JP4391386B2 - Obstacle removal method - Google Patents

Description

The present invention is to remove the safe and reliable obstacle even if there is obstacle such as H-section steel and steel sheet piles (sheet pile) regarding excavation for supporting Sawabutsu removing method tunnels excavation destination.

In recent years, along with the construction of drainage pipes and the like in urban civil engineering and sewerage works, there have been increased encounters with underground obstacles (obstacles such as H-shaped steel and steel sheet pile (sheet pile)). In this case, in general shield excavators (tunnel excavators), it is difficult to remove obstacles for the following reasons, so humans have to go out to the face and remove them directly by gas cutting etc. It was necessary to carry out high-risk work.
(1) If the obstacle during cutting moves, it may be entangled with the cutter head, and the shield excavator may not be able to dig and the bit may be lost.
(2) The fishtail cutter at the center of the cutter head is severely damaged.
(3) When an obstacle is cut with an ordinary earth and sand cutting cutter bit, it is chipped.
(4) When the obstructed piece is large, the shield excavator may become unable to dig up due to entanglement with the cutter head or screw conveyor.

  Therefore, recently, in Patent Document 1, a cutter head that rotates against a face is made up of a plurality of excavation bits, cutting bits, and protection bits arranged at intervals in the radial direction. It is arranged to cut the entire face by rotation, the cutting bit is formed in an arc shape concentrically with the cutter head, and arranged so that the excavation bit passes between the cutting bits adjacent in the radial direction. The shield bit is located on the rotation trajectory of the cutting bit, and the shield excavation is provided so as to be movable back and forth between a protection position where the tip is located in front of the cutting bit and a standby position located behind. A machine obstacle cutting device (and method) is disclosed.

  According to this, it is possible to cut the grooves (cuts) spaced in the radial direction on the obstacle by the cutting bit, and further, the obstacle which is easily broken due to the processing of the groove can be easily cut by the excavation bit. It can break and break into pieces that are smaller than the radial spacing of the cutting bits. Further, by moving the protective bit forward from the cutting bit, there are obtained advantages such that the wear of the cutting bit when the cutting bit is not used can be reduced.

  Further, in Patent Document 2, a cutter head comprising a plurality of ground excavation bits and a plurality of obstacle cutting bits that can be projected and retracted with respect to the ground excavation bits is used as a partition wall at the front end portion of the skin plate. A ring body is integrally provided on the outer periphery of the partition wall, and the ring body is fitted in the front end of the skin plate so as to be slidable back and forth, and the skin plate and the ring body are detachably fixed. Further, there is disclosed a shield excavator in which a locking means is disposed, and a partition propulsion mechanism is disposed on the inner peripheral surface of the skin plate on the rear side of the locking means.

  According to this, at the time of obstacle cutting, the obstacle cutting bit is reliably cut off by the obstacle cutting bit while the obstacle cutting bit is projected forward with respect to the ground excavation bit and the cutter head is advanced by the propulsion mechanism. be able to. At this time, since the obstacle can be cut and removed while only the cutter head is moved forward together with the partition wall, the cutter head rotates smoothly without shaking, and the obstruction cutting bit is not broken or damaged. Advantages such as being able to be used for a period of time and efficiently cutting off an obstacle with a relatively small driving force can be obtained.

  Further, in Patent Document 3, a cutter head is rotatably supported at a front portion of a tubular excavator body, and a plurality of earth and sand excavation cutter bits and a plurality of obstacle excavation cutter bits are provided on the front surface of the cutter head. There is disclosed a tunnel excavator in which the obstacle excavation cutter bit is shifted and arranged rearward in the excavation direction with respect to the earth and sand excavation cutter bit.

  According to this, during excavation of the earth and sand, the obstacle excavation cutter bit is restrained from being worn rearward, and when the ground changes from earth and sand to an advanced obstacle, the excavation direction front bit of the earth and sand excavation cutter bit is The obstacle excavation cutter bit can be excavated due to wear or loss, and the obstacle can be excavated with a simple structure. Advantages such as being able to continue excavation and improving workability can be obtained.

