention, the front end surface of the skin plate that is brought into contact with the outer peripheral wall surface of the existing tunnel is formed into a curved end surface that is curved in a side concave arc shape that can be joined to the outer peripheral wall surface of the existing tunnel. Therefore, the curved front end surface of the skin plate of the shield excavator can be brought into full contact with the outer peripheral wall surface to be joined in the existing tunnel almost completely without any gaps. Auxiliary methods such as chemical injection and freezing treatment for the ground from between the outer peripheral surfaces of the tunnel can be reduced, and a highly accurate branch tunnel can be constructed.

  Furthermore, since the front end surface of the curve can be brought into full contact with and joined to the outer peripheral wall surface of the existing tunnel by propelling the entire skin plate, the skin plate can be efficiently joined to the outer peripheral wall surface of the existing tunnel. In addition, since the skin plate is formed in a single cylindrical shape that is not divided into a plurality of parts in the circumferential direction, the ground plate can be reliably supported without being bent and deformed with high rigidity.

  Further, according to the invention according to claim 2, since the outer cylinder is integrally provided on the inner peripheral surface of the skin plate, a double cylinder structure is formed by the skin plate and the outer cylinder. The strength is increased, and the skin plate can be accurately propelled while the ground is reliably supported by the skin plate along the tunnel excavation wall surface excavated by the cutter head.

  In addition, the outer diameter of the outer cylinder is smaller than the pipe line covering the excavation wall surface of the branch tunnel, and the inner cylinder is inserted into the outer cylinder so as to be movable in the front-rear direction. It is detachably connected to the cylindrical body, and further, the front ground of the skin plate is excavated in the partition wall provided integrally with the front portion of the inner cylindrical body, and the outer diameter is smaller than the inner diameter of the outer cylindrical body. Since the cutter head that can be reduced in diameter is rotatably supported, the excavation reaction force of the cutter head is supported on the skin plate and outer cylinder side when tunneling, but the skin plate and outer cylinder While it is possible to dig reliably by propelling the body integrally, when the tunnel is communicated with the existing tunnel after the tunnel excavation is completed, the cutter head is reduced in diameter and the inner cylinder is connected to the outer cylinder. By solving Easily recovered backwards together with the inner cylindrical body of the cutter head and guide the outer cylindrical body, it can be removed, re-use is possible.

  According to the invention of claim 3, the skin plate is composed of the front and rear body parts that are refractably connected to each other, and the inner and outer cylinders are also divided into a front cylinder part and a rear cylinder part that are also refractable to each other, In addition, since a plurality of middle-folded jacks and shield jacks are arranged in an annular hollow chamber formed between the inner peripheral surface of the skin plate and the outer peripheral surface of the outer cylindrical body, the inner cylindrical body exists. Despite the fact that it has a structure in which the folding jack or shield jack is arranged directly on the inner circumferential surface of the skin plate, not on the inner circumferential surface of the inner cylinder, the operating force of the folding jack is directly applied. It can transmit between the front and rear body parts of the skin plate, and the front and rear body parts of the skin plate and the front and rear cylinder parts of the inner and outer cylinders can be integrated at the same time with a relatively small expansion and contraction force without using a large, middle-folded jack. Refracted by each other The angle of the outer cylinder required to correct the direction of the shield excavator and the curved tunnel excavation can be reliably obtained, and the front end face of the segment where the axis of the shield jack rod is installed on the excavation wall The rod can be arranged as close as possible or abutted as much as possible, can be operated stably with almost no bending force acting on the rod, and a large working space in the machine can be secured. It is possible to improve work efficiency.

  Similarly, in the shield excavator according to claim 4 for the propulsion method, the rear end portion of the skin plate is connected to the front end of the propulsion buried pipe in a refractive manner, and the inner peripheral surface of the skin plate and the outer cylinder Since a plurality of middle-folding jacks that refract the skin plate and the outer cylindrical body in a predetermined direction with respect to the propulsion embedded pipe are mounted in an annular hollow chamber formed between the outer peripheral surfaces of the body, The digging direction of the shield excavator can be easily and accurately directed to the propulsion buried pipe by the folding jack. In any of the above shield excavators, the folding jack or the shield jack is disposed in an annular hollow chamber formed between the inner peripheral surface of the skin plate and the outer peripheral surface of the outer cylindrical body. These devices can be placed in a predetermined position without being obstructed by the various devices and without interfering with the devices.

  Next, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a shield excavator A for excavating a tunnel T ′ that becomes a branch tunnel toward an existing tunnel T by a shield method. When the front end surface of the cylindrical skin plate 1 having a certain length is viewed from the side, it is brought into contact with the outer peripheral wall t curved in a convex arc shape of the existing tunnel T to be joined, and a concave arc shape that can be joined. A curved end surface 2 is formed. That is, the center portion of the skin plate 1 in the vertical direction (height direction) is recessed most backward in the front end surface of the skin plate 1, and gradually gradually toward the front gradually from the center portion to the vertical periphery. It is formed on a curved concave arc-shaped curved end surface 2.

