JP3937391B2 - Joining method between existing underground structure and new shield tunnel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for joining an existing underground structure such as an existing shield tunnel and a new shield tunnel, and more particularly, to a technique for providing an earthquake countermeasure to these joints.
[0002]
[Prior art]
As a method of joining a new shield tunnel constructed with a shield machine under excavation to the side of the existing shield tunnel and docking both, the shield machine has been used in the vicinity of the junction with the existing shield tunnel. Stop and form a ground improvement zone between the tip of the shield machine and the joining point, then penetrate the ground improvement zone from the inside of the shield machine and the tip is on the outer surface of the existing shield tunnel at the joining point After installing the penetrating cylindrical penetrating ring, the penetrating machine main body and the existing shield tunnel were connected to each other, and the penetrating ring and the penetrating machine body were combined.
[0003]
In this case, the penetration ring was rigidly coupled to both the new shield tunnel and the existing shield tunnel on the side of the excavator main body by cast-in-place concrete that is subsequently cast on the inner surface side.
[0004]
However, such a conventional method for joining an existing shield tunnel and a new shield tunnel through a shield machine has technical problems described below.
[0005]
[Problems to be solved by the invention]
That is, in the joining method in which the penetrating ring interposed between the existing shield tunnel and the new shield tunnel coupled to the side thereof is rigidly coupled to both sides, the vibration behavior of the existing shield tunnel and the new shield tunnel differs during an earthquake. Therefore, stress concentration tends to occur at these joint portions.
[0006]
If stress concentration occurs in such a joint, it will cause cracks or breakage in the joint, and if such a defect occurs in the joint, this part becomes water, causing a water outage accident or ground collapse. There is a possibility that it will be connected after the fact, and there has been a problem that it takes a lot of time and money to repair such defects.
[0007]
The present invention has been made in view of such conventional problems, and the purpose of the present invention is to concentrate stress at the joint between the existing underground structure and the newly installed shield tunnel during an earthquake. It is to provide a bonding method that does not occur.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, when joining an existing underground structure such as an existing shield tunnel and a new shield tunnel constructed by a shield machine provided with a drilling part on the tip side of the machine body , the shield The excavator is stopped in the vicinity of the junction point with the existing underground structure, and penetrates the ground improvement zone formed between the tip of the shield excavator and the junction point from the inside of the shield excavator. The penetrating ring has a tip that reaches the outer surface of the existing underground structure at the joining point, and then communicates between the excavator body and the existing underground structure, and the penetrating ring and the excavator body through the door, through the bonding method of bonding with said new shield tunnel and the existing underground construction, the flexible structure between said penetration ring and the shield machine main body A method of joining an existing underground structures make and new shield tunnel, the flexible structure has an outer peripheral side is fixed to the inner surface of the shield machine main body, and interposed sealing gasket on the inner peripheral side, An outer ring plate slidably contacting the outer periphery of the penetrating ring, an inner ring plate slidably contacting the inner surface of the penetrating ring with a seal packing on the outer peripheral side, and one end side fixed to the inner surface of the main body of the excavator, Abutting against the end face of the penetrating ring to prevent its retreat, and a receding prevention plate for supporting the inner ring plate from the inside, and between the penetrating ring and the peripheral surface of the inner and outer ring plates. It was composed of a hydrophilic polyurethane-based or chloroprene-based water-expandable sealing material filled in the injection space .
[0009]
According to the joining method of the existing underground structure and the new shield tunnel configured as described above, a flexible structure is provided between the penetration ring and the excavator main body where the coupling portion between the existing underground structure and the new shield tunnel is located. Since the part is interposed, both the existing structure and the new shield tunnel can behave independently with respect to the earthquake motion without affecting the other.
[0010]
As a result, it is possible to avoid the occurrence of stress concentration at the joint between the existing underground structure and the new shield tunnel during an earthquake.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 1 to 8 show an embodiment of a method for joining an existing underground structure and a new shield tunnel according to the present invention.
