JP4205615B2 - How to construct a confluence of shield tunnels - Google Patents

Description

  The present invention relates to a method for constructing a junction portion of a shield tunnel that is preferably used for constructing a tunnel including a junction portion / branching portion such as a road tunnel.

In recent years, with the progress of underground use, construction of road tunnels, sewer tunnels, etc. is being carried out in a deep underground space of about 50 m underground. In particular, the shield method is advantageous when building tunnels in underground spaces in urban areas where underground use is advancing.
In the construction of a road tunnel or the like, it is necessary to integrally connect two shield tunnels close to each other at the junction of the main tunnel and a branch tunnel such as a ramp tunnel. In this case, a method of connecting a shield tunnel to a converging part excavated from the road is conceivable, but the exclusive area on the ground is wide in both width and length, which is a serious problem.

Therefore, in order to reduce the exclusive area on the ground, a shaft was installed to introduce a shield machine for the branch tunnel, and the junction was merged with the shield machine for the main tunnel in this shaft, and the junction was excavated. A method of branching is considered. In addition, by using a shield machine provided with protrusions, lining bodies with protrusions formed on the upper and lower sides are installed at the locations where the preceding shield tunnel and the subsequent shield tunnel face each other, and the upper and lower protrusions are respectively provided. A method for joining shield tunnels in which segments between parts are removed and joined is disclosed (for example, see Patent Document 1).
Japanese Patent No. 2755772

  However, in the former method, it is not necessary to excavate the entire range of the merging portion, but it is necessary to excavate the shaft portion, and there is no change to occupying the ground portion. Moreover, as the construction position of the shield tunnel increases, the construction cost increases. In the latter method, it is not necessary to excavate from the ground, but the structure of the shield machine must be made special so as to form the protrusions, which increases the machine cost. Further, in the conventional method, when the main tunnel is in service, it is difficult to construct and join the branch tunnel without stopping the service.

  An object of the present invention is to construct a junction part of a shield tunnel without excavating from the ground and without requiring any ingenuity in the shield machine. In addition, it is to construct the junction part of the shield tunnel while using the main tunnel to be joined.

In order to solve the above-described problems, the invention described in claim 1 is, for example, as shown in FIG. 1, construction of a shield tunnel for constructing a junction between a main tunnel and a branch tunnel respectively constructed by a shield method. In the section of the merge section, the main tunnel and the branch tunnel are dug so as to be close to each other, and a protruding segment comprising an outer frame segment and a movable segment movably disposed therein is provided. Assembling a substantially circular lining including an upper part and a lower part, and then removing a part of the lining that separates the main line tunnel and the branch line tunnel and excavating a natural ground, The moving segment is pushed out from the outer frame segment of the attached segment, and the upper part of the main and branch tunnels and Protrusions are formed on the part, and a steel shell is attached so as to bridge between these protrusions, and the space between the steel shell and the lining is filled with a filler, so that the main tunnel and the branch tunnel lining are integrated. It is characterized in that the envelope of the cross section of the lining composed of the main tunnel, the branch tunnel and the steel shell is substantially circular.
Here, the “substantially circular” refers to an elliptical shape, an oval shape, etc. in addition to a regular circular shape.

In this way, in the section of the junction of the main line tunnel and the branch line tunnel, the main line tunnel and the branch line tunnel are dug so as to be close to each other, and each consists of an outer frame segment and a moving segment movably disposed therein. Assemble a substantially circular lining that includes protruding segments at the top and bottom, and then continue by excavating a natural ground by removing a portion of the lining that separates the main tunnel and the branch tunnel In addition, the moving segment is pushed out from the outer frame segment of the protruding segment to form protrusions at the upper and lower portions of the main line tunnel and the branch line tunnel, and a steel shell is attached so as to be bridged between these protrusions. And filling the space between the lining and the lining of the main tunnel and the branch tunnel. Without digging the ground, without the need for devising the shield machine can be reduced their cost. In addition, the merging part of the shield tunnel can be constructed while using the merged main tunnel.
In addition, by making the envelope of the cross section of the main tunnel, the branch tunnel, and the steel shell lining substantially circular, the cross section of the junction of the main tunnel and the branch tunnel is a substantially circular cross section that is mechanically stable. Therefore, it is suitable for constructing a junction between a main tunnel and a branch tunnel in a deep underground space that receives a large earth pressure.

  According to the first aspect of the present invention, in the section of the junction between the main line tunnel and the branch line tunnel, the main line tunnel and the branch line tunnel are dug so as to be close to each other, and the outer frame segment and each of the outer frame segments are freely movable therein. Assembling a substantially circular lining including protruding segments made up of moving segments arranged in the upper and lower parts, and then removing a part of the lining separating the main tunnel and the branch tunnel, , And the moving segment is pushed out from the outer frame segment of the segment with protrusions to form protrusions at the upper and lower portions of the main tunnel and the branch tunnel, and the steel is bridged between these protrusions. A shell is attached and the space between this steel shell and the lining is filled with a filler, and the main tunnel and the branch tunnel lining are covered. Because be integrated without digging the ground, without the need for devising the shield machine can be reduced their cost. In addition, the merging part of the shield tunnel can be constructed while using the merged main line tunnel.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
The construction method of the junction part of the shield tunnel according to the present embodiment is for digging each of the main tunnel T1 and the ramp tunnel (branch line tunnel) T2 of the road tunnel constructed underground, and for constructing the junction part TJ. Applicable.

  As shown in FIG. 1, the main tunnel T1 is a one-sided three-lane road tunnel provided at a depth of about 50 m underground, and has already started operation. The ramp tunnel T2 is a tunnel provided as an entrance lane and an exit lane of the main tunnel T1.

