JP2020105863A - Natural ground draining device - Google Patents

Abstract

To provide a natural ground draining device capable of efficiently draining water from a natural ground to the inside of a covering body by maintaining a non-return valve in the open state.SOLUTION: A natural ground draining device 60, which drains the ground water of a natural ground through an open hole formed on a covering body installed on the natural ground to the inside of the covering body, has a non-return valve 40 disposed in the open hole penetrating the covering body from its inner surface to outer surface, and non-return valve open-state maintaining means 60A, which maintains the non-return valve 40 in the open state so that the ground water of the natural ground passes through the non-return valve and is drained to the inside of the covering body.SELECTED DRAWING: Figure 1

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groundwater draining device for draining groundwater from a ground to the inside of a lining body by using a check valve installed in a through hole of a lining body installed in the ground.

The grouting hole (injection hole) of the annular lining body (segment ring), which is excavated by the shield machine and installed in the tunnel cavity formed behind the shield machine, is used to A method is known in which groundwater from the ground is drained to the inside of the annular lining body (see Patent Document 1).
The said method is through a grout hole (injection hole) in the tail void which is the gap between the inner peripheral surface of the tunnel cavity formed in the rear of the shield machine and the outer peripheral surface of the lining body, which is formed behind the shield machine. After filling the backing material such as mortar, install a drainage device at the mouth of the grout hole equipped with a check valve, and drill the backing material filled in the grout hole and in the tail void using a boring machine. This is a method in which a through hole reaching the natural ground is formed, and a water pipe is inserted into the through hole to drain groundwater in the natural ground around the lining body to the inside of the lining body.

Japanese Patent No. 5282541

In the above-mentioned prior art, a check pipe having rotatable valve elements on both left and right sides of the valve element support is provided by passing a water pipe through a through hole formed by boring a backfill material filled in the grout hole and the tail void. Only one valve body of the valve is pushed open by the water pipe, and water is drained by the water pipe. That is, a through hole having a diameter smaller than the check valve passage diameter is formed, and a water passage having a diameter smaller than the check valve passage diameter is inserted into the through hole, and a through hole is formed through the water passage pipe. Since groundwater is drained to the inside of the lining body, it takes time to drain water and it is not possible to drain water efficiently.
The present invention provides a water removal device for natural rocks, which allows water to be efficiently drained from the natural rocks to the inside of the lining body by maintaining the check valve in an open state.

The groundwater draining device according to the present invention is a groundwater draining device for draining groundwater of the ground into the inside of the lining body through a through hole formed in the lining body installed in the ground. And the check valve provided in the through hole that penetrates through the inner surface and the outer surface of the lining body, and groundwater in the ground passes through the check valve and is drained to the inside of the lining body. As described above, since the check valve opening maintaining means for maintaining the check valve in the open state is provided, by maintaining the check valve in the open state, water can be efficiently drained from the ground to the inside of the lining body. Like
Also, since the lining body is a segment ring installed in the tunnel cavity formed behind the shield machine as the shield machine excavates, it was installed in the tunnel cavity formed by the shield method. Draining work for draining groundwater around the segment ring to the inside of the segment ring can be performed easily.
Further, the check valve is provided with a plurality of valve bodies, and the check valve opening maintaining means is configured to maintain the plurality of valve bodies in an open state.
Further, the check valve includes a cylindrical portion that functions as an attachment portion to the through hole, and a valve portion, the valve portion includes a valve body portion and a valve seat, and the valve body portion includes a valve body, And a valve body support portion, the valve body portion is constituted by a circular body having a diameter corresponding to the inner diameter of the cylindrical portion, the circular body connecting the opposite points of both ends of the diameter of the inner circumference of the cylindrical portion. The central portion constitutes the valve body support portion, and the semicircular plate portions provided on both left and right sides of the valve body support portion constitute the valve body, and the boundary portion between the valve body support portion and the valve body is interposed. The valve seat is configured to be rotatable, and the valve seat projects from the inner peripheral surface of the cylindrical portion toward the center line of the cylindrical portion and contacts the surface of the arc edge of the valve body close to the inner surface of the lining body. The check valve opening maintaining means, which is formed by an annular wall surface, includes a check valve opening member, a relay member, a pressing member for pressing the check valve opening member, and a check valve opening maintaining member with a water outlet. The check valve opening member includes a bifurcated tip portion having left and right claws that are inserted into the through hole from the inner surface side of the lining body to push open the left and right valve bodies of the check valve, and a rear end of the bifurcated tip portion. The relay member is configured by a cylindrical member, and the cylindrical member includes a screw member of the check valve open maintaining member on the peripheral surface on the one end face side in the direction along the center line. The screw part is provided with a threaded part, and the peripheral surface on the other end face side in the direction along the center line is provided with a male threaded part screwed into the female threaded part of the through hole. A non-return valve opening member is provided with an inlet into which the shaft portion is inserted, and one end of the sheath pipe portion is closed, and the one end portion of the sheath pipe portion is provided so as to be separated from each other in a direction orthogonal to the central axis of the sheath pipe portion. The check valve opening maintaining member is screwed to the thread portion of the relay member so that both ends of the horizontal shaft portion of the pressing member are pressed against one end surface of the relay member. As a result, the check valve is maintained in an open state, and groundwater in the ground passes through the check valve and the water outlet of the check valve open maintenance member to drain water inside the lining body. The feature is configured as described below.
Since the water draining device is provided with the check valve and the check valve opening maintaining means as described above, it is possible to efficiently drain water from the natural ground to the inside of the lining body through all the flow paths of the check valve. Become.
Further, the check valve opening maintaining member is characterized by being constituted by a three-way switching valve having three inlets and outlets, so that the draining work and the check valve clogging release work can be easily performed.