[0014]
In the joining methods shown in these drawings, the existing underground structure to which the new shield tunnel 10 is joined is the existing shield tunnel 12, and the new shield tunnel 10 is docked on the side surface on the central axis of the existing shield tunnel 12. The present invention is applied in the case of making them.
[0015]
The existing shield tunnel 12 is formed in a circular cross section by assembling the segments 12a into an annular shape. The shield machine 14 for constructing the new shield tunnel 10 has a cylindrical skin plate (digging machine body) 16 having both ends opened.
[0016]
A face plate 18 having an excavation bit is rotatably installed on the front end side of the skin plate 16, and the natural plate is excavated by rotating the face plate 18 with a hydraulic motor (not shown). It is an excavation part of the excavator 14.
[0017]
Further, on the rear side of the skin plate 16, as the shield machine 14 digs, the segments 20 are sequentially assembled in an annular shape, and the newly assembled shield tunnel 10 is connected by connecting the annularly assembled segments 20 in the axial direction. Is built.
[0018]
Inside the skin plate 16, a plurality of shield jacks 22 that take a reaction force on the segment 20 and dig forward are provided at predetermined intervals in the circumferential direction.
[0019]
The face plate 18 has a built-in copy cutter 24 that appears and disappears in the radial direction. By digging the copy cutter 24 by projecting, the outside of the face plate 18 having an outer diameter smaller than the diameter of the skin plate 16 is obtained. It is configured to be able to excavate to a diameter substantially the same as the diameter of the skin plate 16.
[0020]
A cylindrical penetrating ring 26 is installed inside the skin plate 16. The penetration ring 26 of the present embodiment is a cylindrical shape having a predetermined length opened at both ends. As shown in an enlarged view of the main part in FIG. It is installed so as to be able to protrude and retract from a slit hole 30 formed through the fixed ring beam 28.
[0021]
In this case, the protruding position of the penetrating ring 26 is located outside the outer end of the face plate 18 so that mutual interference between the penetrating ring 26 and the face plate 18 due to the protruding and projecting can be avoided.
[0022]
The penetrating ring 26 may be formed in a cylindrical shape as a whole, or may be formed by combining arcuate curved plates obtained by dividing the cylinder into a plurality of circumferential directions. A seal portion 37 composed of outer and inner ring plates 32 and 34 and a seal packing 36 is provided on the distal end side of the penetrating ring 26.
[0023]
As shown in detail in FIG. 3, the seal portion 37 has outer and inner ring plates 32 provided with projections 32 a and 34 a protruding in two steps at predetermined intervals in the axial direction. 34 is disposed so that the projections 32a and 34a face each other, and the penetration ring 26 is inserted between the projections 32a and 34a facing each other, and the seal packing is provided between the projections 32a and 34a and the inner and outer surfaces of the penetration ring 26, respectively. 36 is interposed.
[0024]
The outer ring plate 32 extends along the outer peripheral surface of the penetration ring 26, and the outer peripheral end thereof is fixed to the inner peripheral surface of the skin plate 16. The inner ring plate 34 extends along the inner peripheral surface of the penetrating ring 26, and its side end surface is fixed to the side surface of the ring beam 28.
[0025]
In the seal portion 37 configured as described above, the outer and inner ring plates 32 and 34 provided with the protrusions 32a and 34a protruding in two steps and the ring beam 28 are used to form the inner surface of the outer ring plate 32 and the inner ring plate 34. Two rows of annular injection spaces 38 are formed between the outer surface of the inner ring and the inner and outer surfaces of the penetrating ring 26, and an injection conduit 40 with a valve is provided in communication with each of the annular injection spaces 38.
[0026]
On the other hand, inside the penetration ring 26, a cleaning tube 42 opened to the tip side is incorporated. In addition, an expansion / contraction end of an extrusion jack 44 whose body is fixed to the ring beam 28 is coupled to the rear end side of the penetrating ring 26.
[0027]
When joining the new shield tunnel 10 to the existing shield tunnel 12, the shield machine 14 that has been dug is stopped in the vicinity of the junction point of the existing shield tunnel 12 as shown in FIG. 1.