Japanese Patent Laid-Open No. 8-319798 JP 2000-104486 A JP 2002-47890 A

  However, in Patent Document 1 to Patent Document 3, a cutting bit, an obstacle cutting bit, a cutter bit for obstruction excavation, and a dedicated bit for obstruction cutting are provided, but the cutting bit is a saw-like shape. It is formed with a blade (Patent Document 1), and all the cutting angles of the obstacle cutting bit are acute angles (Patent Document 2), and the cutting bit of the obstacle excavation has a sharp angle at a part of the cutting edge (Patent Document). 3) Therefore, there was a difficulty in terms of durability. For example, when removing obstacles (flexible structures such as steel sheet piles) that are left and installed in soft ground in the ground, there will be obstacles to the shield external force (cutter torque: thrust) from the side. Since the deformation occurs together with the ground, the bit and the obstacle are touched while moving (vibrating) with each other during cutting, so the bit is easily lost.

  Further, in Patent Document 1, the cutting bit is formed in an arc shape concentrically with the cutter head, and is arranged so that the excavation bit passes between the cutting bits adjacent in the radial direction. It is possible to break into pieces smaller than the direction interval, but such a radial interval of the bit is still insufficient, and the cut obstacle pieces get entangled with the cutter head and screw conveyor, and the shield excavator There is still a risk of getting stuck.

The present invention has been made to solve such a problem, provides a safe and reliable obstacle to be removed can excavate the tunnel of supporting Sawabutsu removing method as well as equipped with a high obstacle cutting bit durability The purpose is to do.

The obstruction removal method of the present invention for achieving the above-described object includes a front part of a cutter head that is rotatably supported by a cutter head at a front portion of a tubular excavator body and is tapered in a tapered cone shape. Provided with a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits, and using a tunnel excavator with an obtuse tip end angle of the obstacle cutting bits, A fishtail cutter passage portion at the center of the cutter head in the ground is drilled in advance .

In addition, a cutter head is rotatably supported at the front portion of a cylindrical excavator main body, and a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits are provided on a tapered conical inclined front portion of the cutter head. When the obstacle cutting bit is removed by using a tunnel excavator in which the tip end angle of the tip is made obtuse and the path adjacent to the cutter head in the radial direction is wrapped, is disposed. The fishtail cutter passage portion at the center of the cutter head in the obstacle and the ground is drilled in advance .

In addition, a cutter head is rotatably supported at the front portion of a cylindrical excavator main body, and a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits are provided on a tapered conical inclined front portion of the cutter head. The obstruction cutting bit has an obtuse tip tip angle and is formed in a mountain shape or arc shape symmetrical to the cutting direction, so that one bit can handle both left and right rotation of the cutter head. When the obstacle at the excavation site is removed using the existing tunnel excavator, the fish tail cutter passage portion at the center of the cutter head in the obstacle and the ground is drilled in advance .

In addition, a cutter head is rotatably supported at the front portion of a cylindrical excavator main body, and a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits are provided on a tapered conical inclined front portion of the cutter head. The obstruction cutting bit is formed in a chevron shape or an arc shape symmetrical with respect to the cutting direction, with the tip end angle of the tip being an obtuse angle and a path adjacent to the cutter head in the radial direction wrapped. When using a tunnel excavator that can handle both left and right rotation of the cutter head with a single bit, when the obstacle at the excavation site is removed, it passes through the fish tail cutter in the center of the cutter head on the obstacle and the ground. It is characterized by drilling a hole in advance.

    In addition, after the drilling, an auxiliary method for fixing the obstacle so as not to move is constructed.

  According to the obstacle removing method of the present invention, the durability of the fishtail cutter can be increased. In addition, by constructing an auxiliary method such as ground improvement, the durability of the obstacle cutting bit can be further improved and the obstacle can be removed safely and reliably.

It will be described in detail with reference to the drawings by the engagement Ru supported Sawabutsu removing method of the present invention embodiment.

