JP2009144425A - Shield method by direct placing concrete lining - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shield method by a direct placing concrete lining which prevents concrete from adhereing to an end frame, suppresses the occurence of trouble when placing the concrete and accordingly achieves the quality improvement of the lining concrete, the improvement of construction speed, and the reduction of construction cost. <P>SOLUTION: In the shield method by the direct placing concrete lining, a new inner form 5a continuous with existing inner forms 5b is assembled into a ring to allow the end form 8 at the inner circumference of a tail part 6 to be slidable thereon inside the tail part 6 of a shield machine, the concrete is placed between the inner form 5 and a natural ground E at the rear of the end frame while propelling the shield machine by reaction force from the inner form 5, and the placing concrete is always pressurized with a predetermined pressure by the end form 8, and further a plurality of concrete placing openings 13 along a tunnel circumferential direction are arranged in the inner form 5 and the concrete is placed through the concrete placing openings 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shield method using direct-cast concrete lining, and more particularly, to a ground lining technique applied as a shield machine is dug in a tunnel method using a shield machine to excavate a tunnel.

  As a lining method in the shield method, a so-called direct concrete lining method (ECL method: Extrude Concrete Lining method) is known in which concrete is cast at the tail portion of a shield machine to construct a lining (lining). According to this construction method, fresh concrete is pressurized and filled in close contact with the ground while propelling the shield machine, so that not only a high-quality lining body can be constructed but also ground subsidence can be suppressed.

  In such a direct-concrete concrete lining method, the lining concrete is placed as follows. That is, the inner mold is assembled inside the tail portion of the shield machine, and concrete is placed between the inner mold and the natural ground while propelling the shield machine by taking the reaction force from the inner mold. On the inner periphery of the tail part of the shield machine, there is provided a ring-shaped wife frame that closes and slides between the inner molds, and a plurality of concrete placement openings are provided along the circumferential direction in the wife frame. . The concrete is sequentially supplied to the placement port via a rotary valve provided in the pipe, and is sequentially placed from each placement port.

  However, in the conventional construction method, since concrete is placed through a placement opening provided in the frame, the concrete adheres to the vicinity of the placement opening, and it grows and closes the placement opening. There's a problem. In addition, there is a problem that the concrete frame is troubled because the wife frame is restrained by the adhering concrete. In addition, the installation port and its piping must be cleaned regularly, but depending on the position of the inner mold placed inside the tail, this may interfere with the cleaning, making cleaning impossible. When appropriate, it can cause concrete placement problems.

As prior art information related to the invention of this application, there is one described in Patent Document 1. However, the technique described in Patent Document 1 separates the adhered concrete from the wife frame by providing a bag body on the wife frame and swells, or scrapes the adhered concrete from the outside of the inner mold frame with a scraping bar. Yes, it does not lead to a fundamental solution.
JP 2002-295193 A

The present invention has been made based on the technical background as described above, and achieves the following object.
The object of the present invention is to prevent the concrete from adhering to the frame and to prevent the occurrence of concrete placing trouble, thereby improving the quality of the lining concrete, improving the construction speed, and reducing the construction cost. It is to provide a shield construction method by direct cast concrete lining.

The present invention employs the following means in order to achieve the above object.
That is, according to the present invention, a new inner mold form continuous with an existing inner mold form is formed in a ring shape so that a wife frame provided on the inner periphery of the tail part can be slidably contacted inside the tail part of the shield machine. While assembling and propelling the shield machine by taking a reaction force from the inner formwork, at the same time, placing concrete between the inner formwork and the ground in the rear of the wifeframe, In the shield method by direct-fired concrete lining that is constantly pressurized at a predetermined pressure by
A direct construction concrete lining shielding method characterized in that a plurality of concrete placement openings are provided in the inner mold frame along the circumferential direction of the tunnel, and concrete is placed through the placement openings.

  More specifically, the shield machine is propelled for each ring length of the inner mold, and at the same time as the one-ring length starts to be propelled, the foremost existing part adjacent to the new inner mold is installed. Concrete is placed from the placement opening of the inner mold. Moreover, concrete is simultaneously placed from the plurality of concrete placement openings. Further, the plurality of concrete placement openings are provided in a plurality of rows in the tunnel axis direction with respect to one ring-shaped inner mold.

