JP3182099B2 - Removal method of shield excavator from arrival port - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing a shield excavator that has reached a reaching shaft into a reaching shaft while preventing water from flowing out of the wellhead.

[0002]

2. Description of the Related Art Conventionally, in a shield method in which a tunnel is excavated underground by a shield excavator from a starting shaft to a reaching shaft and a segment is laid on an excavated wall surface, the shield excavator reaches the reaching shaft. Then, the shield excavator is temporarily removed into the arrival shaft, and the arrival tunnel is used as a starting shaft for the next tunnel excavation, and the next tunnel intersecting the length direction of the previously excavated tunnel is used. Drilling is starting to take place. On the other hand, when the construction of the tunnel is completed, the skin plate of the shield excavator is left buried in the excavated ground, and various members constituting the shield excavator are disassembled and removed.

[0003]

However, when the tunnel is being excavated by the shield excavator, the shield excavator is attached to the outer peripheral surface of the segment for covering the excavated tunnel wall surface at the rear end inner peripheral surface of the skin plate of the shield excavator. The tail seals are pressed against each other, so that the backing material and groundwater injected into the gap between the lining segment and the excavation wall can be prevented from flowing into the inside of the machine, but the shield excavator After reaching the shaft, if the shield excavator is removed as in the former method, the gap between the excavated wall and the lining segment reaches the open shaft, and the backing material and groundwater flow into the shaft. In the case of sandy gravel ground, the excavation wall may collapse, and therefore it is necessary to perform a water stoppage treatment on the wellhead, and the reinforcing chemical It had to be subjected to the implantation process.

On the other hand, according to the latter method, since the skin plate is left in the wellhead, it is possible to prevent the backing material and the like from flowing out as described above. It is necessary to disassemble and remove the various components that are being removed, and to perform the next tunnel excavation work, it is necessary to reassemble it in a new skin plate, which requires considerable time and labor. There is a problem that construction efficiency is reduced.

The present invention has been made in view of the above problems, and an object of the present invention is to improve the ground at the entrance of the reaching shaft and to perform a process such as injection of a chemical solution without the need for processing into the reaching shaft. It is an object of the present invention to provide a method of taking out a shield excavator from a reaching shaft, which can prevent the backing material and groundwater from flowing out and can use the shield excavator as it is for the next tunnel excavation.

[0006]

In order to achieve the above object, a method of removing a shield excavator from an attainable shaft according to the present invention is provided. The tail plate is detachably connected and the shield excavator is excavated with the tail seal of the tail plate slidingly contacting the outer peripheral surface of the lining segment while covering the segment assembled in this tail plate on the excavation wall surface. When the shield excavator reaches the reaching shaft, the tail plate is separated from the skin plate, and the tail plate is left in the excavated ground with the front end of the tail plate facing the reaching shaft from the wellhead. It is characterized by the following.

[0007] In the above method, the invention according to claim 2 is to extrude the shield excavator into the reaching shaft while pressing the ring-shaped wellhead packing attached to the wellhead against the outer peripheral surface of the skin plate of the shield excavator. The tail plate taken out and cut off is left in the excavated ground with the wellhead packing pressed against the outer peripheral surface of the front end.

[0008]

[Function and effect] A shield excavator with a tail plate detachably connected to the rear end of the skin plate excavates a tunnel in soft ground such as stagnant gravel ground from the starting side toward the reaching shaft from the starting side, and the tail plate Assemble the segments in the inside of the excavator. Cover the excavation wall with the segment and inject backing material into the gap between the excavation wall and the lining segment to prevent infiltration of groundwater and collapse of the ground. The shield excavator presses the tail seal attached to the inner peripheral surface of the tail end of the tail plate against the outer peripheral surface of the lining segment, and the filler and groundwater enter the cabin through the gap between the skin plate and the excavation wall. When the shield excavator reaches the reaching shaft, the outer peripheral surface of the skin plate is made to protrude into the reaching shaft while being pressed against the packing mounted on the wellhead.

