JP4547553B2 - Shield digging method and shield digging machine - Google Patents

Description

  The present invention relates to a shield machine for constructing tunnels, sewers, and other tunnels (hereinafter collectively referred to as “excavations”), for example, excavations having a rectangular cross section.

  A shield machine that builds an excavation mine on a natural ground (same as the ground) has as its basic components an excavation part for excavating the natural ground, and a cylindrical main body with an excavation part installed on the front surface. A cylindrical tail portion that is extended to the rear end of the main body and is externally integrated with the main body, and a segment assembling means that assembles the segments into a cylindrical shape to form a segment cylindrical body (for a segment elector or an elector device). The same), an extruding means that takes the reaction force on the segment cylindrical body and advances the main body by the reaction force (same as the shield jack), and a tail seal means that seals the gap between the segment cylindrical body and the tail portion. And a back material injection means for injecting the back material into the gap between the segment tubular body and the excavation mine, and a soil discharge means for discharging the excavated earth and sand to the outside of the machine.

  The shield machine disclosed in Patent Document 1 has a drum cutter whose excavation part is supported by a gear box and includes a rotation shaft orthogonal to the excavation direction, and the front side of the gear box is U-shaped in plan view. The center small drum cutter is supported on the inside, the side large drum cutter is supported on the outside, and the outside itself is accommodated in the side large drum cutter. Therefore, it is possible to form an excavation mine having a width substantially equal to the width of the main body, particularly an excavation mine having a rectangular cross section.

  The shield excavator disclosed in Patent Document 2 includes a left and right drum cutter having a rotation axis orthogonal to the excavation direction supported by a tiltable swing beam and a rotation axis parallel to the excavation direction. A central drum cutter. This makes it possible to form a drilling pit that is approximately the same as or wider than the main body, facilitating the intake and discharge of excavated soil, and facilitating correction of the direction of excavation, sharp curve construction, and tunnel gradients. Can be.

  On the other hand, in order to maintain or improve the reliability of the constructed excavation pit (same as the reliability of the installed segmented tubular body), depending on the properties of the ground where the excavation mine is constructed, or when the ground needs to be improved Additional construction may be required. For example, in Patent Documents 3 to 5, a tunnel structure is formed by excavating a rectangular vertical cross-sectional pile using a shield machine, and then construction work such as earth retaining and water stop under the tunnel structure is performed. Techniques for performing are disclosed.

JP-A-2-66295 (page 3, FIG. 1) JP-A-4-131494 (page 3-4, FIG. 1) JP-A-8-28197 (page 4, FIG. 2) JP-A-8-28198 (page 4, FIG. 2) JP-A-8-28199 (page 4, FIG. 2) Japanese Patent Laid-Open No. 4-327697 (page 2-3, FIG. 1)

(Ah) However, the injection of the backing material in the shield machine is intended to fill the gap between the segment tubular body and the excavation mine. It is not intended to stabilize the excavation pit.
(Ii) Since the technique disclosed in Patent Document 1 cannot form an excavation pit larger than the height of the main body part of the shield machine, there is no gap in the lower part of the main body part, and the ground improving agent in the gap There was a problem that the improved ground could not be formed by feeding, filling with improved soil, or other methods. In other words, this technique does not form an improved ground below the segment in the process of shield excavation that advances the main body forward.

  (U) According to the technique disclosed in Patent Document 2, the lower part of the main body of the shield machine can be excavated with a width substantially equal to or wider than the main body. However, it is intended to facilitate the intake and discharge of excavated soil, correction of the direction of excavation, the construction of sharp curves and the ease of adapting to tunnel gradients, not for the purpose of soil improvement at the bottom of the segment. Absent. Moreover, if the lower part of the main body part of the shield machine is excavated with a width substantially equal to or wider than the main body part, the main body part is supported by the excavated ground, so it is difficult to maintain an appropriate posture. Therefore, there was a problem that the direction of excavation was not stable.

  (E) The technologies disclosed in Patent Documents 3 to 5 are for improving the ground such as pile driving, earth retaining, water stop, etc. from the inside of the tunnel after forming the tunnel structure. It does not form an improved ground at the bottom. Therefore, when the pile structure is formed from the pit after the tunnel structure is formed, earth retaining, water stoppage, etc., the existing segment is destroyed or removed, and the ground is removed by removing the lid provided on the existing segment. It is necessary to expose the inside of the mine, and if the ground is inadvertently exposed, there will be dangers and obstacles such as earth and sand and groundwater erupting into the mine, making it difficult to improve the ground itself. There was a problem of being invited.

  (O) In the cast-in-place lining method in which concrete is directly placed in place of an existing segment by a shield machine, there is a problem that the ground below the lining concrete cannot be improved (for example, patents) Reference 6).

  The present invention has been made to solve such a problem, and can improve the ground below the segment while shield digging, maintain the posture of the main body of the shield digging machine properly, and the digging direction Is necessary to stabilize the formed segment, and hence the excavation mine, and to reduce the work load related to ground improvement after the excavation mine is formed (sometimes, such post-operation is unnecessary). However, it is an object of the present invention to provide a shield excavation method and a shield excavator that can suppress the occurrence of dangers and failures due to the work as much as possible.

The first aspect of the shield digging method according to the present invention is a shield digging that excavates the front surface of a cylindrical main body, takes a reaction force on a cylindrical segment disposed behind the main body, and advances the main body forward. In this process, the excavated ground area (hereinafter referred to as “excavated ground”) is formed by excavating the lower part of the front surface of the main body, and the ground improvement agent is fed into the excavated ground to improve the lower part of the segment. The width of excavating the lower part of the front surface of the main body is narrower than the width of the front surface of the main body.

Further, the second aspect of the shield excavation method according to the present invention excavates the front surface of the main body portion formed in a cylindrical shape, and applies a reaction force to the segment formed in the cylindrical shape toward the rear of the main body portion. In the process of shield excavation that advances the main body part forward by a predetermined distance, the lower part of the front surface of the main body part is excavated, and the ground improvement agent is fed into the excavation ground formed in the lower part of the main body part to a forms a improved ground at the bottom of the segment extruded toward the width drilling a lower portion of the front surface of the body portion, and wherein the narrower than the width of the front surface of the main body portion.
Furthermore, the third aspect of the shield digging method according to the present invention includes a step of excavating a front surface of the main body portion formed in a cylindrical shape, and a step of excavating a lower portion of the front surface of the main body portion at a predetermined position. A reaction force is applied to a segment formed in a cylindrical shape toward the rear of the main body, and the main body is advanced forward by a predetermined distance; and a ground improver is added to the excavation ground formed at the lower portion of the main body. A step of excavating the front surface, a step of excavating the lower portion, a step of proceeding forward, and a step of feeding the ground improvement agent. An improved ground having a predetermined distance is formed at a lower portion of the segment, and a width of excavating a lower portion of the front surface of the main body is smaller than a width of the front surface of the main body.

  In each aspect of the shield excavation method according to the present invention, when the improved ground is formed at the lower part of the segment (when the ground improver is fed into the excavated ground formed at the lower part of the main body part and the bottom surface of the main body part and the above-mentioned Any position along the direction of digging (including the forward direction of the main body and the backward direction of the main body). Therefore, the improved ground may be formed only at a predetermined position or a predetermined distance, or may be formed continuously, intermittently or discontinuously. Similarly, when excavating the lower part of the front surface of the main body part, it is possible to excavate any position along the direction of the excavation, so that only a predetermined position or a predetermined distance may be excavated, or continuous or intermittent Or you may excavate discontinuously.