  According to the present invention, since the lining concrete is cast from the casting port provided in the inner mold, the problems in the case of casting from the wife frame can be solved at once. That is, the concrete does not adhere to the end frame, the occurrence of a concrete placing trouble can be suppressed, the quality of the lining concrete can be improved, the construction speed can be improved, and the construction cost can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings. First, with reference to FIG. 1 and FIG. 2, the construction procedure of the shield construction method by the direct cast concrete lining to which this invention is applied is demonstrated roughly.

  The shield machine 1 is provided with a partition wall 3 at the front of a main body trunk (skin plate) 2, and a chamber 5 is formed between the partition wall 3 and the cutter 4 for retaining muddy water and mud. In the direct lining method, the inner mold 5 is used for placing lining concrete. This inner mold is formed by assembling a plurality of pieces divided in the circumferential direction into a ring shape. A plurality of propulsion jacks 7 for propelling the shield machine 1 are arranged along the circumferential direction inside the main body body 2, and an inner mold 5 and an inner periphery of the tail section 6 of the main body body 2 are arranged. A ring-shaped wife frame 8 that closes between the tail part 6 and the inner mold frame 5 is arranged to slide. The wife frame 8 is pressed by a plurality of wife frame jacks 9 arranged in the circumferential direction, and the wife frame jack 9 is controlled by a pressure adjusting device 10 connected to an accumulator (not shown) so that the applied pressure is always maintained at a predetermined pressure. Is done.

  Fig.1 (a) has shown the state which completed the assembly of the newly installed inner mold 5a. The new inner mold 5a is assembled inside the tail portion 6 so as to be continuous with the existing inner mold 5b. The shield machine 1 is in a non-propulsion state during the assembly work of the new internal formwork 5a, but the end frame 8 always keeps the lining concrete 11 at the predetermined pressure including the non-propulsion state of the shield machine 1 and the propulsion state described later. Pressurized with.

  After assembling the new inner form 5a, as shown in FIG. 1 (b), the shield machine 1 is propelled to start excavation. The digging length in one process is the length of one ring of the inner mold 5 (the length in the tunnel axis direction). The shield machine 1 is propelled by the operation of the propulsion jack 7, and the reaction force at that time is obtained from the frictional force between the inner mold 5, that is, the inner mold 5 and the lining concrete 11. Then, along with the propulsion of the shield machine 1, fresh concrete is placed between the inner mold 5 and the natural ground E behind the end frame 8. This fresh concrete is pressurized at a predetermined pressure by the end frame 8 as described above. According to the present invention, fresh concrete is placed from a placement opening provided in the inner mold 5, details of which will be described later.

  FIG. 2C shows a state in which the shield machine 1 has finished propulsion for one ring length of the inner mold 5 and has stopped. At this time, the placement of the concrete is also stopped, but during this stop, the end frame 8 pressurizes the placed concrete with a predetermined pressure as described above.

  When the shield machine 1 is stopped, as shown in FIG. 2D, the propulsion jack 7 is contracted to assemble the new inner form 5a. This new internal formwork 5a is a rearrangement of the existing internal formwork 5b at the end. Thereafter, the same procedure as described above is repeated.

  FIG. 3 shows the concrete placement state in detail. As described above, the inner mold 5 is composed of a plurality of (for example, eight divisions) divided pieces, and some of the divided pieces are made of concrete so as to be positioned approximately in the center in the length direction of the inner mold. A placement port 13 is provided. In this embodiment, as schematically shown in FIG. 4, a total of five driving ports are arranged at the tunnel top (port C1) and both sides (ports R2, R3, L2, L3). A placement port 13 is provided in the divided piece corresponding to the port position.

  A concrete pressure feeding pipe 14 is provided for each placement port (see FIG. 4), and each pressure feeding pipe 14 branches into two branch pipes 16 a and 16 b via a two-way switching valve 15. As shown in FIG. 3, one branch pipe 16a is connected to the casting port 13 of the newly installed inner mold 5a, and the other branch pipe 16b is connected to the casting port 13 of the existing inner mold 5b. Has been.

