JP2012062731A - Jacking method for shield machine, construction method for tunnel entrance section, and tunnel entrance section constructed by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shield machine starting method which dispenses with structure construction work after completion of shield construction, and a construction method for a tunnel entrance section.SOLUTION: A shield machine 4 is installed between a predetermined position of a starting pit mouth 1 and a permanent structure 2 installed near the predetermined position. Subsequently, a permanent segment 7 is installed between the shield machine 4 and the permanent structure 2. The operation of jacking the shield machine 4 by extending a shield jack 5 while taking reaction force of jacking force of the shield machine 4 by the permanent structure 2 via the permanent segment 7 is repeatedly performed.

Description

  The present invention relates to a shield machine propulsion method, a tunnel entrance portion construction method, and a tunnel entrance portion constructed by the method.

  Conventionally, as shown in FIG. 14, when excavating a tunnel with the shield machine 4, the reaction force receiver 14 and the reaction force imparting body 15 for taking the reaction force during the propulsion of the shield machine 4 are placed in the vicinity of the start pit 1. There is known a method of installing and propelling the shield machine 4 while taking a reaction force with the reaction force receiver 14 and the reaction force applying body 15 (for example, Patent Document 1). In this construction method, a temporary segment 16 is installed in the section from the start point 10 of the shield machine 4 to the start pit 1, and a permanent segment 7 is set in the ground 9 from the start pit 1 (see FIG. 15).

  Then, when the tunnel excavation in the natural ground 9 is completed, the reaction force receiver 14 and the temporary segment 16 are removed (see FIG. 16).

  Then, the structure 17 connected with the start pit 1 is formed in the place where the reaction force receiver 14 and the temporary segment 16 were installed, and the tunnel entrance part 18 is constructed | assembled (refer FIG. 17).

JP 2006-16960 A

  However, in the construction method of the tunnel entrance described above, it is necessary to remove the reaction force receiver and the temporary segment after the tunnel excavation, and to construct a structure that is connected to the starting pit. There was a problem that it was.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a shield machine start method and a tunnel entrance part construction method that do not require construction work of a structure after completion of shield construction. It is.

The present invention provides a shield machine propulsion method,
An installation step of installing a shield machine for excavating the tunnel between the planned position of the start pit and the structure existing apart from the planned position;
A starting step of starting the shield machine while taking the reaction force of the propulsion force of the shield machine by the structure;
It is characterized by providing.

In the present invention, after the starting step,
It is provided with a propulsion step of propelling the shield machine while installing a permanent segment between the shield machine and the structure and taking the reaction force of the shield machine with the permanent segment. Also good.

  In the present invention, the end surface of the structure with which the permanent segment abuts may be formed to be flat and perpendicular to the axis of the permanent segment.

  And in this invention, the said structure is good also as providing the flat material in the end surface which the said installation segment contact | abuts.

  Furthermore, in the present invention, the structure may include a reaction force imparting body that is driven into the ground.

  Furthermore, in this invention, it is good also as changing the shape of the edge part of the said structure so that the said installation segment can contact | abut to the said structure.

The present invention relates to a method for constructing a tunnel entrance,
An installation step of installing a shield machine for excavating the tunnel between the planned position of the start pit and the structure existing apart from the planned position;
A starting step of starting the shield machine while taking the reaction force of the propulsion force of the shield machine by the structure;
A propulsion step of propelling the shield machine while installing a permanent segment between the shield machine and the structure, and taking a reaction force of the propulsion force of the shield machine by the permanent segment;
It is characterized by providing.

  Further, the present invention is characterized by being constructed by the above-described tunnel entrance construction method.

  ADVANTAGE OF THE INVENTION According to this invention, the start method of the shield machine and the construction method of a tunnel entrance part which do not need the construction operation | work of a structure after completion of shield construction can be provided.

It is a figure which shows the construction method of the tunnel entrance part which concerns on this embodiment. It is a figure which shows the construction method of the tunnel entrance part which concerns on this embodiment. It is a figure which shows the construction method of the tunnel entrance part which concerns on this embodiment. It is a figure which shows the construction method of the tunnel entrance part which concerns on this embodiment. It is a figure which shows the construction method of the tunnel entrance part which concerns on this embodiment. It is a figure which shows the construction method of the tunnel entrance part which concerns on this embodiment. It is a figure which shows the construction method of the tunnel entrance part which concerns on this embodiment. It is a figure which shows the construction method of the tunnel entrance part which concerns on this embodiment. It is a figure which shows the example of a flat material. It is a figure which shows the example of a flat material. It is a figure which shows the example which provided the steel pipe pile of the reaction force provision body in this installation structure. It is a figure which shows the example which provided the PC anchor of the reaction force provision body in this installation structure. It is a figure which shows the example which provided the wide part in this installation structure. It is a figure which shows the construction method of the conventional tunnel entrance part. It is a figure which shows the construction method of the conventional tunnel entrance part. It is a figure which shows the construction method of the conventional tunnel entrance part. It is a figure which shows the construction method of the conventional tunnel entrance part.