The disassembled perspective view which shows the water removal apparatus attached to a through-hole. Sectional drawing which shows the state in which the check valve opening member was attached to the injection hole. Sectional drawing which shows the state in which the check valve opening member and the relay member were attached to the injection hole. Sectional drawing which shows the state in which the check valve opening member, the relay member, and the pressing member were attached to the injection hole. Sectional drawing which shows the state which the check valve opening maintenance means was attached to the injection hole, and the water draining device was comprised. The process drawing explaining the division by the shield construction method. Sectional drawing which shows the shield machine used for the shield construction method. Sectional drawing which shows the through-hole formed in the segment. Sectional drawing which shows the state in which the check valve was attached to the through-hole of a segment. FIG. 3 is an exploded perspective view showing a support device attached to a through hole. Sectional drawing which shows the state with which the cylindrical member was attached to the through-hole. Sectional drawing which shows the state with which the support device was attached to the through-hole. The perspective view which shows the example of arrangement|positioning of the support apparatus and the drainage apparatus with respect to a tunnel lining body. (A) is a perspective view of a screw pipe member, (b) is a longitudinal cross-section of the screw pipe member (Embodiment 2).

Embodiment 1
As shown in FIGS. 1, 6 and 13, the groundwater draining device 60 according to the first embodiment, which is used for draining the ground in the shield construction method, causes the shield machine 1 to move as the shield machine 1 advances. A check valve 40 provided in a through hole 23 that penetrates through an inner surface and an outer surface of a segment 20 that constitutes a segment ring 30 as an annular lining body installed in a tunnel cavity formed in the rear, And a check valve opening maintaining means 60A for maintaining the check valve 40 in an open state so that groundwater in the ground passes through the check valve 40 and is drained to the inside of the segment ring 30.

As shown in FIG. 8, each segment 20, 20... As a lining member that constitutes the segment ring 30 penetrates through the inner surface 21 and the outer surface 22 of the segment 20 in the substantially central portion of the arc-shaped plate surface. A through hole 23 with an internal thread is formed.
The through hole 23 has a configuration in which a female screw portion 25 is provided on the inner peripheral surface of a through hole 24 that penetrates the inner surface 21 and the outer surface 22 of the segment 20. The female screw portion 25 is provided on the center side in the direction along the center line of the through hole 24. Specifically, the female screw portion 25 is, for example, a trapezoidal screw.
In the following description, the female screw portion 25 and the screw portion other than the female screw portion screwed to the female screw portion 25 are triangular screws, for example.
The female threaded portion 25 is formed, for example, from one end opening 26a of the hollow tube 26 to the center of the hollow tube 26 on the inner circumferential surface of the hollow tube 26 made of casting which is buried in the inner circumferential surface side of the through hole 24 of the segment 20. It is formed by a female screw portion 25 extending over the side.
The outer peripheral surface of the hollow tube 26 is provided with an annular fixing portion 27 protruding from the periphery of the outer peripheral surface of the hollow tube 26 in order to secure the fixing of the segment 20 to the concrete.

For example, the hollow tube 26 described above is fixed to a reinforcing bar arranged in a mold (not shown) for manufacturing the segment 20, and one end of the hollow tube 26 is formed to form the hollow portion of the through hole 24. After arranging an unillustrated core that closes the opening 26a and an unillustrated core that closes the other end opening 26b of the hollow tube 26, fresh concrete was placed in the formwork, and then the concrete hardened. After that, by pulling out the core, a through hole 23 with a female screw portion 25 penetrating over the inner surface 21 and the outer surface 22 of the segment 20 as shown in FIG. 8 is formed at approximately the center of the plate surface of the segment 20. The formed segment 20 is manufactured.

By mounting the check valve 40 on the female screw portion 25 of the through hole 23, the injection hole 28 as shown in FIGS. 1 and 9 is formed.