  FIG. 1 is a side view of a shield excavator as a tunnel excavator showing an embodiment of the present invention, FIG. 2 is a perspective view of a cutter head, FIG. 3 is an explanatory diagram of an obstacle cutting bit and an earth and sand cutting bit, and FIG. Is a locus diagram of each obstacle cutting bit, FIG. 5 is an arrangement diagram of the obstacle cutting bit, FIG. 6 is a shape comparison diagram of the cutter head, FIG. 7 is an explanatory diagram of drilling holes, FIG. 8 is a construction diagram of ground improvement, FIG. Fig. 10 is an explanatory diagram of the improvement strength, Fig. 10 (a) is a schematic diagram of obstacle removal, Fig. 10 (b) is a ground improvement calculation model diagram, and Fig. 11 is a ground improvement range ( It is sectional drawing of a depth direction.

  As shown in FIG. 1, in the shield excavator 10 of this embodiment used for tunnel excavation work, a bulkhead 12 is formed in the front portion of a tubular excavator main body 11, and a ring is formed on the bulkhead 12. A rotating body 14 is rotatably supported by a geared bearing 18, and an inclined cutter head 15 in which a cutter face plate 16 and a cutter pork 17 (a front portion of the cutter head) described later are inclined in a tapered cone shape. Is installed. A seal 13 is provided between the rotating body 14 and the excavator body 11 to prevent foreign matters such as earth and sand from entering the meshing portion of the gear.

  The above-described bearing 18 with a ring gear is fixed to the rear part of the cutter head 15 and the rotating body 14, while a driving motor 19 is mounted on the excavator body 11, and the driving gear 20 of the driving motor 19 is a bearing with a ring gear. It meshes with 18 ring gears. Therefore, when the drive motor 19 is driven to rotate the drive gear 20, the cutter head 15 can be rotated via the bearing 18 with the ring gear and the rotating body 14.

  On the other hand, a screw conveyor 21 is disposed in the excavator main body 11, and the front end portion passes through the bulkhead 12 and communicates with the chamber 22. In addition, a plurality of shield jacks (not shown) are arranged in parallel along the circumferential direction on the inner peripheral surface of the excavator main body 11, and an erector device (not shown) for assembling a segment is disposed at the rear part thereof. Therefore, when this shield jack extends rearward in the digging direction and presses against the existing segment, the excavator main body 11 can be advanced by the reaction force, and the excavator main body 11 in which the erector device has advanced and the existing segment Segments can be assembled in the empty space.

  In FIG. 1, reference numeral 23 denotes a fishtail cutter (consisting of a number of preceding cutter bits) attached to the tip of the center shaft 24, and 25 is built in the cutter head 15 and can be protruded to the outer peripheral side by an extrusion jack 26. It is a copy cutter.

  As shown in FIG. 2, the cutter head 15 includes two cutter spokes 17 and a cutter face plate 16 supported by a center shaft 24 and an outer ring 27 at a point-symmetrical position, and earth and sand cutting is performed on both sides of each cutter pork 17. A number of obstacle cutting bits 31 for attaching spokes are mounted in the center of the bit 30, and a number of obstacle cutting bits 32 for mounting face plates are mounted on each cutter face plate 17. A plurality of obstacle cutting bits 33 for attaching the outer peripheral portion are mounted on the outer peripheral ring 27 and each cutter face plate 17.

As shown in FIG. 3, the earth and sand cutting bit 30 has a sharp tip end angle with a planed carbide tip 30 a having a predetermined rake angle α ₁ and a clearance angle β (FIG. 4). (See (a)). On the other hand, the obstacle cutting bit 31 for attaching the spoke is formed in a mountain shape symmetrical with respect to the cutting direction (circumferential direction of the cutter head 15) around one (or a plurality of) carbide tips 31a. Compared to the carbide tip 30a of the cutting bit 30 for cutting, the rake angle α ₂ is negative, and it can be said that the tip end angle is an obtuse angle (see FIG. 4B). Further, the obstacle cutting bit 32 for attaching the face plate and the obstacle cutting bit 33 for attaching the outer peripheral portion are embedded with a plurality of (five in the illustrated example) carbide tips 32a (33a) at predetermined intervals in the cutting direction. However, it is formed in an arc shape symmetrical to the cutting direction, and the rake angle is negative and the tip end angle is obtuse as in the obstruction cutting bit 31 for attaching the spoke (FIG. 4 ( c)). The obstacle cutting bit 33 for attaching the outer peripheral portion is obtained by dividing the obstacle cutting bit 32 for attaching the face plate into two in the radial direction of the cutter head.