  When the tunnel T ′ is excavated so that the axis of the shield excavator A intersects the tunnel axis of the existing tunnel T, the concave arcuate curved end surface of the skin plate 1 joined to the outer peripheral wall surface of the existing tunnel T is provided. 2 is located at the center of the skin plate 1 in the height direction, but the axis of the shield excavator A is displaced vertically with respect to the tunnel axis of the existing tunnel T. In the case of abutting and joining the existing tunnel T on the wall surface on the upper peripheral side or the wall surface on the lower peripheral side in a crossing manner, it is natural that the concave arc-shaped curve of the skin plate 1 is formed. When the most depressed portion of the end surface 2 is deviated in the vertical direction, and the tunnel T ′ intersects the existing tunnel T without being orthogonal, the skin plate 1 In the concave arcuate curved end face 2, the depression is deep on one side and shallow on the other side.

  This skin plate 1 is divided into a front trunk portion 1a and a rear trunk portion 1b, like an ordinary shield excavator, and an outer peripheral surface projecting from the front end of the rear trunk portion 1b is arcuate in the front-rear direction. The inner peripheral surface of the rear end of the front barrel portion 1a is refractably connected to the rear barrel portion 1b via a sealing material on the bent middle portion 1c.

  Further, the skin plate 1 is composed of a segment S that covers the excavation wall surface of the tunnel T ′ that is excavated by the shield excavator A with a small gap from the inner peripheral surface of the skin plate 1. An outer cylinder 3 smaller in diameter than the inner diameter of the pipe P is disposed concentrically with the skin plate 1 and the outer cylinder 3 is integrated at a predetermined interval in the length direction by a plurality of annular connecting plates 10. The hollow chamber 5 having an annular cross section is formed between the inner peripheral surface of the skin plate 1 and the outer peripheral surface of the outer cylindrical body 3.

  The front end of the outer cylindrical body 3 is located at a position behind the front end of the skin plate 1 with a small interval, and the front end of the outer cylindrical body 3 is integrally fixed to the inner peripheral surface of the front end portion of the skin plate 1. The front end portion of the skin plate 1 protrudes forward from the annular connecting plate 10 to form the front end portion in the hood portion 1a1, and the outer cylindrical body 3 is connected to the inner bent portion 1c of the skin plate 1. Is divided into a long front cylinder part 3a and a short rear cylinder part 3b which can be refracted from each other, and the rear cylinder part 3b is located behind the skin plate 1. It is provided inside the portion extending from the front end of the body portion 1a to the front end of the middle bent portion 1c.

  The inner cylinder 4 is inserted into the outer cylinder 3 so as to be movable in the front-rear direction. Specifically, guide rollers 11 are rotatably supported at a plurality of locations in the front-rear direction and the circumferential direction of the outer cylindrical body 3, and the outer peripheral surface of the inner cylindrical body 4 is supported by these guide rollers 11. The inner cylindrical body 4 is configured to be able to be drawn backward from the state inserted in the outer cylindrical body 3 and the inner cylindrical body 4 is also refractable to each other like the outer cylindrical body 3. The divided portion is provided so as to overlap the inside of the divided portion between the inner and outer outer cylindrical body portions 3a and 3b of the outer cylindrical body 3, and is integrated with the skin plate 1 and the outer cylindrical body 3. Therefore, it can be refracted from the divided portion.

  Further, the sealing material 12 is provided around the front and rear end portions and the intermediate portion of the inner peripheral surface of the front cylindrical portion 3a of the outer cylindrical body 3, and the front cylindrical portion 4a of the inner cylindrical body 4 is provided around these sealing materials 12. The front and rear end portions and the intermediate portion are brought into close contact with each other to provide water-stopping properties. Further, when the inner cylinder 4 is inserted into the outer cylinder 3 so as to have an inner / outer double cylinder structure, when the tunnel excavation by the shield excavator A is performed, the front cylinder portion 4a of the inner cylinder 4 is removed. The front cylinder part 3a of the cylinder 3 is detachably connected by an appropriate connector 13, for example, a bolt, and these inner and outer cylinders 3, 4 are fixed integrally.

  In the hollow chamber 5 having an annular cross section between the skin plate 1 and the outer cylinder 3, a plurality of half-folded jacks 6 and shield jacks 7 are arranged at predetermined intervals in the circumferential direction. As shown in FIG. 2, the middle folding jacks 6 are arranged such that two sets with a small interval in the circumferential direction are arranged as a set, and four sets are arranged on the top, bottom, left and right inside the hollow chamber 5. The front end of the jack 6 is pivotally attached to a bracket 14a projecting on the inner peripheral surface of the longitudinal direction of the front body portion 1a of the skin plate 1, while the rear end is connected to the front end of the rear body portion 1b of the skin plate 1. The intermediate bent portion 1c is connected to the bracket 14b projecting on the inner peripheral surface thereof by pivotally pivoting on the inner peripheral surface.