[0028]
Next, a ground improvement zone 46 is formed between the tip of the shield machine 14 and the junction point of the existing shield tunnel 12. The ground improvement zone 46 uses a freezing or chemical injection method from the existing shield tunnel 12 or shield machine 14 to stabilize the surrounding ground to be docked. The ground improvement zone 46 may be formed from the ground side before the shield machine 14 reaches the joining point.
[0029]
When the ground improvement zone 46 is formed, next, as shown in FIG. 4, the tip penetrates the ground improvement zone 46 from the inside of the shield machine 14 and the tip reaches the outer surface of the existing shield tunnel 12 at the joining point. The penetration ring 26 is installed so as to.
[0030]
When the penetration ring 26 is installed in such a state, an extrusion jack 44 provided in the shield machine 14 is used. When the expansion / contraction plunger of the extrusion jack 44 shown in FIG. Pushed forward. When the penetration ring 26 is pushed out and brought into contact with the side surface of the existing shield tunnel 12, the cleaning liquid is ejected from the cleaning pipe 42.
[0031]
Next, the face plate 18 and the bulkhead of the shield machine 14 are removed, the segment 12a at the joining point of the existing shield tunnel 12 is removed, and the skin plate 16 and the existing shield tunnel 12 are communicated with each other.
[0032]
When such communication work is completed, in the case of the present embodiment, the flexible structure 48 is provided at the coupling portion between the newly installed shield tunnel 10 and the existing shield tunnel 12.
[0033]
The flexible structure 48 is formed between the peripheral surface of the penetration ring 26 located in the skin plate 16 and the inner surface of the skin plate 16 by using the seal portion 37 described above.
[0034]
That is, the flexible structure 48 of the present embodiment includes outer and inner ring plates 32 and 34, a retraction preventing plate 50, a retaining plate 52, and a sealing material 54. The outer ring plate 32 is fixed to the inner surface of the skin plate 16 on the outer peripheral side, and is in sliding contact with the outer periphery of the penetrating ring 26 via a seal packing 36 on the inner peripheral side.
[0035]
The inner ring plate 34 is in sliding contact with the inner surface of the penetrating ring 26 with a seal packing 36 interposed on the outer peripheral side. One end side of the receding prevention plate 50 is fixed to the inner surface of the skin plate 16, and comes into contact with the end surface of the penetrating ring 26 via a retaining plate 52 to prevent its receding.
[0036]
Further, the retreat prevention plate 50 has an inner end extending along the inner surface of the inner ring plate 34, and supports the inner ring plate 34 from the inner side. The retaining plate 52 is fixed to the rear end of the penetrating ring 26 and prevents the penetrating ring 26 from slipping forward.
[0037]
The sealing material 54 is, for example, a liquid material of a water-expandable sealing material such as a hydrophilic polyurethane system or a chloroprene system, and is injected and filled into the annular injection space 38 via the injection pipe 40. In the flexible structure 48 configured as described above, the sealing performance is ensured by the sealing material 54 and the seal packing 36.
[0038]
Further, the outer and inner ring plates 32, 34 provided with the protrusions 32a, 34a protruding in two stages are arranged so that the protrusions 32a, 34a face each other, and the penetrating ring 26 is provided between the facing protrusions 32a, 34a. Since the seal packing 36 is interposed between the protrusions 32a and 34a and the inner and outer surfaces of the penetration ring 26, the penetration ring 26 compresses and deforms the seal packing 36, thereby inserting the penetration ring 26. Is eccentric with respect to the new shield tunnel 10, and flexibility is obtained.
[0039]
The degree of eccentricity or flexibility in this case can be changed as appropriate according to the size of the gap between the protrusions 32a, 34a and the inner and outer surfaces of the penetrating ring 26.
[0040]
If the flexible structure 48 is interposed between the penetration ring 26 and the skin plate 16 as described above, then, as shown in FIG. A cast-in-place concrete layer 56 is formed on the inner peripheral surface side of the ring 26 to perform lining.
[0041]
In this case, the cast-in-place concrete layer 56 is divided and formed so as to exclude the flexible structure portion 48, and the end of one concrete layer 56 is integrated with the segment 12a of the existing shield tunnel 12, and the other The end of the concrete layer 56 is integrated with the segment 20 of the new shield tunnel 10.