The first aspect of the shield machine according to the present invention is to apply a reaction force to a cylindrical main body part, excavation means for excavating the front surface of the main body part, and a cylindrical segment arranged behind the main body part. An extruding means for advancing the main body part forward and an earth discharging means for discharging the excavated earth and sand, and the excavating means can freely form a groove excavating ground below the main body part, and the groove excavating ground The ground improvement agent feeding means for feeding the ground improvement agent to the base is provided, and thereby the improved ground is formed in the lower part of the segment in the process of moving the main body forward by the pushing means.
Further, the second aspect of the shield machine according to the present invention is opposite to the cylindrical main body portion, the excavating means for excavating the front surface of the main body portion, and the cylindrical segment disposed behind the main body portion. It is equipped with an extruding means that takes the force and advances the main body part forward, and a soil discharging means that discharges the excavated earth and sand, and the improved soil is formed in a gap formed between the bottom surface of the main body part and the bottom surface of the segment. Improved soil filling means for filling the body, thereby forming an improved ground at the lower portion of the segment in the process of moving the body portion forward by the pushing means , and at this time, the body portion extends to the skin plate and the skin plate. The improved soil filling means is characterized in that the improved soil filling means fills the gap formed between the outer mold frame installed inside the tail plate and the bottom surface of the segment.

A second aspect of the shield machine according to the present invention includes a main body portion formed in a cylindrical shape by a skin plate, a support arm protruding forward of the main body portion, and supported by the support arm and orthogonal to the excavation direction. Excavating means having a rotating shaft, a drive motor installed on the main body and generating rotational force, and a rotational force installed on the support arm and transmitting the rotational force generated by the drive motor to the excavating means A shield excavator comprising a transmission mechanism, an extrusion means that takes a reaction force on a segment toward the rear of the main body portion, and advances the main body portion forward, and a soil discharge means that discharges excavated earth and sand, The excavating means is capable of forming a groove excavating portion below the main body.
Moreover, the 3rd aspect of the shield machine which concerns on this invention is equipped with the ground improvement agent sending means which sends a ground improvement agent to the excavation part formed in the lower part of the said main-body part in the 2nd aspect . Features.

According to a fourth aspect of the shield machine according to the present invention, in the third aspect, the excavation means includes a center small drum cutter and a side large drum cutter disposed so as to sandwich the center small drum cutter. The support arm is a gear box, the rotational force transmission mechanism is constituted by a gear train, and after the rotational force is transmitted forward, it is guided into the large side drum cutter, In the large side drum cutter, the large side drum cutter is divided into a side rotational force for rotating the large side drum cutter and a central rotational force for rotating the small center drum cutter.
Further, a fifth aspect of the shield machine according to the present invention is the fourth aspect , wherein the side large drum cutter includes a center-side drum having a cutter bit installed on the outer peripheral surface, and a cutter bit on the outer peripheral surface. It has an installed side-side drum, and drum expansion / contraction means for changing the distance in the rotation axis direction between the center-side drum and the side-side drum.

A sixth aspect of the shield machine according to the present invention, in its second or third aspect of the excavation means, the center large drum cutters and side small drum disposed so as to sandwich the center large drum cutter The support arm is a gear box, the rotational force transmission mechanism is constituted by a gear train, and after the rotational force is transmitted forward, it is guided into the center large drum cutter, Further, the center large drum cutter is divided into a center rotational force for rotating the center large drum cutter and a side rotational force for rotating the side small drum cutter.
According to a seventh aspect of the shield machine according to the present invention, in any one of the second to sixth aspects, the support arm is tiltable in the vertical direction.
Furthermore, an eighth aspect of the shield machine according to the present invention includes a main body portion formed in a cylindrical shape by a skin plate, a tail plate continuously extending from the skin plate to the rear of the main body portion, A support arm projecting forward of the main body, a excavating means supported by the support arm and including a rotating shaft orthogonal to the digging direction, a drive motor installed in the main body and generating a rotational force; A reaction force is applied to the rotational force transmission mechanism that is installed on the support arm and transmits the rotational force generated by the drive motor to the excavating means and the segment formed at the rear of the main body, and the main body is advanced forward. An extrusion means, and a soil discharge means for discharging the excavated earth and sand, the outer mold frame installed inside the tail plate, and the outer mold frame and the lower surface of the formed segment. while A gap formed, and further comprising a modified soil filling means for filling the improved soil rearward.

  In each aspect of the shield machine according to the present invention, the improved ground forming means (including the ground improver feeding means and the improved soil filling means) is used when the improved ground is formed in the lower part of the main body. Can be formed at any position along the line, so that the improved ground can be formed only at a predetermined position or a predetermined distance, and can also be formed continuously or intermittently or discontinuously. Further, when the excavation means forms the groove excavation ground at the lower part of the main body, it can form the excavation ground at an arbitrary position along the excavation direction, and therefore the excavation ground can be formed only at a predetermined position or a predetermined distance. It can be formed continuously or intermittently or discontinuously.

According to the first aspect of the shield excavation method according to the present invention, the ground improver can be fed while the shield excavation is performed, and the ground under the segment can be improved. Each of the shield excavation method and the shield excavator according to the present invention According to the 4th aspect, improved soil can be sent back, excavating a shield, and the ground below a segment can be improved. Therefore, the formed segment and thus the excavation pit can be stabilized. In addition, since ground improvement can be completed in advance before excavation pit formation, work related to ground improvement such as pile driving, earth retaining, water stoppage, etc. that has been done after the excavation mine has been formed And the like, including the work of providing an injection hole for injecting the ground and a pressurizing means for infiltrating the ground conditioner into the unexcavated ground), and the load can be reduced. It is possible to suppress as much as possible the occurrence of dangers and failures resulting from the work.

  In addition to the above effects, according to each aspect of the shield excavation method and shield excavator according to the present invention, the following effects can be obtained.

Further, in the first aspect of the shield excavation method according to the present invention, when the ground improver is fed to the excavation site when excavating the lower part of the front surface of the main body, stirring and mixing with the excavated ground becomes easy. The ground improvement of the lower part of a part and the formed segment can be performed reliably. For this reason, the stability of the segment and the excavation mine is further improved, and the necessity and load of the work related to the ground improvement performed after the formation of the excavation mine can be remarkably reduced (in some cases, the work itself is unnecessary). Even if such a post-operation is necessary, it is possible to more reliably suppress the occurrence of danger or failure due to the operation.

Further, according to the first aspect of the shield machine according to the present invention, since the ground improving agent can be fed into the groove excavation ground, the excavation ground can be freely used, and the lower part of the main body portion or the segment can be arbitrarily set. This can be formed at the position. Furthermore, since the width of the trench excavation ground is narrower than the width of the front surface of the main body, the main body is stably supported by the ground in the area other than the excavation ground in the excavation pit, and the excavation direction varies. Nor.

According to a third aspect of the shield method and shield machine according to the present invention, it can be formed repeatedly digging ground of the groove strip, since the formed drilling soil can feed the soil improvement agent, excavation direction The improved ground can be formed at any position along the road, the improved ground can be formed only at a predetermined position or a predetermined distance, and can be formed continuously, intermittently or discontinuously.

