JP2015090030A - Tunnel lining construction method and management method for tunnel lining concrete placing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tunnel lining construction method and a management method for tunnel lining concrete placing that enable suitable construction of lining concrete, by preventing in an even securer way a cavity from being formed between it and a natural ground.SOLUTION: A tunnel lining construction method and a management method for concrete placing comprise the following: an absorption tube installation step in which an absorption tube 12 is installed in the direction of a tunnel axis O1 at a crown section 1a between a natural ground and a lining concrete mold 9; an air vent/water drain step in which each air vent/water drain material 14 is inserted for installation into each of a plurality of air vent/water drain material insertion holes that have been preformed at the crown part 1a of the lining concrete mold 9, so that the end of the air vent/water drain material 14 comes into contact with the natural ground side, at the same time positioning the lining concrete mold 9 at a prescribed location; a concrete placing step in which concrete 2 is placed between the natural ground and the lining concrete mold 9 while applying pressure; a first air vent/water drain step in which excess air and water are discharged through the air vent/water drain material 14; and a second air vent/water drain step in which excess air and water are discharged through the absorption tube 12 by negative pressure suction.

Description

  The present invention relates to a tunnel lining construction method and a tunnel lining concrete placement management method.

  Before the introduction of the NATM construction method, the sheet pile construction method was used as a construction method for mountain tunnels. In the sheet pile method, excavation of natural ground and installation of steel supporters and wooden sheet piles (sheet piles) along the excavation surface of the natural ground, the sheet pile and lining formwork (centre), the ground pile and lining formwork Put the concrete in between and build the tunnel lining.

  The mountain tunnel constructed by such a sheet pile method is due to the construction method using steel support and wooden sheet piles, especially to construct the arch lining using steel support and wooden sheet piles, A cavity (backside cavity) is formed between the arch and the lining of the top end (crown) and the natural ground. And the side wall part and arch part lower end side of a lining are in contact with the natural ground, and the top end side of the arch part is not in contact with the natural ground by the cavity. For this reason, there is no ground spring around the entire lining, and stress concentration occurs on the top end side of the arch of the lining, in other words, the arching effect of the lining cannot be obtained, and the load carrying capacity of the lining is impaired. Along with this, a crack extending in the tunnel axis direction occurs in the arch portion of the lining. Furthermore, due to the presence of this back cavity, water leakage from cracks, lining joints, gaps between the side wall and arch joints, deterioration / collapse of ground in the cavity, deterioration / peeling of lining concrete, etc. Is triggered.

  On the other hand, a survey of the back cavities of many existing mountain tunnels nationwide, and the back cavities were filled with backfill fillers such as cement-based materials and foamed urethane, and the mountain tunnels constructed by the sheet pile method were used. Measures are being undertaken to prevent or prevent cracks, concrete flaking, deterioration, etc. associated with the back cavity.

  On the other hand, in the mountain tunnel construction method such as the NATM method, the excavation surface is excavated, the excavated surface is covered with spray concrete, rock bolts are placed, and waterproof sheets are installed. ) Is placed and lining concrete is driven in. For this reason, it is considered that cavities are not formed on the back of the lining by properly controlling the placement of the lining concrete, such as compaction by a vibrator, and at least the cavities are inevitably formed as in the conventional sheet pile method. It is not formed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

Japanese Patent No. 4931777 JP 2009-127229 A Japanese Patent No. 4979420

  However, in the mountain tunnel construction method such as the NATM method, as shown in FIG. 6, air or bleeding water (as well as the concrete 2 is launched and compacted on the top end 1 a (arch portion 1 b) of the lining 1. There is a case where the excess air 3 or the excess water 4) accumulates and a cavity 5 is formed even though it is slightly, and there is a possibility that the lining 1 may be cracked due to the cavity 5, There is a risk of leaking water at the edge.

  In view of the above circumstances, the present invention provides a tunnel lining construction method and a tunnel covering capable of preventing the formation of a cavity between the ground and the ground more reliably and appropriately constructing a lining concrete. The purpose is to provide a method for managing concrete placement.

  In order to achieve the above object, the present invention provides the following means.