  As shown in FIGS. 4 and 5, the obstacle cutting bit 31 for attaching the spoke, the obstacle cutting bit 32 for attaching the face plate, and the obstacle cutting bit 33 for attaching the outer peripheral portion are adjacent to each other in the radial direction of the cutter head 15. It is placed in a way that wraps with a matching path so that there is no gap between the bits. In the illustrated example, the outer peripheral portion and the cutter face plate 16 are arranged so as not to have a gap, and the positional relationship on the cutter face plate 16 and the cutter pork 17 is arranged, for example, by being shifted by a half pitch as shown in FIG. . In FIG. 5, C indicates a bit mounting position from the center of the cutter head, Wb indicates a bit arrangement interval, and Wa indicates a bit width.

  Accordingly, in order to excavate a tunnel with the shield excavator 10 configured as described above, as shown in FIG. 1, when a plurality of shield jacks are extended while the cutter head 15 is rotated by the drive motor 19, an existing segment is formed. The excavator main body 11 moves forward due to the reaction force that is pressed against, and the fishtail cutter 23, the earth and sand cutting bit 30, and the obstacle cutting bits 31, 32, and 33 located in the foremost position excavate the front ground. The excavated earth and sand are taken into the chamber 22 and discharged to the outside by the screw conveyor 21. Thereafter, any one of the shield jacks is operated in the contracting direction to form a space with the existing segment, and a new segment is mounted in this space by an erector device. By repeating this work, the tunnel is continuously excavated and formed.

  During this excavation, as shown in FIG. 6, when an obstacle S such as H-shaped steel or steel sheet pile (sheet pile) is encountered, the shape of the cutter head 15 and the obstacle cutting bits 31, The obstacle S can be effectively cut by the shapes and arrangements of 32 and 33.

  In other words, the cutter head plate 16 and the cutter pork 17 are inclined in a conical shape (for example, 5 ° to 10 °), and the cutter head 15 is not inclined (see FIG. 6A) (see FIG. 6). Compared to (b)), the obstacle cutting range A becomes smaller, and the cutting resistance can be reduced.

  Further, the tip end angle of each obstacle cutting bit 31, 32, 33 is an obtuse angle, and is formed in a chevron shape or an arc shape symmetrical to the cutting direction (the circumferential direction of the cutter head 15). Since the head 15 can handle both left and right rotations, cutting efficiency and durability are higher than a general earth and sand cutting bit.

In addition, each obstacle cutting bit 31, 32, 33 is arranged so as to wrap with a path adjacent to the cutter head 15 in the radial direction so that there is no gap between the bits.
The obstacle S can be cut as small as possible, and the cut piece can be discharged quickly and smoothly by the screw conveyor 21.

  In the present embodiment, when it is known in advance that the obstacle S is present at the excavation destination, as shown in FIG. 7, the fish tail cutter 23 passage portion of the cutter head 15 in the ground and the obstacle S is the start shaft. A horizontal boring 41 installed at 40 is drilled in advance. In the illustrated example, a fishing rod system composed of three drilled pipes P1, P2, and P3 having different pipe diameters is adopted, and the construction is performed by gradually changing the pipe diameter from a large one to a small one.

  Furthermore, as shown in FIG. 8, the ground improvement of the omnidirectional high-pressure injection system is applied as an auxiliary method, the ground around the obstacle S is improved, and the obstacle S is fixed. For this purpose, it is necessary to drill the obstacle S in advance by the horizontal boring 41 (see FIG. 7) and insert a large number of perforated pipes P4 up to the final improved position of the high-pressure injection method. In FIG. 8, “a” indicates the ground improvement range, “b” indicates the tunnel, and “c” indicates the high-pressure injection region by the porous tube P4.