  Each shield jack 7 is detachably fixed by an appropriate fixing tool (not shown) while being placed on the inner peripheral surface of the bent portion 6, and the rear end portion is the rearmost portion. The spreader 7b is inserted into and supported by the annular connecting plate 10 on the side, protrudes rearward, and is pressed against the front end surface of the segment S constituting the pipe P. On the other hand, a plurality of expansion jacks 15 (the same number as the folding jacks 6) are arranged along the inner peripheral surface of the inner cylinder 4 so as to overlap the inner folding jacks 6. The front and rear ends of 15 are pivotally attached to the inner peripheral surfaces of the front and rear cylinder parts 4a and 4b of the inner cylinder 4, and the front and rear cylinder parts 4a and 4b are connected to each other so as to be refractable.

  Further, an erector device 16 for assembling the segment S at the rear end of the rear cylindrical body portion 4b of the inner cylindrical body 4 is provided to project rearward from the rear cylindrical body portion 3b of the outer cylindrical body 3. ing. In this erector device 16, a circular rail member 16a having an outer diameter smaller than the inner diameter of the pipe P is fixed to the rear end portion of the rear cylindrical portion 4b of the inner cylindrical body 4, and a motor ( A ring body 16b that is rotated by driving is rotatably supported, and an erector 16c is mounted on the ring body 16b.

  A partition wall 8 is provided in the front portion of the inner cylinder 4 by integrally fixing its outer peripheral end surface to the inner periphery of the inner cylinder body 4. A cutter head 9 for excavating the front ground is rotatably supported. As shown in FIGS. 1 and 3, the cutter head 9 supports the rotation center shaft 17 at the center of the partition wall 8, and extends from the tip of the rotation center shaft 17 toward the outer diameter direction. A plurality of (four in the figure) spokes 9a that are slightly shorter than the inner diameter of the outer cylindrical body 3 and have a plurality of cutter bits 9c projecting forward on both sides of the front face are provided radially. And adjacent spokes 9a, 9a are connected to each other between the outer end-facing side surfaces by an arc-shaped connecting piece 9d, and each spoke 9a is formed into a cylindrical hollow spoke 9a whose outer end face is open. The outer spoke piece 9b is accommodated in the inner part of the outer plate and the jack 18 attached to the spoke 9a is actuated to cause the outer spoke piece 9b to protrude from the open end of the hollow spoke 9a so that the spoke length can be increased. In the inner peripheral surface of the inner cylinder 4 from the length reaching It can be expanded and contracted to a length that fits in A plurality of cutter bits 9c are projected on both sides of the front surface of the outer spoke piece 9b, and a center bit 9c 'is projected on the front surface of the rotation center shaft 17.

  In addition, arm members 19 are protruded rearward at several locations on the outer periphery of the back surface of the cutter head 9, and the rear ends of these arm members 19 are integrally connected by an annular frame member 20. The frame member 20 is rotatably supported on the inner peripheral surface of the front cylindrical portion 4a of the inner cylindrical member 4 projecting forward from the partition wall 8. Further, an internal gear 21 is attached to the rear end surface of the annular frame member 20. On the other hand, a drive motor 22 is mounted on the rear surface of the outer peripheral portion of the partition wall 8 and the small gear 23 fixed to the rotation shaft of the drive motor 22 is engaged with the internal gear 21. The cutter head 9 is configured to rotate.

  Further, a space between the rear surface of the cutter head 9 and the front surface of the partition wall 8 is formed in a sand chamber 24 that takes in the sand excavated by the cutter head 9 and temporarily retains it. The excavated sediment is discharged backward through the soil means 25. As shown in FIG. 1, the earth discharging means 25 is a screw conveyor, and its front end opening penetrates the lower part of the partition wall 8 so as to face the lower end of the earth and sand chamber 24 and from the partition wall 8 toward the rear. It is arranged in a state inclined obliquely upward.

  The arm member 19 of the cutter head 9 is provided with a telescopic stirring rod 26 that protrudes in the outer diameter direction, and covers 27 are provided at several locations on the outer peripheral surface of the rear body 1b of the skin plate 1. A covered backfill injection tube (not shown) is provided. Further, in the hollow chamber 5 between the skin plate 1 and the outer cylindrical body 3, a chemical solution injection pipe 29 for ground improvement is disposed from the rear body portion 1b side of the skin plate 1, and the tip of the chemical solution injection pipe 29 is disposed. Passes through the front end of the skin plate 1 and is opened to the outer peripheral ground side.

  Next, in order to construct the branch tunnel T ′ for communicating with the existing tunnel T by the shield tunnel excavator A for branch tunnel construction configured as described above, first, the shield excavator A is set to a start shaft (not shown). ), The outer spoke piece 9b of the cutter head 9 is extended and the cutter head 9 is expanded in diameter, and the ground is excavated from the skin plate 1 while rotating, and the excavation wall surface t ' Then, the pipe P is formed by assembling the segment S by the erector device 26. The shield excavator is propelled by pressing the spreader 7b attached to the tip of the rod of the shield jack 7 against the front end surface of the segment S previously constructed on the excavation wall surface t 'and extending the rod 7a.