  Hereinafter, a preferred embodiment of a method for constructing a tunnel entrance according to the present invention will be described in detail with reference to the drawings.

  1-8 is a figure which shows the construction method of the tunnel entrance part 18 which concerns on this embodiment.

First, as shown in FIG. 1, a structure construction process for constructing a permanent structure 2 in the vicinity of a planned position of the start pit 1 is performed.
In this step, a main structure 2 such as a building or a tunnel is constructed at a position separated from the planned position of the start pit 1 by a predetermined distance.

  The main structure 2 is used as a reaction force means when the shield machine 4 for excavating the natural ground 9 propels.

  In this embodiment, a circular tunnel in which a vehicle can pass on the roadbed 3 is constructed as the main structure 2, but the present invention is not limited to the tunnel, and the structure / material can be transported to the shield machine 4. It is desirable to have a shape.

  Once the main structure 2 has been constructed, next, the weight of the shield machine 4 at the start is supported on the ground between the planned position of the start well 1 and the main structure 2, as shown in FIG. The ground starting part 6 is constructed.

  Then, the installation process which installs the shield machine 4 on the ground start part 6 is implemented.

  In the present embodiment, a circular shield machine 4 having an outer diameter substantially the same as the outer diameter of the tunnel of the main structure 2 is used as the shield machine 4. As a result, the shield jack 5 of the shield machine 4 can be brought into contact with the side surface 2 a of the tunnel of the main structure 2.

  Next, a start process for starting the shield machine 4 is performed. The starting method of the shield machine 4 will be described below.

  First, as shown in FIG. 3, the permanent segment 7 is installed between the shield jack 5 of the shield machine 4 and the side surface 2 a of the permanent structure 2.

  Next, the shield jack 5 is extended to bring the tip of the shield jack 5 into contact with the permanent segment 7, and subsequently, the permanent segment 7 and the side surface 2 a of the permanent structure 2 are brought into contact with each other.

Then, when the tip of the shield jack 5, the permanent segment 7, and the permanent segment 7 and the side surface 2a of the permanent structure 2 are in close contact, the shield jack 5 is further extended as shown in FIG. The shield machine 4 is propelled leftward in FIG.
At this time, the side surface 2a is flat with respect to the contact surface with the main installation segment 7 so that the extension force of the shield jack 5 acts locally and the main installation segment 7 or the side surface 2a is not destroyed. And it is formed so as to be orthogonal to the axis of the shield jack 5.
The side surface 2a may be formed at the same time as the construction structure 2 is constructed so that the side surface 2a is flat and perpendicular to the axis of the shield jack 5, or the side surface 2a is polished after the construction structure 2 is constructed. May be formed.

  When the shield jack 5 is extended to a predetermined stroke, the shield jack 5 is contracted as shown in FIG. 5, and thereafter, a new one is provided between the shield jack 5 and the existing permanent segment 7 as shown in FIG. The main installation segment 7 is installed.

Next, the shield jack 5 is extended to bring the new permanent segment 7, the permanent segment 7 and the side surface 2a of the permanent structure 2 into close contact with each other, and then the shield jack 5 is extended to shield the shield machine. 4 is promoted.
In this way, the shield machine 4 is propelled by repeating the expansion and contraction of the shield jack 5 and the installation of a new permanent installation segment 7.

  As shown in FIG. 7, when the tip of the shield machine 4 reaches the planned construction position of the start pit 1, the shield machine 4 is propelled while the cutter head 8 is rotated to excavate the natural ground 9.

  And the start pit 1 is constructed | assembled by installing the segment 7 for main installation also in the location which excavated the natural ground 9. FIG.

  Even after the starting pit 1 is constructed, the above-described series of operations are repeated while excavating the natural ground 9 to construct the tunnel entrance 18 as shown in FIG.

  According to the construction method of the tunnel entrance portion 18 in the present embodiment described above, the installation work and removal of the temporary reaction force receiver that has been conventionally performed by using the existing main structure 2 as the reaction force means. Work can be saved.

  In addition, by installing the permanent segment 7 from the starting point 10 of the shield machine 4 through the starting pit 1 in the natural ground 9, it is possible to eliminate the removal work of the temporary segment that has been conventionally installed. it can. And the period of tunnel construction can be shortened in addition to being able to omit the installation work and removal work of the reaction force receiver mentioned above.

  In addition, since the permanent segment 7 installed in the natural ground 9 from the starting point 10 of the shield machine 4 via the starting pit 1 is used as a structure as it is, when the reaction force receiver and the temporary segment are removed conventionally In addition, it is possible to prevent the opening between the main segments 7 in the vicinity of the start pit 1.

  Further, since the side surface 2a of the permanent structure 2 is formed flat, the permanent segment 7 can be evenly adhered. As a result, when the shield jack 5 is extended, the eccentric thrust of the shield jack 5 does not act on the permanent segment 7 and the side surface 2a of the permanent structure 2, so that the permanent segment 7 and the permanent Breakage of the side surface 2a of the structure 2 can be prevented. Further, since the side surface 2a is formed so as to be orthogonal to the axis of the shield jack 5, the thrust of the shield jack 5 is not decentered by this, so that the permanent segment 7 and the permanent structure 2 Damage to the side surface 2a can be prevented.