According to each aspect of the fourth to seventh shield machine according to the present invention, it is possible to concretely realize the second aspect of the excavator, and more particularly drilling ground groove strip at the bottom of the body portion It is possible to realize an excavator equipped with excavation means that can freely form the lower part or the lower part of the segment.
In particular, according to the fourth aspect of the shield machine according to the present invention, when the support arm is projected in the digging direction within the projected area when the center small drum cutter and the side large drum cutter are projected in the digging direction. Therefore, it is possible to excavate without causing any excavation residue in the width direction, and it is possible to eliminate or minimize the range in which the unexcavated natural ground directly collides with the support arm.
According to the fifth aspect of the excavator, the side large drum cutter includes the center-side drum and the side-side drum, and the distance between the two is freely changeable, so that the width of the groove excavation part is appropriately set. Can do.
Further, according to the sixth aspect of the excavator, the projection area when the support arm is projected in the excavation direction is within the projection area when the center large drum cutter and the side small drum cutter are projected in the excavation direction. Since it is generally accommodated, excavation can be performed without causing any excavation residue in the width direction, and the range in which the unexcavated portion directly collides with the support arm can be eliminated or minimized.
Further, according to the seventh aspect of the excavator, since the support arm is tiltable in the vertical direction, the excavation part can be formed in the lower part of the main body part only at a predetermined position in the excavation direction, With a drum cutter having a relatively small diameter, a wide range can be excavated in the vertical direction.

According to the 8th aspect of the shield machine which concerns on this invention, when a main-body part is formed with the skin plate and the tail plate extended in the skin plate, the outer formwork installed inside the tail plate Since the improved soil is press-fitted or filled in the gap formed between the bottom of the segment and the bottom surface of the segment, the improved soil is surely filled in the lower portion of the segment. Thereby, the main body of the shield machine is stably supported on the ground, and fluctuations in the excavation direction can be suppressed as much as possible, while the formed segment is reliably supported by the improved soil. Since the reaction force is applied to this segment, the propulsion of the main body is further stabilized.

  In the following description, a direction that is substantially orthogonal to the digging direction and that is in the horizontal direction or substantially horizontal direction is referred to as a width direction, and a direction that is substantially orthogonal to the digging direction on the vertical plane and that is vertical or substantially vertical. What is in is called the height direction. The direction of rotation around an axis parallel to the width direction is originally called the circumferential direction. However, in the following explanation, in view of the fact that the component in the height direction also fluctuates, this is the vertical direction. That's it.

[Embodiment 1]
(Shield machine)
1 to 3 show a front portion of a shield machine according to Embodiment 1 of the present invention. FIG. 1 is a sectional view in side view, FIG. 2 is a sectional view in plan view, and FIG. FIG.
1 to 3, the shield machine 1 includes a main body 10 that is formed into a cylindrical shape having a rectangular cross section by a skin plate, and a support arm 20 that projects forward of the main body 10 (left side in FIGS. 1 and 2). The excavating means (hereinafter referred to as “drum cutter”) 30 is supported by the support arm 20 and has a rotating shaft arranged in the horizontal direction, and is installed in the main body 10 to generate a rotating force and to generate the rotating force in the drum. A rotation mechanism 40 for transmitting to the cutter 30, a tilting means 50 for tilting the support arm 20 in the vertical direction, and a ground improver feeding means 60 for feeding a ground improver to the lower part of the main body 10.

(Main body)
The main body 10 is a cylindrical body formed by a skin plate 11, and a bulkhead 12 is installed at one end (hereinafter referred to as “front end”). The bulkhead 12 is formed with a substantially concave recess 13 in plan view, and a support arm 20 is installed in the recess 13. Further, the bulkhead 12 is provided with a soil discharge opening 14, and a screw conveyor 15 (collectively referring to a screw and a steel pipe for storing the screw) as a soil discharge means is installed in the soil discharge opening 14. ing.

Further, at the rear part of the main body part 10, a reaction jack is applied to the segment cylindrical body 6 formed on the rear side, and a shield jack 16 which is an extrusion means for advancing the main body part 10 forward, and the segment is a segment cylindrical shape having a rectangular cross section An erector apparatus (not shown) for assembling the body 6 and a backing material injection means (not shown) for injecting the backing material into the gap between the segment cylindrical body 6 and the excavation pit are installed.
A tail plate 17 extends behind the skin plate 11. That is, the tail plate 17 is formed so as to extend rearward from the skin plate 11. As a result, a cylindrical tail portion is formed which is integrated with the main body portion. A tail seal 18 is installed on the inner surface of the tail plate 17, and the tail seal 18 is in contact with the segment cylindrical body 6 disposed inside the tail portion. Thereby, the inside of the main-body part 10 is maintained watertight.

(Support arm)
The support arm 20 includes a lower support arm 20a, an intermediate support arm 20b, and an upper support arm 20c. The lower support arm 20a can rotate within a limited range around the width direction axis, and thus can be tilted up and down, while the middle support arm 20b and the upper support arm 20c rotate about the width direction axis. Impossible, and therefore not tiltable up and down.
In addition, about a common site | part, the description of the subscript of "a, b, c" is abbreviate | omitted in the name and the description is omitted. Further, since the support arm 20 is symmetric in plan view, one of the support arms 20 will be described and the same reference numerals are given.

The support arm 20 is a box composed of a parallel portion 26, a vertical portion 27, and an extending portion 29. The parallel portion 26 is parallel to the excavation direction, the vertical portion 27 is formed so as to continuously extend in the width direction from the front end portion of the parallel portion 26, and the extending portion 29 has both ends of the vertical portion 27. The extension portions 29 are formed at each end of the vertical portion 27 to form a pair. An input shaft 25 is provided at the rear end of the parallel portion 26, a center output shaft 22, 23 is extended over the extended portions 29, 29, and a side output shaft 21, at both outer sides of the extended portions 29, 29, respectively. 21 protrudes in a watertight manner through sealing means (not shown). Both shafts 21 and 25 are arranged in the width direction.

(Drum cutter)
The drum cutter 30 includes a lower drum cutter 30a installed on the lower support arm 20a (generically referred to as lower center small drum cutters 32a and 33a and lower side large drum cutters 31a and 31a), and a middle drum installed on the middle support arm 20b. Cutter 30b (collectively referring to middle center small drum cutters 32b, 33b and middle side large drum cutters 31b, 31b), and upper drum cutter 30c (upper center small drum cutters 32c, 33c and upper side) installed on upper support arm 20c Large drum cutters 31c and 31c). In the following description, with respect to common parts, descriptions of subscripts “lower, middle, upper” and “a, b, c” are omitted.

Cutter bits 5 (indicated by “5 (31), 5 (31)” in the figure) are installed on the outer peripheral surfaces of the side large drum cutters 31, 31, and the cutters are disposed on the outer peripheral surfaces of the center small drum cutters 32, 33. Bit 5 (indicated by “5 (32), 5 (33)” in the figure) is provided. Further, the end portion of the vertical portion 27 of the support arm 20 and the extending portions 29 and 29 extending from the end portion are accommodated in the large side drum cutters 31 and 31. The large side drum cutters 31 and 31 are fixed to the side output shafts 21 and 21, respectively, and the small center drum cutters 32 and 33 are fixed to the center output shafts 22 and 23, respectively.
Both shafts 22 and 23 are arranged in the width direction. The lower side large drum cutters 31a, 31a installed on the lower support arm 20a are provided with an expansion / contraction mechanism for changing the excavation width (distance in the width direction of the excavated ground), and the other side large drum cutters 31, This is different from 31 but will be described in detail separately.