  At this time, as shown in FIG. 9, first, the physical characteristics and mechanical characteristics of the target ground are grasped, the shield plan and the position of the obstacle are confirmed, and then the geometric dimensions and physical mechanics of the material are confirmed. After satisfying the design conditions of setting the cutter torque value and cutting speed that can cut the target obstacle, the improvement strength required from the cutter torque as the setting of improvement strength and improvement range ... Calculate (1) and the improvement strength (2) determined from the allowable displacement of the obstacle to ensure cutting and the improvement range (3) in the depth direction.

Next, an example of the calculation methods (1) to (3) will be shown below.
(1) Improved strength determined by cutter torque value Maximum torque required to cut steel, etc. Tc (kN · m)
Turning radius r (m)
Obstacle cutting bit Number n Cross section a (m ² )
Strength required for ground improvement qc = Tc / r / (n · a) (kN / m ² )
Safety factor n (consultation depending on site conditions)
Design improvement strength qa = n · qc (kN / m ² )

(2) Improved strength determined by the allowable displacement allowed for obstacles The calculation theory of the amount of displacement generated by shield external force on obstacles is shown below.
The allowable value of the generated displacement amount is determined from various conditions such as the excavation speed.
Basically, the generated displacement is 1 cm or less.
The displacement model generated in the obstacle is calculated by the “beam model on the elastic floor” based on various conditions shown in FIG.
Where EI: (for example, bending stiffness of steel sheet pile)
L: Obstacle burial length (m)
Lu: Depth (m) from the top of the obstacle to the ground improvement body (top)
B1: Upper improved thickness from the top of shield excavator (m): Normal 1.0m
D: Outer diameter of shield excavator (m)
B2: Lower part thickness from the top of shield excavator (m): Normally 1.0m
Ls: Depth from obstacle lower end to ground improvement body (lower end) (m)
kHs: Ground reaction force coefficient of improved ground (kN / m ³ ) (B1 + D + B2) section
kH ₀ : Ground reaction force coefficient of unmodified ground (kN / m ³ ) Upper ground from shield outer diameter
kH ₁ : Ground reaction force coefficient of unmodified ground (kN / m ³ ) Lower ground than shield outer diameter
Ns: Shield horizontal external force acting on obstacles (kN / m ² )
Qs: Shield normal external force acting on an obstacle (kN / m ² )
Ms: Shield moment (torque) external force (kN · m) acting on the obstacle
The beam boundary condition of the “beam model on elastic floor” is input according to the field situation.

(3) Depth direction improvement range setting As shown in Fig. 11, the improvement range in the depth direction is as follows: shield excavator outer diameter lower end: B2 lower end, passive collapse angle (45-φ / 2) ° on the ground and shield Excavator outer diameter upper end: The range up to the intersection where the horizontal line is drawn from the upper end of B1 is the improvement range in the depth direction.
(When clay soil, internal friction angle φ = 0, depth improvement width is square of B1 + D + B2)
(When the internal friction angle can be taken into account, it becomes as long as (45−φ / 2) °.)

  In this way, in this embodiment, when it is known that the obstacle S is present in advance at the excavation destination, the ground and the obstacle S are cut in advance through the fish tail cutter 23 passing portion of the cutter head 15. Therefore, damage to the fishtail cutter 23 is reduced. Further, since the obstacle S is fixed so as not to move due to the ground improvement, it is possible to prevent the obstacle S from moving and entangled with the cutter head 15 so that the shield excavator 10 cannot dig and the bit is lost.

  Therefore, the obstacle S can be removed safely and reliably by the synergistic effect of the shape of the cutter head 15 and the shape and arrangement of the obstacle cutting bits 31, 32, 33 as described above. The present embodiment can also be used for a relatively small diameter tunnel excavator having an outer diameter of about 270 cm that does not have a facility or work space for removing the obstacle S in the excavator body 11. is there.