  At this time, the segment S is assembled by the erector device 16 in the rear trunk portion 1b of the skin plate 1, and sent to the excavation wall surface t 'along the inner peripheral surface of the rear trunk portion 1b as the shield excavator A advances. On the other hand, since all the shield jacks 7 are mounted on the inner peripheral surface of the skin plate 1, the axial center extension line of the rod 7a is as close or as close as possible to the front end surface of the segment S. The rod 7a 7 can be driven in a stable state by applying a reaction force to the front end surface of the segment S without causing an excessive force such as bending, and a wide working space in the machine can be secured. Work efficiently.

  The propulsive force of the shield jack 7 that takes a reaction force on the front end surface of the segment S is the front barrel portion 1a and the front barrel portion 1a through the bent middle jack 6 from the rear barrel portion 1b side of the skin plate 1 to which the shield jack 7 is fixed. This is transmitted to the front cylindrical portion 3a of the outer cylindrical body 3 integral with the front barrel portion 1a, and further detachably connected to the front cylindrical portion 3a of the outer cylindrical body 3 by a connecting tool 13 such as a bolt. The light is transmitted from the front cylindrical portion 4a of the inner cylindrical body 4 to the cutter head 9 via a partition wall 8 provided integrally with the inner cylindrical body 4. In other words, the pressure from the face acting on the surface of the cutter head 9 during excavation causes the skin plate 1 and the shield jack 7 to be moved from the front side cylinder parts 3a and 4a of the inner and outer cylinders 3 and 4 connected together. Via the front end face of the lining segment S. Note that the rear cylinder part 4b of the inner cylinder 4 is pulled forward via an expansion / contraction jack 15 connected to the front cylinder part 4a and moves forward integrally.

  Further, when the direction of the shield excavator is corrected or the curved tunnel portion is excavated while the tunnel is being excavated, the front trunk portion 1a of the skin plate 1 is moved to the rear trunk portion 1b by actuating the bent jack 6. Is refracted in a predetermined direction. At this time, the front cylindrical portion 3a of the outer cylindrical body 3 integral with the front barrel portion 1a of the skin plate 1 is also refracted integrally with the rear cylindrical portion 3b, and the front cylindrical body of the outer cylindrical body 3 is also refracted. The front cylindrical portion 4a of the inner cylindrical body 4 is pressed by the inner peripheral surface of the portion 3a, and the front barrel of the skin plate 1 with respect to the rear cylindrical portion 4b while expanding and contracting the expansion jack 15 according to the amount of refraction. The portion 1a and the front cylindrical portion 3a of the outer cylindrical body 3 are refracted by the same angle in the same direction. In this way, by tunneling the shield excavator A, the tunnel T ′ is excavated in a predetermined direction along the planned line toward the existing tunnel T. The excavated earth and sand are sent from the earth and sand chamber 24 to the earth discharging means 25 and discharged from the earth discharging means 25 to the start shaft side through the tunnel T ′.

  Thus, the tunnel excavator A is propelled while excavating the front ground of the skin plate 1 with the cutter head 9 to build the tunnel T ′, and the shield excavator A is located at a predetermined position in the existing tunnel T, that is, the existing tunnel. When reaching a portion where the tunnel T ′ communicates with T in a state where the tunnel T ′ is branched in an intersecting manner, the front end opening of the skin plate 1 is stopped in a state where the outer peripheral wall surface t of the portion is opposed. In this state, the tunnel T ′ constructed by the shield excavator A is connected to and communicated with the existing tunnel T to branch the tunnel T ′ from the existing tunnel T. Next, a branching operation process of the tunnel T ′ will be described with reference to FIGS. 1 and 4 to 6.

  First, FIG. 1 shows a state in which the shield excavator A reaches the existing tunnel T and the cutter head 9 protruding from the hood portion 1a1 of the skin plate 1 faces a predetermined portion on the outer peripheral wall surface t of the existing tunnel T. Therefore, the center bit 9c ′ of the cutter head 9 is made to coincide with the center of the branch opening B (shown in FIG. 6) provided to communicate the tunnel T ′ with the wall of the existing tunnel T. Thus, the opening portion B is brought close to or in contact with a predetermined portion of the outer peripheral wall surface t of the existing tunnel T, or a part of the wall portion of the existing tunnel T is perforated by the center bit 9c ′. ing.

  When the shield excavator A reaches a predetermined position in the existing tunnel T in this way, first, as shown in FIG. 4, the outer spoke pieces 9b of the cutter head 9 are contracted into the respective spokes 9a, whereby the cutter head 9 The outer diameter is made smaller than the inner diameter of the outer cylinder 3 and the stirring rod 26 attached to the arm member 19 of the cutter head 9 is contracted. Further, the connecting tool 13 made of a bolt integrally connecting the front side cylinder part 3a of the outer cylinder 3 and the front side cylinder part 4a of the inner cylinder 4 is removed, and the inner and outer cylinders 3 and 4 are moved forward and backward. The opposing end portions of the front and rear cylinder parts 4a and 4b of the inner cylinder 4 are integrally connected and fixed by a connecting metal fitting 28.