As shown in FIG. 9, the check valve 40 is configured to include, for example, a cylindrical portion 41 and a valve portion 42 provided inside the cylindrical portion 41.
On the outer peripheral surface of the cylindrical portion 41, a male screw portion 43 screwed to the female screw portion 25 of the through hole 23 is provided. The male screw portion 43 functions as a mounting portion of the through hole 23 to the female screw portion 25.
The valve portion 42 is configured to include a valve body portion 44 and a valve seat 45.
The valve body portion 44 includes a valve body 46 and a valve body support portion 47.
For example, the valve body portion 44 is configured by a circular body having a diameter corresponding to the inner diameter of the cylindrical portion 41.
The central portion of the circular body that connects the opposite points (positions on the inner circumferential surface of the cylindrical portion 41 that are 180 degrees apart from each other in the circumferential direction) at the two ends of the diameter of the inner circumferential circle of the cylindrical portion 41 is the valve body support portion 47. And the semicircular plate portions provided on both the left and right sides of the valve body support portion 47 constitute the valve bodies 46, 46. That is, the central portion of the circular body forming the valve body support portion 47 extends, for example, along a diameter line passing through the center of the circular body, and both extended ends are both ends of the diameter of the inner circumference circle of the cylindrical portion 41. It is composed of a plate-like body having a rectangular cross section fixed to the opposite point of.
A straight line portion serving as a boundary between the valve body support portion 47 and the valve bodies 46, 46, that is, a central portion of a circular body forming the valve body support portion 47 and each semicircle of a disc body forming the valve bodies 46, 46. The chord portion that is a boundary with the plate member is formed in the hinges 48 and 48 that are the rotation centers of the valve bodies 46 and 46.
The valve seat 45 is a surface that comes into contact with the surface of the arc edges 49 of the valve bodies 46, 46 in the flow path closed state on the side closer to the inner surface 21 of the segment 20, that is, from the inner peripheral surface of the cylindrical portion 41 to the cylindrical portion 41. It is formed by an annular wall surface projecting toward the center line.

In the check valve 40, the male screw portion 43 of the cylindrical portion 41 is screwed to the female screw portion 25 of the through hole 23 and attached to the through hole 23, and the valve bodies 46, 46 rotate toward the outer surface 22 side of the segment 20. As a result, the inside of the cylindrical portion 41 is in a channel open state in which it communicates as a channel. That is, a flow path is formed between the valve body support portion 47 and the valve seat 45. In the valve open state, the object can flow from the inner surface 21 side of the segment 20 toward the outer surface 22 side through the flow path. In addition, a flow path closed state in which the surfaces of the arc edges 49, 49 of the valve bodies 46, 46 on the side closer to the inner surface 21 of the segment 20 come into contact with the valve seat 45 to close the flow path inside the cylindrical portion 41. In, the flow of the object from the outer surface 22 side of the segment 20 to the inner surface 21 side is closed.
That is, the check valve 40 allows movement of the object from the inner surface 21 side of the segment 20 toward the outer surface 22 side, and does not allow movement of the object from the outer surface 22 side of the segment 20 toward the inner surface 21 side. Has become.
That is, when the backing material is injected from the inner surface 21 side of the segment 20 to the outer surface 22 side of the segment 20 through the injection hole 28 and filled, a surface close to the inner surface 21 of the segment 20 at the arc edge 49 of the valve body 46. The respective valve bodies 46, 46 rotate so that they are separated from the valve seat 45, and the inside of the cylindrical portion 41 communicates with each other as a flow path to open the flow path, so that the tail void can be filled with the backing material.
Further, the valve bodies 46, 46 and the valve seat 45 come into contact with each other due to the pressure of the fluid such as the backfill material and the groundwater that have flowed into the injection hole 28 from the outer surface 22 side of the segment 20, so that the flow passage inside the cylindrical portion 41 is formed. Will be closed.

That is, in the check valve 40, the valve bodies 46, 46 and the valve seat 45 are brought into contact with each other by the pressure of the fluid such as the backfill material and groundwater that have flowed into the injection hole 28 from the outer surface 22 side of the segment 20, and the cylindrical portion 41. In order to drain groundwater from the outer surface 22 side of the segment 20 to the inner surface 21 side of the segment 20 via the flow path of the check valve 40, the inner flow path of the segment 20 is closed. It is necessary to maintain the left and right valve bodies 46, 46 of the check valve 40 in the open state. Therefore, in the drainage device 60, the check valve 40 is maintained in the open state by using the check valve opening maintaining means 60A, so that groundwater in the ground flows from the outer surface 22 side of the segment 20 to the check valve 40. The water is passed through the passage to the inside of the segment ring 30.

As shown in FIG. 1, the check valve opening maintaining means 60A includes a check valve opening member 61, a relay member 62, a pressing member 63 for pressing the check valve opening member 61, and a check valve opening with water outlet. The maintenance member 64 is provided.

