JP4374538B2 - Tunnel constriction lining structure and construction method thereof - Google Patents

Description

  The present invention relates to a lining structure of a tunnel constricted portion and a construction method thereof.

At the tunnel junction where the two tunnels merge or branch, the cross-sectional shape is a glasses type. In this tunnel junction, when the constricted lining part where the tunnels join each other is subjected to earth and water pressure from the outside of the lining, a large bending moment is generated outside the constricted part as compared with a normal circular tunnel. Therefore, in order to reinforce the lining structure of the constricted portion, it is common to employ a reinforcing structure in which a middle pillar is provided in the vertical direction inside the tunnel (see, for example, Patent Document 1).
In a case where the cross-sectional shape is a glasses-type tunnel such as a branching part or a junction part of a road ramp part, two shield tunnels are constructed by directly joining them underground using a shield method. In the case of this branched and merged shield tunnel, it is not possible to construct a center pillar because of the structure for use. Therefore, in this case, it is necessary to increase the load resistance of the constricted part of the eyeglass-type tunnel without installing a middle pillar.Therefore, it is necessary to increase the segment girder height or to connect the beam extending in the tunnel axis direction to the constricted part. The lining of high-strength structure is constructed by providing it in the segment.
In addition, there is another method of reinforcing the lining structure of the glasses-type tunnel by attaching horizontal beams to the upper and lower parts of the tunnel crossing direction as another lining reinforcement method without installing the middle pillar.
Japanese Patent Laid-Open No. 4-93493

However, in a glasses-type tunnel that cannot construct a center pillar, the method of increasing the girder height of the segment and making the lining a high-strength structure increases the cost of the segment and shield machine because the tunnel cross section increases. There's a problem. For example, in the case of a tunnel having a segment girder height of about 600 mm in a normal cross section, a design girder for the segment girder height in a glasses-type tunnel requires a double or more girder height. In this case, if the construction limit is secured in the sky inside the tunnel, the shield excavation diameter increases, and the costs associated with the shield excavator and construction increase accordingly.
In addition, the method of extending the beam in the tunnel axis direction to make the lining a high-strength structure increases the cost of the segment because the constricted segment has a complicated and special structure.
In addition, the method of reinforcing by installing a horizontal beam in the tunnel mine has a problem that the construction is large and the construction period is prolonged because the temporary support column and the horizontal beam are exchanged and installed in a narrow space.

  The present invention has been made in view of the above-described problems. For example, in a tunnel lining structure having a constricted portion like a tunnel whose cross-sectional shape is a glasses shape, the cost of a reinforcing structure can be reduced. An object of the present invention is to provide a lining structure for a tunnel constriction and a construction method thereof.

In order to achieve the above object, the tunnel constriction lining structure according to the present invention is a tunnel lining structure having a constricted portion at the lining location, and a reinforcing structure formed along the outside of the constricted portion is provided. The tension member is circumscribed in the tunnel axial direction, circumscribed by the constricted portion. The tension member is penetrated in the tunnel transverse direction, and both ends of the tension member are fixed to the tunnel .
In the present invention, the compressive force generated outside the tunnel constriction can be received by the reinforcing structure. For this reason, it is not necessary to make a high-strength lining with a large cost such as increasing the segment girder height, and the cost of the reinforcing structure can be reduced. Further, the reinforcing structure and the tunnel can be firmly connected, and the tensile force generated in the inner direction of the constricted portion can be relaxed.

In addition, the method for constructing a tunnel constriction according to the present invention is such that a concrete block receives a propulsive force from a predetermined working mine by a propulsion method, is propelled by circumscribing the constriction, and a plurality of concrete blocks are added to be continuously reinforced. A first step of constructing the structure, a second step of injecting a filler into the gap between the outside of the constricted portion and the reinforcing structure, and penetrating the tension member through the reinforcing structure, and two ends thereof And a third step of fixing to the tunnel.
In the present invention, since the reinforcing structure can be constructed in a limited work space, not over a wide range, the construction can be simplified and the construction cost can be reduced. Moreover, since the concrete block shape | molded previously is used, a construction period can be shortened.