  After that, when the rod of the shield jack 7 is extended, and the skin plate 1 is advanced by applying a reaction force to the front end of the segment S forming the pipe P, the diameter of the hood portion 1a1 of the skin plate 1 is reduced. While passing through the outer periphery of the cutter head 9 and enclosing the cutter head 9, it is plunged into the ground between the cutter head 9 and the existing tunnel T and propelled, and a branch opening B in the outer peripheral wall surface t of the existing tunnel T The front end face is brought into contact with the position where the sword should be formed. At this time, the inner cylinder body 4 provided with the cutter head 9, the erector 16 and the like is fixed by a traction device such as a winch if necessary.

  When the skin plate 1 is thus propelled, the outer cylindrical body 3 integrated with the skin plate 1 causes the guide plate 11 provided on the inner peripheral surface thereof to roll on the outer peripheral surface of the inner cylindrical body 4 while the skin plate 1 1 and the skin plate 1 can be smoothly and reliably propelled. Further, when the front end surface of the skin plate 1 is brought into contact with the outer peripheral wall surface t of the existing tunnel T, the front end surface is previously aligned with the outer peripheral wall surface t of the wall portion where the branch opening B in the existing tunnel T is to be formed. Accordingly, the curved end surface 2 can be accurately brought into contact with a predetermined portion of the outer peripheral wall surface t of the existing tunnel T with almost no gap. In addition, in the figure, in order to clarify the shape relationship between the outer peripheral wall surface t of the existing tunnel T and the front end curved end surface 2 of the skin plate 1, a state in which a gap is provided entirely between these opposed surfaces is shown. Yes.

  In this way, after joining the curved end surface 2 of the skin plate 1 to the portion where the opening B for branching in the outer peripheral wall surface t of the existing tunnel T is to be formed, the outer peripheral wall surface t of the existing tunnel T and the skin are passed through the chemical injection pipe 29 from inside the machine. The water-stopping layer C is formed by injecting and solidifying the chemical into the ground around the joint with the curved end surface 2 of the plate 1. Thereafter, the earth and sand on the front side of the cutter head 9 taken into the front end portion of the skin plate 1 is appropriately removed.

  Next, after laying a rail (not shown) on the bottom of the pipeline P behind the shield excavator A, the screw conveyor as the soil removal means 25 is removed from the shield excavator A as shown in FIG. It is placed on a carriage (not shown) that travels on the rail, and the inside of the pipe P is collected and removed to the start shaft side. The rail may be a rail laid on the bottom of the pipe P for carrying in a member such as a segment from the start shaft when the tunnel is excavated by the shield excavator A.

  Further, a recovery guide roller 30 that rolls on the rail is attached to the lower peripheral portion of the inner cylinder 4, and the inner cylinder 4 including the cutter head 9 and the erector device 16 is pulled from the rear side by a traction device. Move to the start shaft side and collect. The inner cylinder 4 provided with the cutter head 9 and the erector device 16 collected in this way is used again for another shield work.

  On the other hand, the skin plate 1 covering the excavation wall t is left at the place where the shield excavator reaches, but the bent jack 6 and the shield jack 7 attached to the skin plate 1 are removed from the skin plate 1 and collected. And used for the next shield construction. Next, the wall portion of the existing tunnel T surrounded by the front end face of the skin plate 1 is disassembled and removed from the existing tunnel T or from the tunnel T ′ side, as shown in FIG. An opening B leading to the inside of the tunnel T ′ is opened, and the opening B and the front end surface of the skin plate 1 are integrated by welding or an appropriate lining process, so that the above tunnel is passed through the opening B from the existing tunnel T. Completed the construction of a diverging tunnel with T 'diverging. In addition, the folded jack 6 and the shield jack 7 disposed in the hollow chamber 5 between the skin plate 1 and the outer cylinder 3 are also collected.

  In the shield tunnel excavator for building a branch tunnel in the above embodiment, the cutter head 9 is configured to dig directly in a state where the cutter head 9 protrudes forward from the front end surface curved in a concave arc shape on the side surface of the skin plate 1. However, with this configuration, a crescent-shaped gap is formed between the back surface of the cutter head 9 and the curved end surface 2 of the skin plate 1 as viewed from the side surface. FIG. 7 shows a shield tunnel excavator for building a branch tunnel that is configured so that such a crescent-shaped gap does not occur even though the skin plate 1 having the curved end face 2 is provided.

  That is, in the shield excavator A ′, in the shield excavator A shown in the above embodiment, the front end hood portion 1a1 of the skin plate 1 is formed along the front inner peripheral surface of the front trunk portion 1a of the skin plate 1. A short cylindrical inner hood 1 'having a length slightly longer than the length and formed on a straight front end surface 2' having a vertical front end surface can be protruded from the front end of the skin plate 1 The structure is arranged.