  In addition, although this embodiment demonstrated the case where the side surface 2a of this installation structure 2 was formed flat, it is not limited to this, When the unevenness | corrugation exists in the side surface 2a, it is flat on the side surface 2a. The material 11 may be attached. In such a case, as shown in FIGS. 9 and 10, the flat member 11 is attached at a position where the shield jack 5 abuts. Thereby, the segment 7 for installation can be made to closely_contact | adhere, and damage to the side 2a of the segment 7 for installation and the installation structure 2 can be prevented, without making the thrust of the shield jack 5 eccentric. . The flat member 11 may be flat and rigid, and for example, steel plate or plate-like concrete can be used.

  If the propulsion force of the shield machine 4 is large and the weight of the main structure 2 is not sufficient as a reaction force means, the reaction force imparting body 12 is installed from the main structure 2 into the ground. Thus, it may be a part of the reaction force means. As the reaction force imparting body 12, a well-known steel pipe pile 12a (see FIG. 11), a PHC pile, a PC anchor 12b (see FIG. 12), or the like can be used. However, it shall have the intensity | strength which can take the reaction force at the time of the propulsion of the shield machine 4. Moreover, also about the placement method of the reaction force application body 12, the well-known placement method according to the kind of reaction force application body 12 to be used can be applied.

  In addition, in this embodiment, although the case where the shape of the shield machine 4 and this installation structure 2 was made circular was demonstrated, it is not limited to this shape, A rectangular shape may be sufficient.

  In the present embodiment, the case where the outer diameter of the shield machine 4 and the outer diameter of the tunnel of the permanent structure 2 are substantially the same has been described. However, the outer diameter of the permanent structure 2 is larger than the outer dimension of the shield machine 4. When the size is small and part of the permanent installation segment 7 cannot contact the side surface 2a of the permanent installation structure 2, as shown in FIG. 13, the widened portion for contacting the permanent installation segment 7 13 may be provided. Since the widened portion 13 also has a function as the reaction force imparting body 12, when the widened portion 13 is provided, the reaction force imparting body 12 described above may not be provided. Whether or not to provide the body 12 is appropriately determined by design or the like.

  Moreover, in this embodiment, although the case where the circular thing was used as the segment 7 for permanent installation installed from the permanent structure 2 to the starting pit 1 was not limited to this shape, A rectangular shape, U-shape, U-shape, or the like may be used.

  Furthermore, in this embodiment, although the case where the starting point 10 of the shield machine 4 was provided on the ground with the top opened was not limited to this, the existing tunnel in the ground was extended. It is also possible to apply it. In this case, a cavity for installing the shield machine 4 is provided on the side of the existing tunnel, and the shield machine 4 is started from the cavity.

DESCRIPTION OF SYMBOLS 1 Start pit 2 Main structure 2a Side surface 3 Subbase 4 Shield machine 5 Shield jack 6 Ground start part 7 Segment 8 Cutter head 9 Ground 10 Start point 11 Flat material 12 Reaction force grant body 12a Steel pipe pile 12b PC anchor 13 Widening part 14 Reaction force receiver 15 Reaction force giving body 16 Temporary segment 17 Structure 18 Tunnel entrance part

Claims (8)

In the propulsion method of the shield machine,
An installation step of installing a shield machine for excavating the tunnel between the planned position of the start pit and the structure existing apart from the planned position;
A starting step of starting the shield machine while taking the reaction force of the propulsion force of the shield machine by the structure;
A propulsion method for a shield machine, comprising: After the start process,
Providing a propulsion step of propelling the shield machine while installing a permanent segment between the shield machine and the structure and taking a reaction force of the propulsion force of the shield machine by the permanent segment. The propulsion method for a shield machine according to claim 1, wherein   3. The shield according to claim 1, wherein an end surface of the structure with which the permanent segment abuts is formed so as to be flat and perpendicular to the axis of the permanent segment. How to propel the machine.   The method for propelling a shield machine according to claim 1, wherein the structure includes a flat member on an end surface with which the permanent segment abuts.   The method for propelling a shield machine according to any one of claims 1 to 4, wherein the structure includes a reaction force imparting body placed in the ground.   The shield according to any one of claims 1 to 5, wherein a shape of an end portion of the structure is deformed so that the main installation segment can come into contact with the structure. How to propel the machine. In the construction method of the tunnel entrance,
An installation step of installing a shield machine for excavating the tunnel between the planned position of the start pit and the structure existing apart from the planned position;
A starting step of starting the shield machine while taking the reaction force of the propulsion force of the shield machine by the structure;
A propulsion step of propelling the shield machine while installing a permanent segment between the shield machine and the structure, and taking a reaction force of the propulsion force of the shield machine by the permanent segment;
A method for constructing a tunnel entrance, characterized by comprising:   A tunnel entrance portion constructed by the tunnel entrance portion construction method according to claim 7.

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