  According to the present invention, in the tunnel constriction lining structure, the reinforcing structure provided on the outside of the constriction can receive the compressive force applied to the constriction, and the middle pillar is constructed in the tunnel of the glasses-type tunnel. In addition, the cost of the reinforcing structure can be reduced without providing a high-strength structure having a large cost such as increasing the digit height of the segment or installing a beam.

Hereinafter, a tunnel lining structure according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a tunnel at a junction by a branching junction shield method according to an embodiment, FIG. 2 is an enlarged view of a reinforcement structure at a tunnel constriction shown in FIG. 1, and FIG. 3 is a construction process of lining reinforcement shown in FIG. 4 is a cross-sectional view taken along line AA of the lining reinforcement shown in FIG. 3, FIG. 5 is a cross-sectional view taken along line BB, and FIG. 6 is a lining in the lining structure of the tunnel constricted portion according to the embodiment. It is process explanatory drawing of reinforcement construction.
The merge part in the branch and merge shield method according to the present embodiment is a method that does not depend on the open-cut method from the ground, and in the construction to connect two tunnels underground or to branch one tunnel by the shield method. is there. In plan view, the branch line tunnel 2 gradually approaches the left side of the main tunnel 1 and is connected in a Y shape. FIG. 1 shows a cross section of the tunnel junction. As shown in FIG. 1, the main line tunnel 1 is a shield tunnel provided with a circular tubular main line segment 1 a, and the branch line tunnel 2 is provided with a branch line segment 2 a in the same manner as the main line tunnel 1. The tunnel where the main tunnel 1 and the branch line tunnel 2 merge has a constricted portion at the junction of both tunnels 1 and 2, the segment between the constricted portions in the vertical direction is removed and communicated, and the tunnel cross-section is glasses. A glasses-type tunnel 3 having a shape is formed. Further, the main tunnel 1 forms a widened portion 4 that is horizontally extended and widened outward from the right side surface in order to secure the building limit shown by K in FIG.

As shown in FIG. 1, at the intersection where the main line segment 1a and the branch line segment 2a are joined, there are formed constricted portions of approximately V-shape and approximately inverted V-shape at two locations above and below the tunnel. The two constricted portions have an upper constricted portion 5 (constricted portion) on the upper side and a lower constricted portion 6 (constricted portion) on the lower side.
A reinforcing region 7 having a substantially triangular cross section is formed in a space outside the upper constricted portion 5, and the reinforcing region 7 is made of concrete having the same cross sectional shape as the reinforcing region 7 and having a predetermined thickness. A plurality of blocks 8 (concrete blocks) are continuously installed to constitute the reinforcing structure H.
In order to reinforce the lower constricted portion 6, a plurality of earth anchors 9 are installed from the bottom plate portion of the glasses-type tunnel 3 toward the lower outer side. During the construction period of the reinforcing block 8 and the earth anchor 9, a removable first support column 10a and a second support column 10b that support the vertical direction in the glasses-type tunnel 3 are provided.

  The reinforcement block 8 is pre-manufactured at a segment factory or the like and is used by being brought into the mine. The reinforcing blocks 8 are sequentially added by the propulsion method, and the connecting surfaces in the propulsion direction between the reinforcing blocks 8 have an uneven shape and are engaged (see FIG. 3). A gap between the outer side of the upper constricted portion 5 and the reinforcing structure H is filled with a filler 11 such as mortar.

Furthermore, as shown in FIG. 2, in order to fix the reinforcing structure H and the glasses-type tunnel 3, a bar-like tension member 12 such as a steel wire or a steel bar is provided in the tunnel transverse direction. Each reinforcing block 8 is previously provided with a through hole 13 for allowing the tension member 12 to pass therethrough. Excavation hole 1b that penetrates from the inside to the outside of main line segment 1a so as to coincide with the position of the hole of through hole 13 provided in each reinforcing block 8, and excavation hole 2b that penetrates similarly to branch line segment 2a And are provided. Cylindrical fixed tubes 14a and 14b are provided in the respective excavation holes 1b and 2b, and both end portions of the tension member 12 are inserted into and fixed to the fixed tubes 14a and 14b.
Each reinforcing block 8 is arranged in a direction parallel to the propulsion axis direction so as not to interfere with the through-hole 13, and a plurality of water supply holes 15 provided to supply water to the propulsion face are generated at the propulsion face. The earth removal hole 16 for removing earth and sand is provided.