(Rotating mechanism)
The rotation mechanism 40 includes a pair of drive motors 41 and 41 that are installed in the main body 10 and generate a rotation force, and a rotation force transmission mechanism that transmits the rotation force to the drum cutter 30. Although the rotational force drive mechanism depends on the definition, the bevel gears 42 and 42 installed on the rotation shafts of the drive motors 41 and 41, the bevel gears 43 and 43 meshed with the bevel gears 42 and 42, and the support arm 20 in parallel. The gear train 46 formed in the section 26, the input shaft 25 to which the bevel gears 43 and 43 are fixed, the intermediate shaft 47 installed in the vertical section 27, the distribution mechanism 49 installed in the extending sections 29 and 29, the side An output shaft 21 and center output shafts 22 and 23 are included.
The rotational force generated by the drive motors 41, 41 is converted into rotational force about the width direction by the bevel gears 42, 42 and the bevel gears 43, 43 with the digging direction as its rotational axis and transmitted to the input shaft 25. The rotational force of the input shaft 25 is transmitted to the intermediate shaft 47 via the gear train 46. Since the shaft end portions of the intermediate shaft 47 reach the extending portions 29 and 29, respectively, the rotational force transmitted to the intermediate shaft 47 is transmitted to the distribution mechanisms 49 and 49, and the side output shafts 21 and 21 and the center output are transmitted. This is distributed to the rotational force of the shafts 22 and 23. Thus, the rotational force generated by the drive motors 41, 41 is transmitted to the drum cutter 30.

(Tilting means)
The tilting means 50 is installed only on the lower support arm 20a. That is, the tilting means 50 includes a tilting jack 51 provided with a tilting piston 52 and a bracket 53 installed on the lower support arm 20 a and connected to the tilting piston 52. The lower support arm 20a is tiltably installed on the bulkhead 12 on the input shaft 25a. The input shaft 25a is rotatably supported by a bearing 24a installed on the lower support arm 20a and a bearing 44a installed on the bulkhead 12. Has been. Therefore, the lower support arm 20a is tilted in the vertical direction by the advancement and retreat of the tilting piston 52, and stands or falls (the state where the lower support arm 20a is fallen is indicated by a one-dot chain line).
The input shaft 25 is formed of a coaxial inner shaft and an outer shaft (same as the outer tube), the bevel gears 43 and 43 are fixed to the inner shaft, and meshed with the gear train 46 to transmit rotational force. On the other hand, the outer shaft may be supported by the bearing 24a and the bearing 44a to transmit excavation force. Further, instead of the bracket 53, a pinion may be installed on the outer shaft, and the rack engaged with the pinion may be moved by the tilting jack 51.

(Ground improvement agent feeding means)
The ground improver feeding means 60 includes an injection pipe 61 installed on the bottom surface 19 of the main body 10, a stock tank for storing a ground improver (not shown), a pressurizing means for pressurizing a ground improver (not shown), and the like. Have. Therefore, the ground improvement agent can be fed into the excavated ground from the position of the bottom surface 19.
In addition, a ground improvement agent is suitably selected according to the characteristic before improving a ground, and the characteristic requested | required after improvement. Further, the installation position and the feeding direction of the injection pipe 61 are not limited to those shown in the figure, but are installed on the bulkhead 12 so that the lower drum cutter 30a is exactly excavated by the lower drum cutter 30a. The ground improvement agent may be pressed or injected into the excavation ground toward the existing ground, or the advancing / retreating means is installed in the injection pipe 61 so that the ground improvement agent is placed in the excavation ground at a position close to the lower drum cutter 30a. You may make it send. Moreover, although related also to Embodiment 3 described later, the injection pipe 61 may be installed at a position where agitation and mixing of the excavated ground and the ground improvement agent occurs. If needed, if the ground improvement agent is delivered to the excavation ground, the desired position of ground improvement can be achieved. The type or the like may be arbitrarily selected or changed.

(Expansion / reduction mechanism of the lower side large drum cutter)
4 and 5 are diagrams for explaining the expansion / contraction mechanism of the lower side large drum cutter in the shield machine according to Embodiment 1 of the present invention. FIG. 4 (a) is a plan view, and FIG. ) Is an enlarged sectional view, and FIG. 5 is a sectional view in plan view. In FIG. 4, the lower side large drum cutter 31a changes the distance in the rotational axis direction (same in the width direction) between the center-side drum 311, the side-side drum 314, and the center-side drum 311 and the side-side drum 314 by hydraulic pressure. And a possible expansion / contraction jack 315.

  In FIG. 5, the hydraulic pressure to the expansion / contraction jack 315 is formed from a hydraulic unit (not shown) installed in the main body 10 to the hydraulic hose 321, the rotary joint 322 installed at the end of the input shaft 25, and the input shaft 25. An oil supply hole (not shown), a rotary joint 323 installed near the center of the input shaft 25, a hydraulic hose 324 accommodated in the support arm 20 (the same in the parallel portion 26 and the vertical portion 27), and the side output shaft 21a The rotary joint 325 installed at the center side end, the oil supply hole (not shown) formed in the side output shaft 21a, the rotary joint 326 installed at the side side end of the side output shaft 21a, and the side shift drum 314 are stored. Are transmitted via respective hydraulic hoses 327. The hydraulic hoses 321, 324, and 327, and an oil supply hole (not shown) each have a pressurization (for oil supply) and a decompression (for return) use.

4 and 5 again, the center-side drum 311 is divided into a center-side portion and a side-side portion by a mounting wall 312 that is installed at the approximate center in the width direction.
An extension portion 29 a of the support arm 20 a is accommodated inside the portion near the center, and the mounting wall 312 is fixed to the side output shaft 21. Also, a side drum 312 is disposed inside the side portion. The side shift drum 312 is attached to the side output shaft 21 by, for example, a spline or the like so that the circumferential direction is constrained and slidable in a direction parallel to the side output shaft 21 (the same in the width direction). Therefore, by extending / contracting the expansion / contraction jack 315, the excavation width of the lower side large drum cutter 31a varies, and the center side drum 311 and the side side drum 314 rotate integrally.

  A plurality of notches 313 are provided at the side edge of the center-side drum 311, and the cutter bit 5 is installed on the outer peripheral surface excluding the notches 313 (indicated by 5 (311) in the figure). . On the other hand, a cutter bit 5 is installed on the outer peripheral surface of the side-side drum 314 at a position that matches the phase of the notch 313 of the center-side drum 311 (indicated by 5 (314) in the figure). Therefore, when the expansion / contraction jack 315 is contracted, the cutter bit 5 (314) installed on the side-side drum 314 enters the notch 313 of the center-side drum 311 and when the expansion / contraction jack 315 is extended, the cutter bit 5 (314) is arranged in a phase different from that of the cutter bit 5 (311) installed on the center-side drum 311.

(Drilling procedure-When not excavating the lower part of the main unit)
When using the shield machine 1 configured as described above to dig without forming a digging portion at the lower part of the main body 10, the tilting piston 52 of the tilting jack 51 is contracted to erect the lower support arm 20a. In addition to leveling, the expansion / contraction jack 315 is extended to widen the excavation width of the lower side large drum cutters 31a, 31a, and all the drum cutters 30 are rotated to perform excavation. As a result, a range that is substantially the same as the projected area of the main body 10 projected in the digging direction (the same as the rectangular range surrounded by the position A, the position B, the position C, and the position D in FIG. 3) can be excavated. At this time, since there is almost no excavation residue between the center small drum cutter 32 and the center small drum cutter 33 and between the center small drum cutters 32 and 33 and the side large drum cutters 31 and 31, Excavation earth and sand do not collide directly, and increase in excavation resistance is prevented.

(Drilling procedure-When excavating the lower part of the main unit)
When the shield machine 1 having the above configuration is used to dig while forming a digging part at the lower part of the main body part 10, the tilting piston 52 of the tilting jack 51 is extended and the lower support arm 20a is laid down so as to be substantially vertical. In addition to tilting downward, the expansion / contraction jack 315 is contracted to set the width of the lower side large drum cutters 31a, 31a to be narrowed, and all the drum cutters 30 are rotated for excavation. Thereby, the entire range of the projected area projected from the main body 10 in the excavation direction (the same as the rectangular range surrounded by the position A, the position B, the position C, and the position D) is excavated, and further, the lower side By the large drum cutters 31a and 31a and the lower center small drum cutter 32a, the lower part of the main body 10 is narrower than the width of the main body 10 (a rectangular shape surrounded by the positions E, F, G and H). The same in range) can be excavated.