  The tunnel lining construction method of the present invention is a tunnel lining construction method for constructing a tunnel lining by placing concrete between a ground excavation surface and a lining formwork. A suction tube installation step of installing a suction tube along the tunnel axis direction so as to be arranged at the top end portion between the work mold frames, and arranging the lining mold frame at a predetermined position, and the lining mold frame An air / drainage material installation step in which an air / drainage material is inserted and installed in a plurality of air / drainage material insertion holes formed in advance at the top end so that the tip of the air / drainage material is in contact with the ground mountain side; A concrete placing process in which concrete is pressed between the lining and the lining mold, and the concrete is placed in the concrete placing process, and excess air and surplus water are discharged through the air / drainage material. Cement content through the cutting material When the discharge is confirmed, the air / drainage material is pulled out, and after the first air / drainage process for closing the air / drainage material insertion hole, and after the first air / drainage process, the suction tube is negatively charged. A second air / water draining step of discharging excess air and excess water by pressure suction, filling the filler when the discharge of the excess air and excess water is completed, and closing the inside of the suction tube. It is characterized by that.

  The tunnel lining concrete placement management method according to the present invention is a method for managing the concrete laying of the tunnel lining to construct the tunnel lining by placing concrete between the excavation surface of the natural ground and the lining formwork. The suction tube is installed along the tunnel axis direction so as to be arranged at the top end between the natural ground and the lining formwork, and the lining formwork is arranged at a predetermined position, and the covering Insert the air / water drainage material into the air / water drainage material insertion holes formed in advance at the top end of the work form frame so that the tip is in contact with the natural ground side. Pressurize concrete between the frames and discharge excess air and water through the air / drainage material, and confirm that the cement is discharged through the air / drainage material. Pull out the air / water drain Close the insertion hole, discharge excess air and excess water from the suction tube by negative pressure suction, and confirm that the top end of the lining is filled with concrete by increasing the negative pressure of the suction tube It is characterized by.

  In the tunnel lining construction method and tunnel lining concrete placement management method of the present invention, an air / drainage material insertion hole is formed at the top end of the lining mold, and the air / drainage material is formed. Insert the air / water drainage material into the excavation surface side of the natural ground in the insertion hole and install the air / water drainage material between the lining formwork and the natural ground, and the ceiling between the lining formwork and the natural ground. A suction tube is installed at the end (arch portion), and the lining concrete is driven in a state where the air / drainage material and the suction tube are respectively provided at the top end portion (arch portion) of the tunnel lining.

  The air / water draining material is placed against the waterproof sheet at the top edge, for example, so that excess air or excess water such as air or bleeding water collected at the top edge during the lining of concrete lining is placed. Water is discharged from the air / drainage material insertion hole to the outside of the lining formwork (inside the tunnel lining). In addition, when it is confirmed that a part of the concrete driven in from one direction of the tunnel axis direction (tunnel lining span) is led out from the air / drainage insertion hole and dropped, the air / drainage material Is pulled out and the air / drainage material insertion hole is closed.

  This makes it possible to reliably discharge excess air and excess water such as air at the top end and bleeding water while being driven and filled between the lining formwork and the natural ground while pressing the concrete.

  On the other hand, after closing the air / water draining material insertion hole, surplus air such as air and bleeding water and surplus water are generated due to compaction and pressurization in the concrete driven between the lining formwork and the ground. . On the other hand, in the present invention, the excess air and bleeding water can be discharged, for example, by sucking with negative pressure with a suction tube provided at the top end.

  In other words, the bleeding water of the concrete is generated over time, and if it is not continued to be removed, it will be taken into the concrete and form a weak point in strength. In the final stage of placing, the concrete is pressurized and filled, and excess air, bleeding water, etc. are sucked out with a suction tube, so that it can be discharged securely. At the same time, the top end portion can be filled with concrete densely. In addition, it can be confirmed that the concrete is filled densely when the negative pressure of the suction tube suddenly increases.

  Therefore, according to the tunnel lining construction method and the tunnel lining concrete placement management method of the present invention, by combining the air / drainage material and the suction tube, it is ensured that the lining concrete is placed and after the placement. It is possible to discharge surplus air and surplus water such as air and bleeding water in the generated tunnel arch (top end). As a result, it is possible to prevent a cavity from remaining on the back surface of the lining, and to create a lining that is resistant to cracking and springing, and that has excellent durability, and that has excellent durability. Is possible.