  At the start of the propulsion of the shield machine 1, the end frame 8 is positioned immediately before the placement port 13 of the foremost existing inner form 5b adjacent to the new inner form 5a. At the same time as the shield machine 1 is propelled, concrete placement is started from the placement opening 13 of the existing inner mold 5b at the forefront. This concrete placement is performed simultaneously in the circumferential direction, that is, from the placement ports C1, R2, R3, L2, and L3. When the shield machine 1 is propelled by one ring length of the inner mold 5 and stopped, the wife frame 8 is positioned immediately before the placing port 13 of the new inner mold 5a. At the time of propulsion in the next process, concrete is cast from the casting port 13 of this newly installed inner form 5a (which will be the existing mold at the foremost part in the next process). In FIG. 3, reference numerals 17 and 18 denote packings arranged on the inner and outer peripheries of the end frame 8, and the end frame 8 slides with respect to the inner mold frame 5 and the tail portion 6 through the packings 17 and 18. To do.

  FIG. 5 shows another embodiment. This embodiment is an example in which a plurality of (two) placement ports 13 are provided along the length direction of the divided piece of the inner mold 5 where the placement ports are provided. As a result, the plurality of concrete placement ports 13 along the circumferential direction of the inner mold 5 are provided in two rows in the front-rear direction in the tunnel axis direction. In the case of this embodiment, the concrete placement starts from the front placement opening 13 of the existing mold 5b when the shield machine 1 starts propulsion, and the front placement opening of the existing mold 5b during the promotion of the shield machine 1 The placement position is switched from 13 to the rear placement opening 13 of the new formwork 5a.

  Since the flowability of fresh concrete decreases with the passage of time after placing, it is preferable that the concrete be placed at a position close to the end frame 8. As in the above embodiment, the concrete can be placed at a position close to the wife frame by changing the placement position during the propulsion of the shield machine, that is, while the wife frame 8 is moving. Can be obtained.

  As described above, according to the present invention, since the lining concrete is placed from the placement opening provided in the inner mold, the problems in the case of placing from the wife frame can be solved all at once. That is, the concrete does not adhere to the end frame, the occurrence of a concrete placing trouble can be suppressed, the quality of the lining concrete can be improved, the construction speed can be improved, and the construction cost can be reduced.

It is sectional drawing which shows the construction procedure of the construction method by this invention. It is sectional drawing which shows the construction procedure following FIG. It is sectional drawing which shows the placement state of lining concrete. It is a schematic diagram which shows a placement port. It is sectional drawing which shows another embodiment of an inner formwork.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield machine 2 Main body trunk | body 5 Inner formwork 5a New internal formwork 5b Existing internal formwork 6 Tail part 7 Propulsion jack 8 Wife frame 9 Wife frame jack 10 Pressure adjusting device 13 Placing port 14 Pressure feed pipe 15 Two-way switching valve 16a, 16b Branch pipe

Claims (4)

Assemble the new internal formwork continuous with the existing internal formwork into a ring shape so that the wife frame provided on the inner periphery of the tail part can be slidably contacted inside the tail part of the shield machine. While pushing the reaction machine from the frame and propelling the shield machine, at the same time, the concrete is placed between the inner mold frame and the ground at the rear of the wife frame, and the cast concrete is constantly applied at a predetermined pressure by the wife frame. In the shield construction method by direct hitting concrete lining,
A shield construction method by direct casting concrete lining, wherein a plurality of concrete placement openings are provided in the inner mold frame along the circumferential direction of the tunnel, and concrete is placed through the placement openings.   The shield machine is propelled for each ring length of the inner mold, and at the same time as the propulsion of the one ring length is started, the hitting of the existing inner mold at the frontmost part adjacent to the new inner mold is performed. 2. The shield construction method by direct-casting concrete lining according to claim 1, wherein concrete is cast from the opening.   3. The shield construction method by direct-casting concrete lining according to claim 1, wherein concrete is cast from the plurality of concrete placing ports simultaneously.   The shield method according to claim 1, 2, or 3, wherein the plurality of concrete placement ports are provided in a plurality of rows in the tunnel axis direction with respect to one ring-shaped inner formwork.

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