  At this time, since the expansion and contraction of the tilting piston 52 of the tilting jack 51 can be controlled as appropriate, it becomes possible to form a groove-shaped excavation ground at a desired position continuously or intermittently along the excavation direction. The ground improvement can be performed on the excavated ground formed at a desired position. Further, in the lower part of the main body 10, an unexcavated region along both edges (the ground other than the excavated ground, that is, the ground in the unexcavated range, more specifically, the range between the position D and the position E and the position H and the position A Therefore, the main body portion 10 is supported in the remaining excavation area stronger than the excavated ground, and the excavation direction does not become unstable.

Further, since the forward speed of the shield machine 1 is low, the range of the main body 10 can be reduced by repeating the standing up and lying down of the lower support arm 20a (expansion and reduction of the excavation width by the lower side large drum cutters 31a and 31a). There is no excavation residue in the rectangular range surrounded by the position A, the position B, the position C, and the position D in FIG. 3B.
In addition, although the above has illustrated what the support arm 20 was installed over three steps, a lower stage, a middle stage, and an upper stage, this invention is not limited to this, The lower stage support arm 20a is extended to the full range of an up-down direction. One or both of the middle support arm 20b and the upper support arm 20c may be removed by being tiltable so as to cover, or a support arm may be further added on the upper support arm 20c.

[Embodiment 2]
(Shield machine)
6 to 8 show the front part of the shield machine according to the second embodiment of the present invention. FIG. 6 is a sectional view in side view, FIG. 7 is a sectional view in plan view, and FIG. FIG. In addition, the same code | symbol is attached | subjected to this same part as Embodiment 1 (FIGS. 1-3), and one part description is abbreviate | omitted. In addition, according to the first embodiment, the description of the subscripts “lower, middle, upper” and “a, b, c” is omitted for common parts, and one of the parts arranged symmetrically is omitted. explain.

  6-8, the shield machine 2 is the main body part 10, the support arm 70 which protrudes ahead of the main body part 10 (left side in FIG. 6), and the support arm 70, and rotation orthogonal to the digging direction. Excavation means (hereinafter referred to as “drum cutter”) 80 having a shaft, a rotation mechanism 40 that is installed in the main body 10, generates a rotational force and transmits the rotational force to the drum cutter 80, and And ground improvement agent feeding means 60 for feeding the ground improvement agent to the lower part.

(Support arm)
The support arm 70 includes a lower support arm 70a, an intermediate support arm 70b, and an upper support arm 70c that are fixed to the bulkhead 12 so as not to tilt. The support arm 70 includes a pair of parallel portions 76 and 76 parallel to the excavation direction, and a pair of extending portions 79 and 79 extending forward along the inner surface of the parallel portions 76 and 76. Is the body. At this time, the surface which extended the inner surface of the parallel parts 76 and 76 and the outer surface of the extension parts 79 and 79 are parallel, and are adjoining.
An input shaft 75 is installed at the rear end of the pair of parallel portions 76, 76, and a center output shaft 73 is installed in a watertight manner through unillustrated sealing means over the extended portions 79, 79. ing. On the other hand, with respect to the outside of the extending portions 79, 79, side output shafts 71a, 71a are provided on the lower support arms 70a, 70a, and side output shafts 71b, 71b and side output shafts 72b, 72b are provided on the middle support arms 70b, 70b. However, the side support shafts 71c and 71c and the side output shafts 72c and 72c protrude from the upper support arms 70c and 70c in a watertight manner through sealing means (not shown). That is, the lower support arms 70a and 70a are different from the other support arms 70 in that the side output shaft is one on each side.

(Drum cutter)
The drum cutter 80 includes a lower drum cutter 80a installed on the lower support arm 70a (referred to collectively as lower side small drum cutters 81a and 81a and a lower center large drum cutter 83a), and a middle drum cutter 80b installed on the middle support arm 70b. (Collectively referring to the middle side small drum cutters 81b, 81b, 82b, 82b and the middle center large drum cutter 83b), and the upper drum cutter 80c (upper side small drum cutters 81c, 81c, 82c, 82c and upper center large drum cutter 83c).
That is, the lower drum cutter 80a includes a pair of side small drum cutters (81a, 81a), while the middle drum cutter 80b has two pairs (81b, 81b; 82b, 82b), and the upper drum cutter 80c has two pairs. (81c, 81c; 82c, 82c).

  Cutter bits 5 (indicated by “5 (81), 5 (81), 5 (82), 5 (82)” in the figure) are installed on the outer peripheral surfaces of the side small drum cutters 81, 81, 82, 82. A cutter bit 5 (indicated by “5 (83)” in the figure) is provided on the outer peripheral surface of the center large drum cutter 83. Further, the extending portions 79 and 79 of the support arm 70 are accommodated in the center large drum cutter 83. The side small drum cutters 81 and 81 are fixed to the side output shafts 71 and 71, the side small drum cutters 82 and 82 are fixed to the side output shafts 72 and 72, and the center large drum cutter 83 is fixed to the center output shaft 73, respectively. Yes.

(Rotating mechanism)
The rotation mechanism 40 includes a pair of drive motors 41 and 41 that are installed in the main body 10 and generate a rotation force, and a rotation force transmission mechanism that transmits the rotation force to the drum cutter 80. Although the rotational force transmission mechanism depends on the definition, the bevel gears 42 and 42 installed on the rotation shafts of the drive motors 41 and 41, the bevel gears 43 and 43 meshed with the bevel gears 42 and 42, and the support arm 70 are parallel to each other. A gear train 46 formed in the portions 76, 76, an input shaft 75 to which the bevel gears 43, 43 are fixed, an intermediate shaft 47 installed so as to straddle the parallel portions 76, 76 and the extending portions 79, 79, The extending portion 79 includes a distribution mechanism 49, side output shafts 71, 71, 72, 72 and a center output shaft 73.
The rotational force generated by the drive motors 41 and 41 is converted into rotational force about the width direction by the bevel gears 42 and 42 and the bevel gears 43 and 43 with the digging direction as the rotational axis, and transmitted to the input shaft 75. The rotational force of the input shaft 75 is transmitted to the intermediate shaft 47 via the gear trains 46 and 46. The rotational force transmitted to the intermediate shafts 47, 47 is transmitted to the distribution mechanisms 49, 49 and distributed to the rotational forces of the side output shafts 71, 71, 72, 72 and the center output shaft 73. Thus, the rotational force generated by the drive motors 41 and 41 is transmitted to the drum cutter 80.

(Ground improvement agent feeding means)
The ground improvement agent feeding means 60 stores an injection pipe 61 movably installed on the bottom surface 19 of the main body 10, an advance / retreat mechanism (not shown), a pressure mechanism for pressurizing the ground improvement agent, and further stores the ground improvement agent. Has stock tanks. Therefore, the injection pipe 61 can be made to enter the excavated ground and the ground improver can be fed there. In addition, since the injection pipe 61 can be brought close to the lower center large drum cutter 83a, the excavated ground and the ground improving agent fed to the ground can be easily agitated and mixed, thereby enabling more uniform and effective ground improvement. Become.
In addition, a ground improvement agent is suitably selected according to the characteristic before improving a ground, and the characteristic requested | required after improvement. Further, the installation position of the injection pipe 61 and the feeding direction are not limited to those shown in the figure, and may be installed on the bulkhead 12. Also, if the purpose of ground improvement at the lower part of the main body can be achieved without hindering excavation, the advance / retreat mechanism (not shown) may be removed so that it always protrudes by a predetermined length. In addition, the installation position of the injection pipe 61, the manner of feeding such as injection, injection, etc., the type of ground improvement agent, and the like may be arbitrarily selected or changed.