[0042]
In the portion where the cast-in-place concrete layer 56 is divided, a stretchable metal cover 58 as shown in FIG. 8 is installed, and when this cover 58 is installed, the newly installed shield tunnel 10 and the existing shield tunnel 12 are joined. Is completed.
[0043]
Now, according to the joining method configured as described above, the flexible structure 48 is interposed between the penetration ring 26 and the skin plate 16 positioned at the joint portion between the newly installed shield tunnel 10 and the existing shield tunnel 12. Therefore, both the newly installed shield tunnel 10 and the existing shield tunnel 12 can behave independently with respect to the earthquake motion without affecting the other.
[0044]
As a result, it is possible to avoid the occurrence of stress at the joint portion between the newly installed shield tunnel 10 and the existing shield tunnel 12 at the time of an earthquake, thereby eliminating the cause of cracks or destruction of the joint portion. .
[0045]
In the above embodiment, the existing shield tunnel 12 is exemplified as the existing underground structure. However, the present invention is not limited to the case where the new shield tunnel 10 is joined to the existing shield tunnel 12, but the new shield tunnel 10 is installed in the reach shaft. It can also be applied to the case of joining.
[0046]
【The invention's effect】
As described above in detail, according to the joining method of the existing underground structure and the newly installed shield tunnel according to the present invention, no stress is generated at the joint portion between the existing underground structure and the newly installed shield tunnel.
[Brief description of the drawings]
FIG. 1 is a cross-sectional explanatory view of an initial state of a method for joining an existing underground structure and a newly installed shield tunnel according to the present invention.
FIG. 2 is an enlarged view of a main part of FIG.
FIG. 3 is an enlarged view of a portion A in FIG.
FIG. 4 is an explanatory diagram for a main part of a step performed subsequent to FIG. 1;
FIG. 5 is an explanatory diagram for a main part of a step performed subsequent to FIG. 4;
6 is an enlarged view of a portion B in FIG.
FIG. 7 is an explanatory diagram for a main portion of a step performed subsequent to FIG. 5;
FIG. 8 is an explanatory diagram for a main part of a step performed subsequent to FIG. 6;
[Explanation of symbols]
10 New shield tunnel 12 Existing shield tunnel (underground structure)
14 Shield machine 16 Skin plate (main machine)
18 face plate 20 segment 22 shield jack 26 penetration ring 32 outer ring plate 34 inner ring plate 38 annular injection space 44 extrusion jack 46 ground improvement zone 48 flexible structure

Claims (1)

When joining an existing underground structure such as an existing shield tunnel and a new shield tunnel constructed with a shield machine provided with an excavation part on the tip side of the excavator body , the shield machine is connected to the existing underground structure. And in the vicinity of the joining point, and through the ground improvement zone formed between the tip of the shield machine and the joining point from the inside of the shield machine, the tip is the said of the joining point After installing the penetrating ring that reaches the outer surface of the existing underground structure, the excavator body and the existing underground structure are communicated with each other, and the existing underground unit is connected via the penetrating ring and the excavator body. the joining method of attaching said new shield tunnel and structures, the existing underground construction interposing the flexible structure during the penetration ring and the shield machine main body and the new A method of joining the shield tunnel,
The flexible structure includes an outer ring plate fixed on the inner surface of the main body of the excavator body, a seal packing on the inner peripheral side, a sliding contact with the outer periphery of the penetrating ring, and a seal on the outer peripheral side. An inner ring plate in sliding contact with the inner surface of the penetrating ring with a packing interposed therebetween;
One end side is fixed to the inner surface of the main body of the excavator, abutting against the end surface of the penetrating ring to prevent its retreat, and a retraction prevention plate for supporting the inner ring plate from the inner side,
An existing underground structure comprising a hydrophilic polyurethane-based or chloroprene-based water-expandable sealing material filled in an injection space formed between the penetrating ring and the peripheral surfaces of the inner and outer ring plates Bonding method of objects and new shield tunnel.

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