Next, in the tunnel constriction lining structure according to the embodiment, a reinforcing part construction method will be described with reference to the drawings.
First, a temporary first support column 10a and a second support column 10b are built in the reinforcing section of the glasses-type tunnel 3 in the vertical direction in the tunnel, and the earth and water pressure applied to the segments of the glasses-type tunnel 3 is transferred to the upper and lower surfaces of the tunnel. Support in the direction (see FIG. 1).

Next, a method for constructing the reinforcing structure H will be described with reference to the drawings.
In FIG. 3, the propulsion equipment of the reinforcement block 8 forming the reinforcement structure H is provided with a excavation mechanism R provided on the face of the reinforcement block 8 leading by the propulsion and the excavation mechanism R with a propulsive force. Propulsion equipment related to water supply and soil discharge for R to function is composed of a propulsion mechanism S provided on the extension side.

  The excavation mechanism R is a mechanism for excavating the face, as shown in FIGS. 3 and 5, and includes a skin plate 17 formed in a triangular frame shape surrounding the side of the reinforcing block 8 at the front end of the face, and the skin plate 17. The face plate 18 is formed on the inner side of the face plate 18 and the excavating blade 19 is provided at the peripheral edge of the face plate 18 and projects in the propulsion direction. Further, the face plate 18 includes a high-pressure injection unit 20 for excavating a natural mountain by rotating and jetting high-pressure water around the propulsion direction, and a sediment transport outlet 21 for discharging the excavated earth and water in the direction of the propulsion mechanism S. Is provided.

  As shown in FIGS. 3 and 4, the propulsion mechanism S is installed between the reaction force wall 22 provided facing the rear end surface of the reinforcement block 8, and between the reaction force wall 22 and the reinforcement block 8, and generates propulsive force. A propulsion jack 23 to be generated, a water feed pipe 24 inserted into the water feed hole 15 of the reinforcement block 8 and connected to the high-pressure jet section 20 of the propulsion face, a screw inserted into the earth discharge hole 16 of the reinforcement block 8, etc. The earth and sand collection mechanism 25 is comprised. And the propulsion mechanism S is installed in the propulsion work pit 26, and propulsion work is performed.

Next, the preparatory work performed in the construction of the reinforcing structure H will be described based on FIGS.
First, a plurality of curved pipe roofs 27 having a circular arc shape in the transverse direction of the tunnel are formed outward from the top of the tunnel of the glasses-type tunnel 3 to form a roof structure having a horizontal semi-cylindrical shape. 26 is constructed. As shown in FIG. 3, in the propulsion work pit 26, the excavation mechanism R inserts and fixes the face of the reinforcing block 8 installed at the head in the propulsion direction inside the skin plate 17 of the excavation mechanism R. . The reaction wall 22 is provided at a position facing the rear end of the reinforcing block 8, and a propulsion jack 23 is provided between the rear end surface of the reinforcing block 8 and the reaction wall 22. As a result, it is possible to propel the reaction force wall 22 with a propulsion reaction force.
Further, a water supply pipe 24 is inserted into a water supply hole 15 provided in the reinforcing block 8, the tip of the water supply pipe 24 is connected to the high-pressure injection unit 20, and high-pressure water is sent to the face. Also, an earth and sand recovery mechanism 25 such as a screw is inserted into the earth discharge hole 16, and the earth and sand excavated by the face and the water used for the excavation are discharged from the earth and sand outlet 21, and are passed through the earth and sand recovery mechanism 25. It is carried out to the propulsion work pit 26 side.
The work up to this point is the preparation work for the propulsion work.