  Specifically, as shown in FIG. 8, a skin plate 1 whose front end surface is formed on a curved end surface 2 having a side-side concave arc shape, and an outer cylindrical body 3 disposed inside the skin plate 1, The outer peripheral end face of the foremost annular connecting plate 10 ′ whose inner peripheral end is integrally connected to the front end of the outer cylindrical body 3 is formed in front of the skin plate 1. The inner hood 1 'is inserted and supported between the outer peripheral end face of the annular connecting plate 10' and the front inner peripheral face of the skin plate 1 so as to be slidable back and forth without being connected to the inner peripheral face of the part. A guide port 31 is provided, and a plurality of hood slide jacks 32 are mounted in the hollow chamber 5 along the inner peripheral surface of the front body portion of the skin plate 1 at predetermined intervals in the circumferential direction. The rod front end is connected to the rear end surface of the inner hood 1 ′. Since the other structure is the same as that of the shield tunnel excavator A for building a tunnel shown in FIG. 1, the same parts are denoted by the same reference numerals and detailed description thereof is omitted.

  Since it comprised in this way, when excavating tunnel T 'toward the existing tunnel T from the starting pit side, as shown in FIG. 1, the front end part of inner hood 1' is extended by extending the hood slide jack 32. The skin plate 1 protrudes forward from the front end of the hood portion 1a1 and the straight front end surface 2 'is brought into an excavation state by a normal shield method that reaches the vicinity of the back surface of the cutter head 9. In this state, the tunnel T ′ is dug until reaching the existing tunnel T, and the pipe wall P is formed by lining the excavation wall surface t ′ with the segment S.

  When the shield excavator A ′ reaches a predetermined position in the existing tunnel T, as shown in FIG. 9, the outer spoke pieces 9b of the cutter head 9 are contracted into the respective spokes 9a to reduce the diameter of the cutter head 9. The stirring rod 26 is also contracted, and the inner and outer cylinders are further removed by removing the connecting tool 13 consisting of a bolt that integrally connects the front cylinder part 3a of the outer cylinder 3 and the front cylinder part 4a of the inner cylinder 4 together. 3 and 4 are moved relative to each other in the front-rear direction, and then the rod of the shield jack 7 is extended so that the reaction force is applied to the front end of the segment S so that the skin plate 1 is integrated with the outer cylinder 3 and the inner hood 1 ′. The vertical center of the straight front end surface 2 ′ of the inner hood 1 ′ protruding from the hood portion 1a1 of the skin plate 1 is brought into contact with the opposing portion of the outer peripheral wall surface of the existing tunnel T. Further, the opposing ends of the front and rear cylinder parts 4a and 4b of the inner cylinder 4 are integrally connected and fixed by a connecting metal fitting 28 (shown in FIG. 10).

  From this state, the shield jack 7 is further extended to propel the skin plate 1 integrally with the outer cylinder 3, and at the same time, the hood slide jack 32 is contracted by the same length according to the extension amount of the shield jack 7. As a result, the straight front end surface 2 ′ of the inner hood 1 ′ is moved backward relative to the skin plate 1 while maintaining the state in which the straight front end surface 2 ′ is in contact with a part of the outer peripheral wall surface t of the existing tunnel T as described above. To immerse it in the guide port 30 (see FIG. 10).

  As described above, when the skin plate 1 is propelled, the cutter head 9 is housed in the outer cylindrical body 3 and the skin plate 1 enters and propels into the ground between the cutter head 9 and the existing tunnel T, thereby Similar to the embodiment, the curved end face 2 is brought into full contact with the position where the branch opening B is to be formed in the outer peripheral wall surface t of the existing tunnel T. Thereafter, as in the above embodiment, the chemical solution is injected into the ground around the joint portion between the outer peripheral wall surface t of the existing tunnel T and the curved end surface 2 of the skin plate 1 through the chemical solution injection pipe 29 and solidified. The water blocking layer C is formed.

  After that, the sand on the front side of the cutter head 9 taken into the front end of the skin plate 1 is appropriately removed and the screw conveyor as the earth discharging means 25 is removed from the shield excavator A and collected and removed to the start shaft side. The guide roller 30 attached to the lower peripheral portion of the inner cylinder 4 is placed on the rail in the tunnel T ′, and the inner cylinder 4 provided with the cutter head 9 and the elector device 16 is pulled from the rear side by a traction device. As a result, it is moved to the start shaft side and collected (see FIGS. 11 and 12).

  Next, the wall portion of the existing tunnel T surrounded by the front end surface of the skin plate 1 is disassembled and removed from the existing tunnel T or from the tunnel T ′ side, and the opening that leads from the existing tunnel T to the tunnel T ′ is opened. Opening the part B and integrating the opening B and the front end face of the skin plate 1 by welding or the like completes the construction of the branch tunnel that branches the tunnel T ′ from the existing tunnel T through the opening B. To do. The folded jack 6 and the shield jack 7 attached to the skin plate 1 are removed from the skin plate 1 and collected.

  In both the shield excavators A and A ′, the shield jack 7 is attached to the inside of the machine, and the erector device 16 is disposed. The front end surface of the segment S assembled on the tunnel excavation wall surface by the erector device 16 is provided. The excavator is used in a so-called shield method in which the shield excavator is excavated while receiving the propulsion reaction force of the shield jack 7. The excavator is pushed and propelled following the shield excavator excavating from the start shaft. As a result, the shield excavator is dug, and the buried pipe is sequentially press-fitted into the excavation wall surface in series to form a pipe line P ′ by these buried pipes. Next, still another embodiment of the present invention in the case where the excavator A '' is configured to construct the branch tunnel T ′ will be described.