When the shield excavator is advanced into the reaching shaft until the skin plate of the shield excavator projects from the wellhead into the reaching shaft, the tail plate is separated from the skin plate to take out the shield excavator, and the tail plate is taken out. Is left in the excavated ground with its front end facing the reaching shaft from the wellhead. In this state, since the outer diameter of the tail plate is formed to be the same as the outer diameter of the skin plate of the shield excavator, the wellhead packing can be strongly pressed against the outer peripheral surface of the front end thereof, and therefore, the shield As in the case of taking out the excavator, it is possible to reliably prevent the filler and the groundwater from entering the reaching shaft from the wellhead through the gap between the outer peripheral surface of the tail plate and the excavation wall surface.

Further, the tail plate, which is left buried in the excavated ground, has a tail seal mounted on the inner peripheral surface at the rear end thereof pressed against the outer peripheral surface of the lining segment. It is possible to reliably prevent the filling material and groundwater filling the gap between the engineering segment and the groundwater from flowing out of the pit into the reaching shaft, and also to prevent the groundwater and the filling material from flowing toward the reaching shaft. There is no danger that the excavated wall will collapse. Therefore, it is not necessary to perform a chemical solution injection treatment at the entrance of the reaching shaft unlike the related art, and the tunnel construction can be performed efficiently. Also,
The shield excavator removed in the arrival shaft can be used for the next tunnel construction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a specific embodiment of the present invention will be described.
A drive motor is provided at the front end of the cylindrical skin plate 1a.
A circular cutter plate 1b rotated by 1c is rotatably supported, and a plurality of propulsion jacks 1d are mounted at regular intervals in the circumferential direction in the rear portion of the skin plate 1a. This shield excavator 1 is used
When the tunnel T is excavated from the starting shaft (not shown) toward the reaching shaft 11, the skin plate 1 a
A short tubular tail plate 2 made of a steel plate having the same outer diameter as the outer diameter of the skin plate 1a is detachably connected to the rear end. A tail seal 3 is mounted on the inner peripheral surface of the rear end of the tail plate 2 in a ring shape over the entire periphery.

In order to detachably connect the skin plate 1a and the tail plate 2, the front edge of the tail plate 2 may be temporarily welded to the rear edge of the skin plate 1a so as to be detachable. As shown in FIG. 1, ring-shaped flange portions 1e and 4 bent inward are provided at the rear end of the skin plate 1a and the front end of the tail plate 2, respectively, and these flange portions 1e and 4 are joined. Alternatively, a structure in which the bolts and nuts 5 are detachably connected to each other may be used.

As described above, the tunnel T is excavated by the shield excavator 1 having the tail plate 2 detachably connected to the rear end of the skin plate 1a, and the segment 6 is covered on the excavated wall surface 12. The segment 6 is assembled in a ring shape in the tail plate 2, and the spreader jack 1 d is extended while pressing the spreader of the propulsion jack 1 d against the front end face of the assembled segment 6 to receive the reaction force on the lining segment S. At the same time, the shield excavator 1 is excavated by rotating the circular cutter plate 1b. When a certain length of excavation is performed, the propulsion jack 1d is contracted, the segments 6 are assembled again in the tail plate 2 into a ring shape, and connected to the previously assembled segments 6 for one ring. By repeating this operation, the excavation wall 12
Perform segment lining.

In addition, a backing material 7 is injected into the gap between the lining segment S and the excavation wall surface 12 from the inside of the tunnel through an injection hole (not shown) formed in the segment 6 to collapse the excavated ground. Digging lining segment S
12 is supported via the backing material 7. On the other hand, tail plate 2 connected to skin plate 1a of shield excavator 1
Moves the tail seal 3 attached to the inner peripheral surface of the rear end portion thereof into pressure with the outer peripheral surface of the lining segment S to prevent the backing material 7 from entering the inside of the machine while moving forward integrally with the shield excavator 1. I do.