(Guidelines)
Using the shield machine 2 having the above-described configuration, the lower side small drum cutters 81a and 81a installed in the lower drum cutter 80a are substantially at the same position as the bottom surface 19 of the main body 10 (the positions D and E in FIG. 8). And the same as the line connecting the position H and the position A), and the rectangular range surrounded by the positions I, J, F and G is excavated by the lower center large drum cutter 83a. Thereby, the excavation ground (corresponding to the rectangular range surrounded by the position E, the position F, the position G, and the position H) having a predetermined depth can be formed in the lower part of the central region of the main body 10.
Therefore, if all the drum cutters 80 are rotated, substantially the entire projected area of the main body part 10 projected in the digging direction is excavated, and the lower center large drum cutter 83a causes the lower part of the main body part 10 to be Drilling can be continuously performed only in a range narrower than the width (same as the width of the lower center large drum cutter 83a).

At this time, it is possible to continuously form the desired improved ground in the process of shield excavation and improve the lower ground of the segment by sending the ground improver to the excavated ground by the ground improver feeding means 60 become. Further, in the lower part of the main body 10, there remains an unexcavated area (the ground of the unexcavated range, more specifically, the range of the position D and the position E and the ground of the range of the position H and the position A along the both edges). ) Is formed, the main body portion 10 is supported in the remaining excavation area stronger than the excavated ground, and the excavation direction does not become unstable.
Further, there is almost no excavation residue between the side small drum cutters 81, 81 and the side small drum cutters 82, 82, and between the side small drum cutters 81, 81, 82, 82 and the center large drum cutter 83. For this reason, since unexcavated earth and sand do not collide directly with the support arm 70 or the bulkhead 12, an increase in excavation resistance is prevented. Further, as compared with the first embodiment, the structure is simplified because the tilting means of the lower support arm and the expansion / contraction mechanism of the lower drum cutter are not provided.

[Embodiment 3]
9 to 11 show a front part of a shield machine according to Embodiment 3 of the present invention, in which FIG. 9 is a sectional view in side view, FIG. 10 is a sectional view in plan view, and FIG. 11 is a front view. FIG. The shield machine 2 according to the third embodiment includes a main body 10, a support arm 70 that projects forward (left side in FIG. 9) of the main body 10, and a rotation axis that is supported by the support arm 70 and that is orthogonal to the excavation direction. A drum cutter 80, a rotating mechanism 40 which is installed in the main body 10 and generates a rotational force and transmits the rotational force to the drum cutter 80; and a ground which injects or injects a ground improver into the lower portion of the main body 10 And an improver feeding means 60.

  Since the shield machine according to the third embodiment of the present invention has almost the same configuration as that according to the second embodiment, the same effect can be obtained due to the configuration. Therefore, the description about the common part is omitted. However, the installation position of the injection pipe 61 of the ground improvement agent feeding means 60 and, therefore, the method of feeding the ground improvement agent are different from those in the second embodiment. In other words, the injection tube 61 has a distal end installed in the vicinity of the lower drum cutter 80a. Due to the arrangement of the ground improvement agent feeding means 60, more precisely, the ground improvement agent feeding position, the ground improvement agent is not simply injected or injected into the ground excavated by the lower drum cutter 80a. Mixing and stirring with can also be performed. The degree of mixing and agitation varies depending on the excavation procedure, particularly the operation of the lower drum cutter 80a, but the desired effect can be obtained while digging the shield in the same manner as in the case of mere injection or injection of the ground improvement agent or with a better effect. The improved ground can be continuously formed, and the ground below the segment can be improved.

[Embodiment 4]
(Shield machine)
12 and 13 show a front part of a shield machine according to Embodiment 4 of the present invention, in which FIG. 12 is a sectional view in side view, and FIG. 13 is a front view. In addition, the same code | symbol is attached | subjected to this same part as Embodiment 2 (FIGS. 6-8), and one part description is abbreviate | omitted. In addition, in the same manner as in the first embodiment, the description of the “lower, middle, upper” and “a, b, c” subscripts for common parts is omitted, and one of the symmetrically arranged parts is Will be described.

  12 and 13, the shield machine 3 includes a main body 10, a support arm 70 that protrudes in front of the main body 10 (left side in FIG. 12), and a support arm 70 that rotates perpendicular to the digging direction. Excavation means (hereinafter referred to as “drum cutter”) 80 having a shaft, a rotation mechanism 40 that is installed in the main body 10, generates a rotational force and transmits the rotational force to the drum cutter 80, and And an improved soil filling means 90 for sending out rearward.

(Drum cutter)
The drum cutter 80 in the shield machine 3 includes a lower drum cutter 80a, an intermediate drum cutter 80b, and an upper drum cutter 80c. The lower, middle and upper drum cutters have the same structure, and are composed of side small drum cutters 81 and 81 and side small drum cutters 82 and 82 installed on both sides and a center large drum cutter 83 installed in the center. There are a total of 5 drum cutters.

(Improved soil filling means)
The improved soil filling means 90 includes an outer mold 91, a frame frame 92, a press-fitting cylinder 94, and an improved soil supply means (not shown). The outer mold 91 has a rectangular cross section, and is watertightly installed on the inner surface side of the tail plate 17 having the same rectangular cross section.
A plurality of shield jacks 16 are installed in front of the outer mold 91 so as to be arranged in a rectangular shape while maintaining a certain distance along the inner surface of the tail plate 17. On the lower side in the vertical direction of the main body 10, the shield jack 16 is arranged at a predetermined interval in the vertical direction from the inner surface of the tail plate 17 (vertically above the inner surface by a predetermined distance). Further, the press-fit cylinder 94 is arranged in a state where physical interference with the shield jack 16 is avoided.

  Due to the plurality of shield jacks 16 arranged as described above, a segment having a cross section smaller than that of the main body 10, for example, a cylindrical segment having a height lower than that of the main body 10, and a top surface (a surface substantially vertically above) ) Takes a reaction force on the main body portion 10 and substantially coincides with that of the main body portion 10 to propel the main body portion 10 forward. Then, with the shield excavation, the segment cylindrical body 6 having a rectangular cross section is formed shorter in the vertical direction than the main body portion 10, and the bottom surface of the segment cylindrical body 6 (position S (back) and position V (front) in FIG. 12). ); Corresponding to a vertical lower outer wall surface) and a lower portion of the outer mold 91 (corresponding to a vertical lower mold surface), a gap of a predetermined distance is formed. become. The end frame plate 92 is disposed in the gap, the press-fit piston 93 of the press-in cylinder 94 is connected to the end frame plate 92, and an unillustrated improved soil supply is supplied to a through hole (not shown) provided in the end frame plate 92. An improved soil supply pipe is installed.

(Guidelines)
Using the shield machine 3 having the above-described configuration, all the drum cutters 80 are used to form a rectangular range having substantially the same shape as the main body 10 (a range surrounded by the positions A, B, C, and D in FIG. 13). Excavate the same). Then, when a shield is excavated by taking a reaction force on the segment tubular body 6 toward the rear in the excavation range, the wife frame plate is formed in the gap between the lower surface of the segment tubular body 6 and the lower portion of the outer mold frame 91. The improved soil 7 is supplied toward the rear side of 92, and further, the press-fit piston 93 is extended to push the end frame plate 92 backward to feed or press-fit the supplied improved soil 7 to a predetermined position. The gap is filled with the improved soil 7. By continuously repeating this press-fitting or filling operation, the improved soil 7 is disposed at the lower part of the segment cylindrical body 6, so that an improved ground is formed at the lower part of the segment cylindrical body 6 within the gap. It will be.
Since this ground improvement is performed without excavating the lower part of the main body part 10, the main body part 10 is stably supported by the unexcavated ground, and the excavation direction does not become unstable.