Next, the steps after the promotion will be described with reference to FIG. 3, FIG. 5, and FIG.
In the first step shown in FIG. 3, when the reinforcing block 8 is pushed out in the direction of the arrow T by the propulsive force of the propulsion jack 23, the excavating blade 19 of the excavating mechanism R is embedded in the ground in the propulsion direction, as shown in FIG. A natural ground is excavated by high-pressure water that is rotated and jetted around the propulsion shaft from the high-pressure jet unit 20. When the promotion of the reinforcement block 8 for one block is completed, the reinforcement block 8 to be set next is added between the promotion jack 23 and the rear end surface of the reinforcement block 8, and the same promotion operation as described above is repeated. With the propulsion work, the water supply pipe 24 and the earth and sand recovery mechanism 25 are extended simultaneously with the addition of the reinforcing block 8. In this way, a reinforcing structure H in which a plurality of reinforcing blocks 8 are continuously formed in the propulsion direction is constructed (see FIG. 6A).

Next, in the second step shown in FIG. 6B, a filler 11 such as mortar is injected into the gap between the outside of the upper constricted portion 5 and the reinforcing structure H.
Subsequently, in the third step shown in FIG. 6 (c), the excavation holes 1 b and 2 b are formed from the inside to the outside of the segments 1 a and 2 a of the glasses-type tunnel 3 so as to coincide with the positions of both end faces of the through-hole 13. The fixed pipes 14a and 14b are installed in both of the excavation holes 1b and 2b.
Finally, as a fourth step, the through hole 13 and the fixed pipes 14a and 14b form one continuous hole in the tunnel transverse direction, and the tension member 12 is inserted into the hole, and the gap in the hole is formed by the grout. Filled (see FIG. 2). Thereby, the reinforcement structure H is fixed to the main line segment 1a and the branch line segment 2a.

  With the above operation, the lining reinforcement of the upper constricted portion 5 is constructed. Thereafter, the propulsion mechanism S is removed, and the propulsion work pit 26 is closed by filling with mortar or the like. In addition, during the process steps so far, the earth anchor 9 is constructed from the inside of the negative tunnel 3 to the lower outer side, and the lower constricted portion 6 is reinforced. Finally, the first support column 10a and the second support column 10b that have been installed as temporary columns during the lining reinforcement period are removed.

The bending moment generated in the upper constricted portion 5 due to the earth and water pressure that the glasses-type tunnel 3 receives from the outside of the lining acts on the upper portion of the upper constricted portion 5 in the outward direction. On the other hand, at a position near the intersection of the two tunnels in the lower part of the upper constricted part 5, a bending moment (tensile force) acts in the inner direction opposite to the compressive force. By applying the lining reinforcement according to the present embodiment, the compression force generated in the upper constricted portion 5 is handled by the constructed reinforcing structure H. Since the reinforcing structure H is made of concrete that is resistant to compressive force, it is effective against the compressive force received from the lining of the upper constricted portion 5.
The tension member 12 can firmly connect the reinforcing structure H and the glasses-type tunnel 3. And the tension | tensile_strength member 12 can relieve | moderate the tension | tensile_strength force which acts on the inner side direction of the upper constriction part 5 by being tension | tensile | stretched in a direction opposite to tensile force.

In the lining structure of the tunnel junction portion according to the present embodiment, by installing the reinforcing structure H outside the upper constricted portion 5, there is no need to construct a high-strength lining structure with a high cost as in the prior art. The overall construction cost can be reduced. Furthermore, the eyeglass-type tunnel 3 in which the reinforcing structure H is constructed can have a structure in which no middle pillar is installed.
Further, since the reinforcement block 8 is manufactured in advance in a block shape that is easy to carry in and install, the propulsion method can be adopted in the propulsion work pit 26 and is constructed within a limited work range not over a wide range. be able to. Therefore, since the construction is simplified, the construction period can be shortened and the construction cost can be reduced.