When the shield excavator 1 reaches the reaching shaft 11 while excavating the tunnel T by the shield excavator 1 and lining the segment 6 on the excavation wall surface 12, the tail plate is cut from the skin plate 1a of the shield excavator 1. The plate 2 is cut off, the shield excavator 1 is taken out into the reaching shaft 11, and the tail plate 2 is left in the excavation wall.

The method of taking out the shield excavator 1 will be described in detail. A ring-shaped wellhead packing 8 having an inner diameter smaller than that of the skin plate 1a is attached to the entrance 13 of the reaching shaft 11, and the shield excavator 1 When the shaft 11 reaches the shaft 11, the outer peripheral surface of the skin plate 1a is pressed against the wellhead packing 8, so that the backing material 7 and groundwater enter the reaching shaft 11 from the gap between the outer peripheral surface of the skin plate 1a and the excavation wall 12. To extend the propulsion jack 1d while preventing
Push the shield excavator 1 into 11.

When the shield excavator 1 is entirely pushed into the reaching shaft 11, the skin plate 1a of the shield machine 1
The front end of the tail plate 2 connected to the rear end of the
Reach 13 At this time, since the tail plate 2 is formed to have the same outer diameter as the skin plate 1a, the wellhead packing 8 is formed.
Is pressed against the outer peripheral surface of the tail plate 2 with the same pressing force as the outer peripheral surface of the skin plate 1a, and the backing material 7 and groundwater reach the arrival shaft 11 from the gap between the tail plate 2 and the excavated wall surface 12. Intrusion can be prevented.

As described above, when the shield excavator 1 is pushed out to the position where the outer peripheral surface of the front end of the tail plate 2 is pressed against the wellhead packing 8, the connection between the skin plate 1a of the shield excavator 1 and the tail plate 2 is established. Unwind and disconnect the shield excavator 1 and take it out into the reaching shaft 11. In addition,
The shield excavator 1 is taken out while assembling a support base (not shown) in the arrival shaft 11 and supporting the shield excavator 1 on this support base.

On the other hand, the skin plate of the shield excavator 1
As shown in FIG. 2, the tail plate 2 separated from 1a is left buried in the excavated ground with its front end opening facing the pit 13 of the reaching shaft 11, and the rear end inner peripheral surface is By keeping the attached tail seal 3 in pressure contact with the outer peripheral surface of the lining segment S, the backing material 7 and the groundwater are prevented from flowing into the reaching shaft 11. The front end of the tail plate 2 is integrally fixed to and supported by a fixing jig 14 fixed around the entrance 13 of the reaching shaft 11 as necessary.

[Brief description of the drawings]

FIG. 1 is a simplified longitudinal side view showing a state in which a shield excavator is pushed into a reaching shaft,

FIG. 2 is a simplified vertical sectional side view showing a state where a shield excavator is separated from a tail plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield excavator 1a Skin plate 2 Tail plate 3 Tail seal 6 Segment 7 Backing material 8 Well packing 10 Water-bearing gravel ground 11 Reaching shaft 12 Drilling wall 13 Wellhead

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-31594 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 9/06 301

Claims (2)

(57) [Claims] 1. A tail plate having the same outer diameter as the skin plate is detachably connected to a rear end of the skin plate of the shield excavator, and a segment assembled in the tail plate is covered on the excavation wall while covering the segment. The shield excavator is excavated while the tail seal of the tail plate is in sliding contact with the outer peripheral surface of the machining segment, and when the shield excavator reaches the reaching shaft, the tail plate is separated from the skin plate, and the front end of the tail plate is cut off. Removing the shield excavator from the arrival wellhead, wherein the tail plate is left in the excavation ground while the tailplate faces the inside of the arrival shaft from the wellhead. 2. A shield-shaped excavator is pushed out into a reachable shaft while a ring-shaped wellhead packing mounted on the wellhead is pressed against an outer peripheral surface of a skin plate of the shielded excavator, and the separated tail plate is moved to the front end thereof. 2. The method for removing a shield excavator from a reaching wellhead according to claim 1, wherein the wellhead packing is left in the excavation ground while being pressed against the outer peripheral surface of the part.