  In the position or range where it is not necessary to improve the lower portion of the segment cylindrical body 6 during the shield excavation process, the wife frame plate 92 is formed in the gap between the lower surface of the segment cylindrical body 6 and the lower portion of the outer mold 91. The excavated soil (unmodified soil) is supplied to the rear of the pipe, and the press-in piston 93 is extended to push the end frame plate 92 backward to feed or press-fit the supplied excavated soil to a predetermined position. The gap in the position is filled with the excavated soil. In this sense, improved soil supply means (not shown) can supply excavated soil, and can selectively supply the improved soil 7 and excavated soil (supplied soil switching means (not shown)). Provided).

  A waterproof sheet 95 is installed at the front end of the outer mold 91, and when the press-fit piston 93 is contracted, the end frame 92 comes into watertight contact with the waterproof sheet 95, so that the supplied improved soil 7, groundwater, etc. Does not enter the main body 10. Further, since the tail seal 18 slides in a watertight manner on the lower surface of the compressed improved soil 7, the watertightness of the main body 10 is maintained.

[Embodiment 5]
(Shield digging method)
FIG. 14 is a flowchart illustrating a shield excavation method according to Embodiment 5 of the present invention. For convenience of explanation, the case where the shield machine 1 of the first embodiment is used will be described as an example. The shield excavation method has steps 1 to 10 described later.

  Step 1: Excavate the front part of the main body 10 formed in a cylindrical shape in a range having substantially the same cross section as the main body 10. That is, a range surrounded by A-B-C-D by the lower drum cutter 30a, the middle drum cutter 30b, and the upper drum cutter 30c (hereinafter may be collectively referred to as “drum cutter 30”) (see FIG. 3). , The reaction force is applied to the segment cylindrical body 6 at the rear, and the main body portion 10 is moved forward (indicated by “digging in normal section excavation”, “S1”).

  Step 2: Continue the excavation in the normal section excavation, and stop moving forward when the point where the lower ground is scheduled to be improved is reached. That is, no reaction force is received from the segment tubular body 6 (indicated by “arrival at lower ground improvement point”, “S2”).

  Step 3: Therefore, the width of the lower drum cutter 30a is narrowed. That is, the expansion / contraction jack 315 is moved backward to bring the side drum 314 closer to the center. At this time, the drum cutter 30 may continue to rotate or may stop (indicated by “lower drum horizontal width reduction”, “S3”).

  Step 4: Next, the lower drum cutter 30a whose width is narrowed is tilted downward while rotating. Then, the E-H width (same as the FG width, see FIG. 3) is excavated in the front portion of the main body 10 ("lower drum down, lower excavation", indicated by "S4") To do).

  Step 5: Eventually, when a predetermined depth, that is, a range surrounded by E-F-G-H (see FIG. 3) has been excavated, the lower drum cutter 30a is lifted upward, and a normal cross-section excavation is performed. That is, the width at step 1 is restored. (Displayed as “Up the lower drum and return to the original position”, “S5”).

Step 6: Then, a normal cross section (the same as the range surrounded by A-B-C-D) is excavated with the drum cutter 30, and the reaction force is applied to the segment cylindrical body about the radius of the large drum cutter 31, The main body 10 is moved forward (displayed as “digging about half the diameter of the excavating drum in a normal section”, “S6”).
Step 7: Steps 3 to 6 are repeated until the main body 10 moves forward by a predetermined distance (displayed in “required amount excavation” and “S7”).

  Step 8: After determining that the required amount of the lower part of the main body 10 has been excavated, that is, after the excavated ground reaches the position of the injection pipe 61 of the ground improver feeding means 60, the lower ground is removed. In order to improve, the ground improvement agent is fed into the excavated ground ("improving agent is fed into the existing excavation part, ground improvement", indicated by "S8").

  Step 9: Then, Steps 3 to 8 are repeated until the ground improving agent is sent to the lower part of the main body 10 over a predetermined distance (displayed in “lower part completion”, “S9”).

  Step 10: After passing through the point where the improvement of the lower ground is planned, the process returns to the excavation by the normal section excavation (displayed by “digging by the normal section excavation” and “S10”).

Therefore, in the shield excavation process, the excavation ground and the improved ground are formed at the lower portion of the main body 10 and the segment cylindrical body 6 of the shield excavator 1, and at an arbitrary position and distance below the segment. Since the ground improvement agent is fed into the ground excavated in advance, the penetration of the ground improvement agent is promoted and the improved ground is uniformly formed. After the excavation pit is formed, it is no longer necessary to perform ground improvement such as driving piles, retaining earth, and stopping water from the inside of the pit, and the existing segments required to perform such work are destroyed, removed, etc. It is no longer necessary to install pressurizing means and other equipment / equipment for infiltrating the improver. Even if it is necessary to improve the ground after the excavation mine is formed, excavating the ground in advance facilitates subsequent ground improvement work, and if the improved ground is formed in advance, Generation | occurrence | production of the danger and disorder | damage | failure at the time of destruction, removal, etc. (for example, the situation where earth and sand or groundwater erupts toward the inside of a mine by exposing a natural ground in a mine) is prevented or suppressed.
Moreover, since the width | variety (EH width) which excavates the lower part of the main-body part 10 of the shield machine 1 is narrower than the width | variety (AD width) of the main-body part, the main-body part 10 is supported by the unexcavated ground. Therefore, the posture of the main body 10 is stable and the excavation direction does not fluctuate. Moreover, the formed segment cylindrical body 6 is stably supported by both the improved ground and the unexcavated ground.
In addition, although the above demonstrated the case where the shield machine 1 was used for Embodiment 1, this invention is not limited to this, It is an excavator which can perform the said steps 1-10. If there is, the embodiment, model and the like are not limited.

[Embodiment 6]
(Shield digging method)
FIG. 15 is a flowchart for explaining a shield excavation method according to Embodiment 6 of the present invention. For convenience of explanation, the case where the shield machine 3 of Embodiment 4 is used will be described as an example. The shield excavation method has steps 11 to 19 (shown as “S11 to S19” in FIG. 15).

Step 11: Excavate the front part of the main body 10 formed in a cylindrical shape in a range having substantially the same cross section as the main body 10. That is, a rectangular range surrounded by A-B-C-D by the lower drum cutter 80a, the middle drum cutter 80b, and the upper drum cutter 80c (hereinafter sometimes collectively referred to as “drum cutter 80”) (see FIG. 13). ), The reaction force is applied to the segment cylindrical body 6 at the rear, and the main body 10 is advanced.
At this time, the segment cylindrical body 6 is a rectangle surrounded by STV (see FIG. 12; in FIG. 12, the position T is the back and the position U is the front), and the top surface of the tail plate 17 ( Because it is arranged close to the top surface of the main body 10, a gap is formed between the lower surface (the surface connecting S and V) of the segment cylindrical body 6 and the lower part of the outer mold 91. Therefore, at the same time, excavated soil (unmodified soil) is supplied into the gap to be press-fitted or filled. That is, by extending the press-fit piston 93 and pushing out the end frame 92, the excavated soil is fed into the gap, where it is compressed and filled. The improved soil supply means installed in the main body 10 includes supply soil switching means for selectively supplying either the improved soil 7 or the excavated soil toward the rear of the end frame 92.