As mentioned above, although embodiment of the lining structure of the tunnel constriction part by this invention was described, this invention is not limited to said embodiment, It can change suitably in the range which does not deviate from the meaning.
For example, in the above embodiment, the reinforcing structure H is provided in the glasses-type tunnel 3 of the shield tunnel. However, the tunnel is not limited to the shield tunnel as long as the tunnel has a constricted portion at the lining portion. For example, it may be applied to a NATM tunnel. In short, it is only necessary to obtain the desired effects in the present invention. Then, although two tunnels are used in the present embodiment, the present invention is not limited to only two tunnels arranged in parallel, and even when three or four tunnels are arranged in parallel, they are adjacently arranged in parallel. Two tunnels may be used. Furthermore, these two tunnels do not have to be constructed separately, and may be constructed at the same time. It is sufficient if it has a constricted portion in the cross-sectional shape.
Further, in the above embodiment, the reinforcing structure H is provided to reinforce the upper constricted portion 5, but the reinforcing effect similar to that of the upper constricted portion 5 instead of the ground anchor 9 is also provided in the reinforcement of the lower constricted portion 6. You may apply the reinforcement structure H which can obtain these.
Moreover, although the reinforcement block 8 is a concrete block, it is not limited to this, Even if it constructs | assembles the structure which can acquire the same effect by construction, such as placing concrete in the reinforcement area | region 7, after excavation Good. And in embodiment, the through-hole 13 is attached for every reinforcement block 8, and the tension member 12 is penetrated, but every other block may be sufficient and the installation space | interval of the tension member 12 is arbitrary.
Furthermore, in the above-described embodiment, the propulsion work is one-sided push construction from one propulsion work pit 26. However, the push work pits 26 may be provided at two locations on both ends of the reinforcing section, and double-push construction may be performed. Alternatively, a propulsion work pit 26 may be provided in the middle of the reinforcing section, and propelled in both directions from there.

FIG. 5 is a cross-sectional view of the tunnel at the junction of the branch and junction shield method, which relates to a tunnel constriction lining structure according to an embodiment of the present invention. It is an enlarged view of the reinforcement structure in the tunnel constriction part shown in FIG. It is a figure which shows the construction process of the reinforcement structure in the tunnel constriction part shown in FIG. It is the sectional view on the AA line of the reinforcement structure in the tunnel constriction part shown in FIG. FIG. 4 is a cross-sectional view taken along line B-B of the reinforcing structure in the tunnel constriction shown in FIG. 3. It is related with the lining structure of the tunnel constriction part by embodiment, Comprising: It is process explanatory drawing of lining reinforcement construction.

Explanation of symbols

1 main tunnel
2 Branch line tunnel 3 Glasses type tunnel 5 Upper constriction (constriction)
6 Lower constriction (constriction)
7 Reinforcement area 8 Reinforcement block (concrete block)
DESCRIPTION OF SYMBOLS 9 Earth anchor 10a 1st support | pillar 10b 2nd support | pillar 11 Filling material 12 Tension | tensile_strength member 13 Through-hole 14a Fixed pipe 14b Fixed pipe 26 Propulsion work pit 27 Curved pipe roof H Reinforcement structure R Excavation mechanism S Propulsion mechanism

Claims (2)

In the tunnel lining structure having a constricted portion at the lining location, a reinforcing structure formed along the outside of the constricted portion is provided in the tunnel axial direction circumscribing the constricted portion ,
In the reinforcing structure, a tension member is penetrated in the tunnel transverse direction,
A tunnel constriction lining structure characterized in that both ends of the tension member are fixed to the tunnel. In the tunnel lining structure with a constricted part at the lining location,
A first step in which a concrete block receives a propulsive force from a predetermined working mine by a propulsion method, is circumscribed by the constricted portion, is propelled, and a plurality of the concrete blocks are added to construct a continuous reinforcing structure;
A second step of injecting a filler into the gap between the outside of the constricted portion and the reinforcing structure;
And a third step of passing the tension member through the reinforcing structure and fixing both ends of the reinforcement member to the tunnel.

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