It is a perspective view which shows the condition which builds a lining with the construction method of the tunnel lining which concerns on one Embodiment of this invention. It is sectional drawing which shows the state which installed the sensor for filling compaction detection, and the pressure sensor in the construction method of the tunnel lining which concerns on one Embodiment of this invention. In a tunnel lining construction method and a tunnel lining concrete placement management method according to an embodiment of the present invention, excess air or excess water is removed with an air / drainage material while the lining concrete is placed (pressurized and filled). It is sectional drawing which shows the state which has discharged | emitted. It is sectional drawing which shows the state which has discharged | emitted the excess air and the excess water with the suction tube in the construction method of the tunnel lining which concerns on one Embodiment of this invention, and the concrete placement management method of a tunnel lining. It is sectional drawing which shows the state which inject | poured and filled the filler into the suction tube in the construction method of the tunnel lining which concerns on one Embodiment of this invention, and the concrete placement management method of tunnel lining. It is a figure which shows the condition where surplus air and surplus water accumulate in the top end part (arch part) of a lining, and a cavity is formed.

  Hereinafter, a tunnel lining construction method and a tunnel lining concrete placing management method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5 and FIG. 6.

  First, as shown in FIGS. 1, 2, and 6, the present embodiment relates to a mountain tunnel construction method such as the NATM method, and excavates the natural ground 6 and sprays the excavation surface 6 a (sprayed concrete). 7, after placing a lock bolt and installing the waterproof sheet 8, a lining formwork (centre) 9 is installed and the lining concrete 2 is driven. At this time, for example, the lining mold 9 is installed for each span having a length of about 10 to 12 m in the tunnel axis O1 direction, and the lining concrete 2 is driven to construct the tunnel lining 1.

  In the tunnel lining construction method and the tunnel lining concrete placement management method according to this embodiment, first, as shown in FIGS. 1 and 2, filling compaction is performed on the target span for constructing the lining 1. The detection sensor 10 and the pressure sensor 11 are installed (filling compaction detection sensor installation process, pressure sensor installation process).

  The filling compaction detection sensor 10 detects contact with the concrete 2 that has been struck, and confirms whether or not the concrete 2 is filled in the top end portion 1a. Constructed existing lining side, span center, wife side (wife side of lining formwork 9), and thickness t (thickness between lining formwork 9 and ground 6 (waterproof sheet 8)) ) Is installed on the surface of the waterproof sheet of the top end portion 1a such as a portion that greatly changes by 5 to 10 cm or more.

  The pressure sensor 11 is for confirming the filling state in the space between the lining formwork 9 and the ground 6 of the concrete 2 that has been driven into the space between the lining formwork 9 and the ground 6. Yes, it is installed on the formwork surface of the existing lining side, the span center, and the lining formwork 9 on the wife side.

  Furthermore, in the tunnel lining construction method and tunnel lining concrete placement management method of the present embodiment, as shown in FIG. 1, the top end portion 1a (arch) is formed along the tunnel axis O1 direction and over the entire span length. The suction tube 12 is installed on the natural ground 6 side of the part 1b) (suction tube installation step). In addition, the suction tube 12 has a filtration performance, and is formed so as to be able to suck air and water while preventing intrusion of solids and the like from the surface, for example, formed by weaving a fiber material into a tube shape. Yes. Note that a plurality of suction tubes 12 may be provided not only on the top end portion 1a but also on the arch portion 1b.

  Further, in the tunnel lining construction method and the tunnel lining concrete placement management method of the present embodiment, as shown in FIGS. 1 and 3, the top of the lining formwork 9 (the top end portion 1 a) is previously provided. A plurality of air / drainage material insertion holes 13 are formed at predetermined intervals in the direction of the axis O1. Then, at the stage where the lining formwork 9 is installed at a predetermined position, an air / water draining material (expandable air bleeding tube material) 14 is inserted from each air / water draining material insertion hole 13, and the tip thereof is the waterproof sheet 8 (ground It installs so that it may contact | abut on the excavation surface side of the mountain 6 (air / drainage material installation process). The air / water draining material 14 is formed in a tubular shape, and is provided with an introduction hole and a filter 14a on the distal end side so that surplus air 3 such as air and bleeding water and surplus water 4 can be introduced therein. A plurality of the air / water draining material 14 and thus the air / water draining material insertion holes 13 are provided, and for example, seven (about seven locations) are installed for a tunnel span of 10 to 12 m.