  Step 12: Excavate by one ring of the segment, and when the main body portion 10 has advanced by one ring, assemble the segment cylindrical body 6 and repeat Step 11 and Step 12 until the lower ground improvement start point is reached. .

  Step 13: When the lower ground improvement start point is reached, the excavated soil press-in / fill mode is switched to the improved soil press-in / fill mode. That is, the supply soil switching means is operated to switch the supply object from the excavated soil to the improved soil 7, and the improved soil 7 can be supplied to the rear of the frame frame 92 by the improved soil supply means.

  Step 14: The front part of the main body 10 is excavated in the same manner as in Step 11, the reaction force is applied to the segment cylindrical body 6 at the rear, and the main body 10 is advanced. At the same time, the improved soil 7 is supplied into the gap formed between the bottom surface of the segment cylindrical body 6 and the lower part of the outer mold 91 to be press-fitted or filled. That is, the improved soil 7 is compressed by extending the press-fit piston 93 and pushing out the end frame 92 and press-fitted to a predetermined position, and the clearance at that position is filled with the improved soil 7.

  Step 15: Excavate by one ring of the segment, and when the main body portion 10 has advanced by one ring, assemble the segment cylindrical body 6 and repeat Steps 14 and 15 until reaching the lower ground improvement end point. .

  Step 16: When the lower ground improvement end point is reached, the improved soil press-in / fill mode is switched to the excavated soil press-in / fill mode. In other words, the supply soil switching means is operated to switch the supply target from the improved soil 7 to the excavated soil, and the improved soil supply means allows the excavated soil to be supplied toward the rear of the frame frame 92.

Step 17: As in step 11, shield excavation and excavation soil filling are performed.
Step 18: As in step 12, the segment cylindrical body 6 is assembled, and step 17 and step 18 are repeated until the excavation is completed.

  Step 19: Steps 11 to 18 are repeated until excavation of a predetermined section is completed. That is, when there are one or more ground improvement sections in a predetermined excavation section, the improvement soil 7 is in the gap between the lower surface of the segment tubular body 6 and the lower part of the outer mold 91 in the ground improvement section. In the range excluding the ground improvement section, the excavated soil is sent in place of the improved soil 7 and is pressed and filled.

Therefore, an improved ground is formed at the lower part of the segment cylindrical body 6 in the shield excavation process, and at an arbitrary position and distance below the segment. For example, in a specific area where soft ground exists, the lower part of the segment can be filled with improved soil, and in other areas, excavated soil can be filled. Further, since the lower part of the segment is filled with the improved soil or excavated soil, the main body 10 is stably supported by the ground in the entire excavation section, and the excavation direction does not become unstable.
It should be noted that the excavated soil is treated soil that has been subjected to a predetermined treatment (excluding those that have undergone a special improvement treatment such as strength improvement) even if it has just been excavated by the drum cutter 80. May be.
In addition, if the ground at the bottom of the segment is improved in advance, it is not necessary to perform ground improvement such as pile placement, earth retaining, water stoppage, etc. from the inside of the pit after forming the excavation mine. The improvement of the ground facilitates the subsequent ground improvement work and prevents or suppresses the occurrence of dangers and failures associated with the work.

  As described above, according to the present invention, it is possible to improve the ground at the bottom of the segment while shield digging, maintaining the posture of the main body of the shield digging machine properly, stabilizing the digging direction, As a result, the excavation mine is stabilized, and further, the work load related to ground improvement after formation of the excavation mine is reduced (in some cases, the subsequent work is unnecessary). It is possible to realize a shield excavation method and a shield excavator that can suppress the occurrence of an obstacle as much as possible.

Sectional drawing of the side view which shows the front part of the shield machine which concerns on Embodiment 1 of this invention. Sectional drawing of the planar view which shows the front part of the shield machine which concerns on Embodiment 1 of this invention. The front view which shows the front part of the shield machine which concerns on Embodiment 1 of this invention. The perspective view which shows typically the lower stage large drum cutter in a shield machine. Sectional drawing of the expansion / contraction mechanism of the lower stage large drum cutter in a shield machine. Sectional drawing of the side view which shows the front part of the shield machine which concerns on Embodiment 2 of this invention. Sectional drawing of the planar view which shows the front part of the shield machine which concerns on Embodiment 2 of this invention. The front view which shows the front part of the shield machine which concerns on Embodiment 2 of this invention. Sectional drawing of the side view which shows the front part of the shield machine which concerns on Embodiment 3 of this invention. Sectional drawing of the planar view which shows the front part of the shield machine which concerns on Embodiment 3 of this invention. The front view which shows the front part of the shield machine which concerns on Embodiment 3 of this invention. Sectional drawing of the side view which shows the front part of the shield machine which concerns on Embodiment 4 of this invention. The front view which shows the front part of the shield machine which concerns on Embodiment 4 of this invention. The flowchart explaining the shield digging method which concerns on Embodiment 5 of this invention. The flowchart explaining the shield excavation method which concerns on Embodiment 6 of this invention.

Explanation of symbols

1 Shield machine 2 Shield machine 3 Shield machine 5 Cutter bit 6 Segment cylindrical body 7 Improved soil
DESCRIPTION OF SYMBOLS 10 Main-body part 11 Skin plate 12 Bulk head 13 Recessed part 14 Excavation part 15 Screw conveyor 16 Shield jack 17 Tail plate 18 Tail seal 19 Bottom face 20 Support arm 21 Side output shaft 22 Center output shaft 23 Center output shaft 24 Bearing 25 Input Shaft 26 Parallel portion 27 Vertical portion 29 Extension portion 30 Drum cutter 31 Side large drum cutter 32 Center small drum cutter 33 Center small drum cutter 40 Rotating mechanism 41 Drive motor 42 Bevel gear 43 Bevel gear 44 Bearing 46 Gear train 47 Intermediate shaft 49 Distributing mechanism 50 Tilt means 51 Tilt jack 52 Tilt piston 53 Bracket 60 Ground improver feeding means 61 Injection pipe 70 Support arm 71 Side output shaft 72 Side output shaft 73 Center output shaft 75 Input shaft 76 Parallel Part 79 Extension part 80 Drum cutter 81 Side small drum cutter 82 Side small drum cutter 83 Center large drum cutter 90 Improved soil filling means 91 Outer mold frame 92 Wife frame plate 93 Press-in piston 94 Press-in cylinder 95 Waterproof sheet 311 Center side drum 312 Mounting wall 313 Notch 314 Side drum 315 Expansion / reduction jack 321 Hydraulic hose 322 Rotary joint 323 Rotary joint 324 Hydraulic hose 325 Rotary joint 326 Rotary joint 327 Hydraulic hose

Claims (2)

Excavating the front surface of the cylindrical main body portion, taking a reaction force on the cylindrical segment disposed behind the main body portion, and in the process of shield digging to advance the main body portion forward, the lower part of the front surface of the main body portion is A shield excavation method characterized in that excavation ground is formed in the lower part of the main body part by excavation, and improved ground is formed in the lower part of the segment by feeding a ground improvement agent into the excavation ground,
The shield excavation method , wherein a width of excavating a lower portion of the front surface of the main body is narrower than a width of the front surface of the main body . A main body formed in a cylindrical shape;
  Excavation means for excavating the front surface of the main body,
  Extruding means that takes a reaction force on a cylindrical segment disposed behind the main body and advances the main body forward,
  A shield excavator having a soil discharging means for discharging the excavated earth and sand,
  The shield excavator is characterized in that the excavation means can freely form a trench excavation ground in the lower part of the main body,
  It has a ground improver feeding means for feeding a ground improver into the excavated ground of the groove, thereby forming the improved ground at the lower part of the segment in the process of moving the main body forward by the pushing means. Characteristic shield machine.

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