  FIG. 13 shows a shield excavator A ″ for the propulsion method. The rear body 1b of the cylindrical skin plate 1 is shortened so that the rear end of the rear body 1b is connected to the pipe P ′. It is integrally connected and fixed to the front end surface of the foremost buried pipe to be formed, and is arranged in the front body portion 1a of the skin plate 1 at predetermined intervals in the front-rear direction as in the above embodiment. An outer cylindrical body 3 that is integrally connected and fixed via a plurality of annular connecting plates 10 is provided. Note that the outer diameter of the outer cylinder 3 is smaller than the inner diameter of the pipe line P ′.

  The front end surface of the skin plate 1 is a concave arc shape that can be fully abutted and joined to the outer peripheral wall surface t curved in the convex arc shape of the existing tunnel T to be joined, as seen from the side, as in the above embodiment. It is formed on the curved end surface 2 that is curved in a straight line. Furthermore, several middle-folded jacks are provided at predetermined intervals in the circumferential direction in the rear part of the hollow chamber 5 having an annular cross-section formed between the opposed surfaces of the front body part 1a of the skin plate 1 and the outer cylindrical body 3. 6 is attached and the front end thereof is pivotally attached to the inner peripheral surface of the front barrel portion 1a, while the rear end portion is the inner peripheral surface of the bent portion 1c in which the front and rear barrel portions 1a and 1b are bent flexibly. It is pivotally attached to.

  In addition, an inner cylinder 4 having substantially the same length as that of the outer cylinder 3 is mounted in the outer cylinder 3 on the front and rear end portions on the inner peripheral surface of the outer cylinder 3 and the intermediate portion in the length direction. In the state where the inner and outer cylinders 3 and 4 are combined so as to have an inner and outer double cylinder structure, the inner and outer cylinders 3 and 4 are mutually inserted. Are detachably connected by an appropriate connector 13, for example, a bolt.

  Further, in the same manner as in the above-described embodiment, a partition wall 8 is provided in the front portion of the inner cylindrical body 4 by fixing its outer peripheral end surface integrally to the inner peripheral surface of the inner cylindrical body 4. A cutter head 9 for excavating the front ground of the skin plate 1 is rotatably supported at the center of the plate. Since the rotation driving mechanism and the mechanism for expanding and reducing the outer diameter of the cutter head 9 are the same as those in the above embodiment, the same portions are denoted by the same reference numerals and detailed description thereof is omitted.

  Next, in order to build the branch tunnel T ′ for communicating with the existing tunnel T by the shield tunnel excavator A ″ constructed in this way, first, this shield excavator A ″ is set to the start shaft ( A propulsion jack that is installed in the vertical shaft of the skin plate 1 and that has a fixed length of buried pipe connected to the rear end of the rear body 1b of the skin plate 1. By extending the shield excavator A ″ by extending the outer spoke piece 9b of the cutter head 9 and rotating the cutter head 9 in a state where the diameter of the cutter head 9 is increased, the ground in front of the skin plate 1 is moved. Dig up. Then, when one buried pipe is buried, the next buried pipe is added and the rear end face is pushed forward by a propulsion jack, and the shield excavator A '' is dug to cover the excavated wall surface with the buried pipe P 'Will form.

  Thus, when the shield excavator A ″ reaches the predetermined position in the existing tunnel T as shown in FIG. 13 while forming the pipe P ′, the outer spoke piece 9b of the cutter head 9 is moved as shown in FIG. The cutter head 9 is contracted into each spoke 9a to reduce the diameter of the cutter head 9 to a smaller diameter than that of the outer cylinder 3, and a connecting tool 13 made of a bolt integrally connecting the outer cylinder 3 and the inner cylinder 4 is provided. After removing and allowing the inner and outer cylinders 3 and 4 to move relative to each other in the longitudinal direction, the skin jack 1 is moved forward integrally with the outer cylinder 3 by extending the propulsion jack installed in the start shaft. The curved end surface 2 of the front end of the skin plate 1 is brought into full contact with the position where the opening B for branching in the outer peripheral wall surface t of the existing tunnel T is to be formed. At this time, the inner cylinder body 4 provided with the cutter head 9 and the soil discharging means 25 is fixed to the partition wall 8 from behind by a traction device such as a winch.

  After that, as in the above embodiment, the chemical solution is injected into the ground around the joint portion between the outer peripheral wall surface t of the existing tunnel T and the curved end surface 2 of the skin plate 1 through the chemical solution injection pipe (not shown). Then, after the water-stopping layer C is formed by solidifying, the sand on the front side of the cutter head 9 taken into the front end portion of the skin plate 1 is appropriately removed and the screw conveyor as the soil discharging means 25 is connected to the shield excavator A It is removed from '' and recovered and removed to the start shaft side, and then the inner cylinder 4 provided with the cutter head 9 is pulled to the start shaft side by pulling with the traction device and recovered (FIGS. 15 and 16). reference). At this time, although not shown, the earth removing means 25 and the inner cylindrical body 4 are removed to the start shaft side and collected by using a rail laid on the bottom of the pipe P ′ as in the above embodiment. It is.