  In the tunnel lining construction method and tunnel lining concrete placement management method of this embodiment, the suction tube 12 and the air / drainage material 14 are arranged at predetermined positions as shown in FIGS. When the lining formwork 9 is installed, the concrete 2 is placed between the lining formwork 9, the ground 6, and the waterproof sheet 8 from the blow-up opening (concrete pouring port) 15 formed in the lining formwork 9. Driving (concrete driving process).

  Moreover, the concrete 2 is driven in from the existing lining side, and the concrete 2 is sequentially filled. At this time, as shown in FIG. 2, since the filling compaction detection sensor 10 and the pressure sensor 11 are provided, the filling state of the concrete 2 between the lining formwork 9 and the ground 6 is measured by each sensor 10, While confirming at 11, the concrete 2 is pressure-filled and the concrete 2 is driven. In addition, it is also possible for an operator to visually confirm the filling state of the concrete 2 through a confirmation window provided in the lining mold 9.

  On the other hand, in this embodiment, as shown in FIG. 1 and FIG. 3, while pressurizing and filling the concrete 2, from the air / drainage material insertion hole 13 at the top (top end 1 a) of the lining mold 9, Excess air 3 and surplus water 4 such as air and bleeding water accumulated in the top end portion 1 a (arch portion 1 b) of the lining 1 are discharged through the air / water draining material 14. Further, the measured values of the filling compaction detection sensor 10 and the pressure sensor 11 are confirmed to confirm that the concrete 2 is filled with a predetermined pressure, and the portion where the cement is discharged through the air / water draining material 14. The air / drainage material 14 is sequentially pulled out from the air / drainage material insertion hole 13 to close the air / drainage material insertion hole 13 (first air / drainage process).

  Next, in this embodiment, as shown in FIGS. 1 and 4, the excess air 3 and the excess water 4 accumulated in the top end portion 1 a of the lining 1 at the air / drainage material insertion hole 13 as described above. After discharging, that is, after the air / water draining material 14 is pulled out, surplus air 3 such as air and bleeding water and surplus water 4 are forcibly discharged using the suction tube 12. Then, as shown in FIG. 5, at the stage where the concrete 2 driving operation is finished and the excess air 3 and the excess water 4 are discharged by the suction tube 12, the filler 16 is injected into the suction tube 12 and closed ( Second air / water draining process).

  Thereby, it becomes possible to construct the lining 1 in a suitable state in which the cavity 5 is not formed in the top end portion 1a (arch portion 1b) of the lining 1.

  Therefore, in the tunnel lining construction method and tunnel lining concrete placement management method of the present embodiment, the air / drainage material insertion hole 13 is formed in the top portion (the top end portion 1a) of the lining mold 9. The air / water draining material 14 is inserted into the air / water draining material insertion hole 13 up to the excavation surface 6 a side of the ground 6 and the air / water draining material 14 is interposed between the lining formwork 9 and the ground 6. In addition, a suction tube 12 is installed at the top end 1a (arch portion 1b) between the lining formwork 9 and the natural ground 6, and the air / water draining material 14 and the suction tube 12 are respectively tunnel-covered. The lining concrete 2 is driven in a state of being provided at the top end portion 1a (arch portion 1b).

  The air / water draining material 14 is placed against the waterproof sheet 8 of the top end 1a, for example, so that air and bleeding water accumulated in the top end 1a during the laying of the lining concrete 2 are provided. The excess air 3 and the excess water 4 are discharged from the air / drainage material insertion hole 13 to the outside of the lining mold 9 (inside the tunnel lining 1). In addition, when it is confirmed that a part of the concrete 2 that has been sequentially driven from one direction of the tunnel axis O1 (the span of the tunnel lining 1) is led out from the air / drainage material insertion hole 13 and dropped, / The water draining material 14 is pulled out, and the air / water draining material insertion hole 13 is closed.

  As a result, it is possible to reliably discharge the air at the top end 1a, bleeding water, and the like while driving and filling between the lining formwork 9 and the natural ground 6 while pressing the concrete 2.