  The main tunnel T1 and the lamp tunnel T2 are constructed by a standard lining method using a conventional standard shield machine, and the cross section is a standard circular cross section. As a feature of the present invention, as shown in FIG. 1, it is constructed by including protruding segments 3 and 4 at a part of the lining, that is, at the upper and lower portions of the linings 1 and 2.

  As shown in FIGS. 2 and 3, the segment 3 with projections of the lining 1 of the main tunnel T1 is composed of a steel outer frame segment 3b, a moving segment (projection) 3a, and a dummy member. The outer frame segment 3b has a frame shape opened toward the outer side and the inner side of the tunnel, and forms a part of the lining to form a circular cross section of the lining. The upper part of the moving segment 3a is formed in a protruding shape and is accommodated in the outer frame segment 3b. The dummy members 3c and 3d are members that fill a gap between the moving segment 3a and the outer frame segment 3b. By attaching the dummy member 3b, it is possible to prevent water and earth and sand from entering during excavation without using a special tail seal for the shield machine. The structure of the protruding segment 4 of the lining 2 of the branch tunnel T2 is the same as that of the main tunnel T1.

  A joining member 3f for joining the outer segment 3b and the moving segment 3a is attached to the inner side surface of the outer frame segment 3b. Further, a sealing member 3e for stopping water between the outer surface of the moving segment 3a is attached.

  The moving segment 3a can be a free-form protrusion by the dummy member 3d. Since the moving segment 3a and the dummy member 3d have a rectangular shape, they can be easily pushed out of the tunnel and water can be stopped easily.

The procedure of the construction method of the junction part of the shield tunnel of this Embodiment is demonstrated.
In the linings 1 and 2 of the main tunnel T1 and the ramp tunnel T2 constructed so as to be parallel to each other, as shown in FIG. 1 (b), a supporting work 6 is installed so as not to prevent the vehicle from traveling in the main tunnel T1. Install. Further, the ground improvement 7 is applied to the upper and lower ground between the linings 1 and 2 of the main tunnel T1 and the ramp tunnel T2 by injecting ground improvement material, freezing the ground, or the like.

  Then, a part of the segments constituting the linings 1 and 2 between the main tunnel T1 and the ramp tunnel T2 is removed and a natural ground is excavated, so that the two tunnels T1 and T2 are continued in the lateral direction.

  Next, the moving segments 3a and 4a of the segments 3 and 4 with protrusions are pushed out from the inside of the tunnel with a jack or the like to form protrusions on the upper and lower sides of the lining. And the steel shell 5 is attached to the upper and lower sides of the linings 1 and 2 of the main tunnel T1 and the branch tunnel T2 so as to be bridged between the projections of the moving segments 3a and 4a. Arrange to cover. At this time, as shown in FIG. 3 (b), in order to increase the water-stopping property, the member 5a is attached to the steel shell 5, and the seal member 5b is installed between the member 5a and the segments 3 and 4 with projections. desirable.

  The space between the steel shell 5 and the linings 1 and 2 is filled with a filler 7 made of concrete, and the linings 1 and 2 of the main tunnel T1 and the lamp tunnel T2 are integrated. This integration is performed so that the envelope of the cross section of the lining composed of the main line tunnel T1, the branch line tunnel T2, and the steel shell 5 becomes substantially circular. Then, the support work 6 is removed. As a result, the cross section of the lining portion of the junction TJ between the main tunnel T1 and the lamp tunnel T2 becomes substantially circular, and is mechanically stable. In this way, the lining of the junction TJ between the main tunnel T1 and the ramp tunnel T2 is completed.

In addition, although the cross-sectional shape of the main line tunnel and the branch line tunnel of the present invention is circular, it is not limited to the above-described embodiment, and any cross-sectional shape of the merging portion may be substantially circular, for example, oval Etc.
Further, in the above embodiment, the main road and the ramp of the road tunnel are dug and the junction portion is constructed, but the present invention is also provided when constructing a railway tunnel, a sewer tunnel, etc. having a branching portion and a widening portion. It is possible to apply the construction method of the confluence of shield tunnels.
Needless to say, the specific detailed structure and the like can be changed as appropriate.

It is sectional drawing which shows the construction condition of the junction part of the shield tunnel of one Embodiment to which this invention is applied. It is a cross-sectional detail drawing which shows the extrusion condition of a protrusion-type segment in construction of the junction part of the shield tunnel of one Embodiment to which this invention is applied. It is a perspective view which shows the condition of the lining after a protrusion-type segment is extruded in construction | assembly of the junction part of the shield tunnel of one Embodiment to which this invention is applied.

Explanation of symbols

1, 2 lining 3, 4 segment 5 with projection 5 steel shell 6 support T1 main tunnel T2 branch tunnel TJ junction

Claims (1)

A shield tunnel construction method for constructing a junction between a main tunnel and a branch tunnel respectively constructed by a shield method,
In the section of the merge section, the main tunnel and the branch tunnel are dug so as to be close to each other, and each includes an outer frame segment and a segment with a protrusion that is movably disposed in the upper and lower segments. Assemble an almost circular lining,
Next, a part of the lining that separates the main line tunnel and the branch line tunnel is removed to continue by excavating a natural ground, and a moving segment is pushed out from an outer frame segment of the protruding segment, Protrusions are formed on the upper and lower parts of the tunnel and the branch tunnel, and a steel shell is attached so as to be bridged between these protrusions, and the space between the steel shell and the lining is filled with a filler, and the main tunnel Integrate the lining of the branch tunnel,
A method for constructing a confluence of shield tunnels, characterized in that the envelope of the cross section of the lining consisting of the main tunnel, the branch tunnel and the steel shell is substantially circular.

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