  Next, the wall portion of the existing tunnel T surrounded by the front end surface of the skin plate 1 is disassembled and removed from the existing tunnel T or from the tunnel T ′ side, and the opening that leads from the existing tunnel T to the tunnel T ′ is opened. Opening the part B and integrating the opening B and the front end face of the skin plate 1 by welding or the like completes the construction of the branch tunnel that branches the tunnel T ′ from the existing tunnel T through the opening B. To do. The folded jack 6 attached to the skin plate 1 is removed from the skin plate 1 and collected.

  In any of the above-described embodiments, the spoke 9a of the cutter head 9 is formed by hollowly forming the spoke 9a so that the outer spoke piece 9b can be retracted and mounted in the spoke 9a. The outer spoke piece 9b is projected and retracted from the open end of the hollow spoke 9a by the operation of the jack, and the outer diameter of the cutter head 9 is expanded and reduced. However, the spoke piece of a certain length is formed at the outer end of the spoke 9a. The cutter head 9 is set to an outer diameter substantially equal to the outer diameter of the skin plate 1 in the state where the spoke pieces are connected, and the outer diameter of the cutter head 4 is set to be the same when the spoke pieces are removed. You may comprise so that it may become a diameter which can be removed through the inside of a pipe line.

The simplified longitudinal section side view of the whole shield excavator. The longitudinal cross-sectional view of the arrangement | positioning part of a bending jack and a shield jack. The front view of a cutter head. The simplified vertical side view of the state which made the front-end surface of the skin plate contact the outer peripheral wall surface of the existing tunnel. The simplified vertical side view of the state where the soil removal means and the cutter head are removed and collected. A simplified longitudinal side view of a state where a tunnel is branched from an existing tunnel. The simple vertical side view of the shield excavator which shows another embodiment of this invention. The enlarged vertical side view of the principal part. The simplified vertical side view of the state which made the inner side hood contact | abut the existing tunnel. The simplified vertical side view of the state which made the front-end surface of the skin plate contact the outer peripheral wall surface of the existing tunnel. A simplified longitudinal side view of a state in which a cutter head or the like is removed and collected. The simplified longitudinal side view of the state where the tunnel is branched. The simple vertical side view of the shield excavator which shows another embodiment of this invention. The simplified vertical side view of the state which made the front-end surface of the skin plate contact the outer peripheral wall surface of the existing tunnel. A simplified longitudinal side view of a state in which a cutter head or the like is removed and collected. The simplified longitudinal side view of the state where the tunnel is branched. The simplified vertical side view which shows a prior art example. The simplified plan view.

Explanation of symbols

A Shield excavator T Existing tunnel
T 'branch tunnel P pipeline 1 skin plate 2 curved end face 3 outer cylindrical body 4 inner cylindrical body 5 hollow chamber 6 bent jack 7 shield jack 8 bulkhead 9 cutter head
16 Electa device

Claims (4)

  A shield excavator for constructing a branch tunnel that connects and communicates with an existing tunnel in a crossing manner toward the existing tunnel, and the front end surface of the skin plate that contacts the outer peripheral wall surface of the existing tunnel is connected to the outer periphery of the existing tunnel. A shield excavator for building a branch tunnel, characterized in that it is formed on a curved end surface curved in a concave arc shape on the side surface that can be joined to a wall surface.   The skin plate is provided with an outer cylindrical body integrally with a smaller diameter than the pipe line covering the excavation wall surface of the branch tunnel, with a small gap inward from the inner peripheral surface to the inner peripheral surface of the skin plate. The inner cylinder is inserted into the outer cylinder so as to be movable in the front-rear direction, and is detachably connected to the outer cylinder. Further, a front wall of the skin plate is attached to a partition wall provided integrally with the front portion of the inner cylinder. 2. A cutter head configured to excavate the ground and to be reduced in diameter so that the outer diameter is smaller than the inner diameter of the outer cylindrical body is supported rotatably. A shield excavator for building a branch tunnel as described.   The skin plate is composed of front and rear body portions that are refractorably connected to each other, and the inner and outer cylinders are also divided into a front tube portion and a rear tube portion that are also refractable to each other. 3. The shield tunnel excavation for building a branch tunnel according to claim 1, wherein a plurality of middle-folded jacks and shield jacks are arranged in an annular hollow chamber formed between outer peripheral surfaces. Machine.   The rear end of the skin plate is connected to the front end of the propulsion buried pipe in a refractionable manner, and is connected to the propulsion buried pipe in an annular hollow chamber formed between the inner peripheral surface of the skin plate and the outer peripheral surface of the outer cylindrical body. 3. A shield tunnel excavator for building a branch tunnel according to claim 1 or 2, wherein a plurality of middle-folding jacks for integrally bending the skin plate and the outer cylindrical body in a predetermined direction are attached. .

Images