  On the other hand, after the air / water draining material insertion hole 13 is closed, the surplus air 3 such as air or bleeding water is applied to the concrete 2 driven between the lining mold 9 and the ground 6 by compaction or pressurization. Surplus water 4 is generated. On the other hand, in the present embodiment, the excess air 3 and the excess water 4 can be discharged, for example, by sucking with negative pressure with the suction tube 12 provided in the top end portion 1a. Moreover, it can be confirmed that the concrete 2 is filled with solidity when the negative pressure of the suction tube 12 suddenly increases.

  That is, the bleeding water of the concrete 2 is generated with the passage of time and is taken into the concrete 2 to form a weak point in strength if it is not continuously removed. It is buried in the concrete 2 that has been driven into the span overall length), and at the final stage of driving, the concrete 2 is pressurized and filled, and the excess air and bleeding water are sucked out by the suction tube 12 to be surely discharged. And the concrete 2 can be densely filled in the top end portion 1a.

  Therefore, according to the tunnel lining construction method and the tunnel lining concrete placement management method of the present embodiment, by combining the air / water draining material 14 and the suction tube 12, the lining concrete 2 placement is reliably performed. It becomes possible to discharge air, bleeding water, and the like of the tunnel arch portion 1b (top end portion 1a) generated at and after driving. Thereby, it is possible to prevent the cavity 5 from remaining on the back surface of the lining 1, and it is difficult to cause a crack at the top edge of the lining that causes springing or the like, and the lining 1 having excellent durability is suitably used. It becomes possible to build.

  As described above, one embodiment of the tunnel lining construction method and tunnel lining concrete placement management method according to the present invention has been described, but the present invention is not limited to the above-described one embodiment, and departs from the spirit thereof. It is possible to change appropriately within the range not to be.

1 Covering 1a Top end 1b Arch 2 Concrete (lining concrete)
3 Excess air 4 Excess water 5 Cavity 6 Ground 6a Excavation surface 7 Spraying mortar 8 Waterproof sheet 9 Covering form 10 Filling compaction detection sensor 11 Pressure sensor 12 Suction tube 13 Air / drainage material insertion hole 14 Air / Drainage material (expandable air vent tube)
15 Blow-up port (concrete pouring port)
O1 tunnel axis

Claims (2)

A tunnel lining method that constructs a tunnel lining by placing concrete between the excavation surface of the natural ground and the lining formwork,
A suction tube installation step of installing a suction tube along the tunnel axial direction so as to be arranged at the top end between the natural ground and the lining formwork;
The lining mold frame is disposed at a predetermined position, and the tips of the air / drainage materials abut on the natural ground side in a plurality of air / drainage material insertion holes formed in advance at the top end of the lining mold frame. Air / water draining material installation process to insert and install
A concrete placing process in which concrete is pressed between the ground and the lining formwork,
In the concrete placing process, concrete is poured and excess air and / or excess water is discharged through the air / drainage material, and the air / drainage material is pulled out after confirming the discharge of cement through the air / drainage material. A first air / drainage process for closing the air / drainage material insertion hole;
After the first air / water draining process, excess air and / or excess water are discharged from the suction tube by negative pressure suction, and a filling material is filled when the discharge of excess air and / or excess water is completed. A tunnel lining construction method, comprising: a second air / water draining step for closing the water. A method of managing the concrete laying of the tunnel lining, in which concrete is driven between the excavation surface of the natural ground and the lining formwork to construct the lining of the tunnel,
While installing the suction tube along the tunnel axis direction so as to be arranged at the top end between the natural ground and the lining formwork,
The lining mold frame is disposed at a predetermined position, and the tips of the air / drainage materials abut on the natural ground side in a plurality of air / drainage material insertion holes formed in advance at the top end of the lining mold frame. Insert and install as
At the stage of confirming the discharge of the cement through the air / drainage material, pressing the concrete between the natural ground and the lining formwork and driving in, exhausting excess air and excess water through the air / drainage material Pull out the air / drainage material, close the air / drainage material insertion hole,
Exhaust air and excess water are discharged from the suction tube by negative pressure suction, and it is confirmed that the top end portion of the lining is filled with concrete by increasing the negative pressure of the suction tube. How to control the placement of concrete in the factory.

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