  Needless to say, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention. For example, other than ground improvement may be employed as an auxiliary construction method for changing the shape and arrangement of the obstacle cutting bits 31, 32, 33 and fixing the obstacle S. Moreover, although the horizontal construction by the horizontal boring 41 was used as the solidification method by ground improvement, you may use the vertical (vertical) construction by a vertical (vertical) boring.

It is a side view of the shield excavator as a tunnel excavator which shows one Example of this invention. It is a perspective view of a cutter head. It is explanatory drawing of the obstruction cutting bit and the earth and sand cutting bit. It is a locus diagram of each obstacle cutting bit. It is an arrangement plan of an obstacle cutting bit. It is a shape comparison figure of a cutter head. It is drilling explanatory drawing. It is a construction drawing of ground improvement. It is a setting flow of the construction range of ground improvement. In the explanatory diagram of the improved strength, FIG. (A) is a schematic diagram of obstacle removal, and (b) is a ground improvement calculation model diagram. It is sectional drawing of a ground improvement range (depth direction).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Shield excavator, 11 Excavator main body, 12 Bulk head, 13 Seal, 14 Rotating body, 15 Cutter head, 16 Cutter face plate, 17 Cutter pork, 18 Bearing with ring gear, 19 Drive motor, 20 Drive gear, 21 Screw conveyor , 22 chamber, 23 fish tail cutter, 24 center shaft, 25 copy cutter, 26 extrusion jack, 27 outer ring, 30 earth and sand cutting bit, 31 spoke mounting obstacle cutting bit, 32 face plate mounting obstacle cutting bit, 33 Obstacle cutting bit for outer peripheral mounting, 30a, 32a, 33a Carbide tip, 40 start shaft, 41 horizontal boring, P1, P2, P3 drilling pipe, P4 perforated pipe, b ground improvement range, ro tunnel, c high pressure injection Zone, S obstacle.

Claims (5)

A cutter head is rotatably supported at the front portion of the excavator body having a cylindrical shape, and a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits are provided on a tapered conical inclined front portion of the cutter head, When removing obstacles at the excavation destination using a tunnel excavator with the tip end angle of the obstacle cutting bit being obtuse, drill holes ahead of the fish tail cutter passage at the center of the cutter head in the obstacle and the ground. Obstacle removal method characterized by keeping . A cutter head is rotatably supported at the front portion of the excavator body having a cylindrical shape, and a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits are provided on a tapered conical inclined front portion of the cutter head, The obstacle cutting bit has an obtuse angle at the tip of the tip, and when the obstacle at the drilling site is removed by using a tunnel excavator arranged by wrapping the adjacent one in the radial direction of the cutter head , An obstruction removal method characterized by drilling a fish tail cutter passage portion at the center of a cutter head in an object and ground in advance . A cutter head is rotatably supported at the front portion of the excavator body having a cylindrical shape, and a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits are provided on a tapered conical inclined front portion of the cutter head, tunnel that is left of the cutter head, and can correspond to the right two rotary formed symmetrically mountain-shaped or arc-shaped in the cutting direction by one bit with the obstacle cutting bit to the tip point angle and obtuse when removing the excavation target obstacle by using the excavator, obstacle and the obstacle removing method which is characterized in that it drilled prior to fishtail cutter passage of the central cutter head in the ground. A cutter head is rotatably supported at the front portion of the excavator body having a cylindrical shape, and a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits are provided on a tapered conical inclined front portion of the cutter head, The obstruction cutting bit has an obtuse tip end angle, and is placed by wrapping the adjacent ones in the radial direction of the cutter head, and is formed in a chevron or arc shape symmetrical to the cutting direction. When removing the obstacle at the excavation destination using a tunnel excavator that can handle both left and right rotation of the cutter head with two bits, the fish tail cutter passage part in the center of the cutter head on the obstacle and the ground Obstacle removal method characterized by drilling in advance. After the drilling, claim 1, 2, 3 or 4 obstacle removing method according to, characterized in that applying a supplementary method for fixing immovably the obstacle.

Images