As shown in FIGS. 1 and 2, the check valve opening member 61 is a left and right claw that is inserted into the injection hole 28 from the inner surface 21 side of the segment 20 to push open the left and right valve bodies 46, 46 of the check valve 40. A bifurcated tip portion 66 including the portions 65, 65 and a shaft portion 67 extending rearward from the left and right central portions 66e at the rear end of the bifurcated tip portion 66 are provided.

The bifurcated tip portion 66 is formed in a plate shape, and as shown in FIG. 2, the widthwise dimension 66W of the bifurcated tip portion 66 is slightly smaller than the inner diameter dimension of the cylindrical portion 41 of the check valve 40. Is formed.
In the left and right claws 65, 65, the edge surfaces 68, 68 facing each other form a V-shaped surface, and the lower end of the V-shaped surface, which is the boundary portion between the left and right claws 65, 65, is reversed. It is formed in the concave groove portion 69 into which the valve body support portion 47 of the stop valve 40 is inserted.
The bifurcated tip portion 66 is formed in a shape in which a pentagonal plate material such as a home base is partially cut away. For example, a triangular region for forming a V-shaped surface is cut out from one side edge of a pentagon such as a home base which has an angle of 90° with adjacent sides of both sides, and the cut triangular region is formed. The left and right sides are formed as left and right claw portions 65, 65.

As shown in FIGS. 1 and 3, the relay member 62 is composed of a cylindrical member. The cylindrical member that constitutes the relay member 62 is a male screw to which a female screw portion 85 of a check valve open maintaining member 64 with a water outlet, which will be described later, is screwed onto the outer peripheral surface of the one end opening 62a side in the direction along the center line of the cylindrical member. In addition to the portion 70, a male screw portion 71 screwed to the female screw portion 25 of the hollow tube 26 is provided on the outer peripheral surface on the other end opening 62b side in the direction along the center line of the cylindrical member.

As shown in FIGS. 1 and 4, the pressing member 63 includes a sheath tube portion (sleeve) 75 having an inlet at the tip end side into which the shaft portion 67 of the check valve opening member 61 is inserted and having one end closed. It is formed in a T-shape having left and right horizontal shaft portions 76 provided so as to be separated from one end of the sheath tube portion 75 in a direction orthogonal to the center line of the sheath tube portion 75.

As shown in FIG. 1 and FIG. 5, the check valve open maintaining member 64 with a water outlet is constituted by, for example, a three-way switching valve having three inlets/outlets (ports) 80, 81, 82.
For example, the three-way switching valve that constitutes the check valve opening maintaining member 64 with the water outlet has the first inlet/outlet 80 formed by the one end opening of the cylindrical portion 83 and the second one formed by the other end opening of the cylindrical portion 83. A structure provided with, for example, a ball valve (not shown) for switching a flow path inside a trifurcated tube having an inlet/outlet port 81 and a third inlet/outlet port 82 formed by a side opening provided on a side portion of the cylindrical portion 83. What is necessary is just to use.
That is, the check valve opening maintaining member 64 with a water outlet is, for example, a first inlet/outlet 80 and a second inlet/outlet 81 facing each other, and a straight line passing through the center of the first inlet/outlet 80 and the center of the second inlet/outlet 81. A three-way switching valve having a third inlet/outlet port 82 that opens in the direction.
In addition, the ball valve is provided with an operating shaft 84 that projects to the outside of the cylindrical portion 83 to operate the ball valve, and a jig such as a wrench is engaged with the operating shaft 84 to rotate the operating shaft 84. It is configured to be operable.
On the inner peripheral surface of each of the entrances/outlets 80, 81, 82, a female screw portion 85 configured to be screwed onto the male screw portion 70 of the relay member 62 described above is formed.

A method of mounting the check valve open maintaining means 60A will be described.
First, as shown in FIG. 2, the forked tip portion 66 of the check valve opening member 61 is inserted into the injection hole 28 from the inner surface 21 side of the segment 20, and the left and right claw portions 65, 65 of the forked tip portion 66 are reversed. The check valve opening member 61 is set so that the valve bodies 46, 46 of the stop valve 40 are pushed open toward the outer surface 22 side of the segment 20.
Next, as shown in FIG. 3, the male screw portion 71 of the relay member 62 is screwed and attached to the female screw portion 25 of the hollow tube 26.
As shown in FIG. 4, with the shaft portion 67 of the check valve opening member 61 inserted into the sheath tube portion 75 of the pressing member 63, the pressing member 63 is set in a state of being pressed against the check valve 40 side.
Then, as shown in FIG. 5, for example, the female screw portion 85 of the check valve opening maintaining member 64 with a water outlet is screwed to the male screw portion 70 of the relay member 62 to form the female screw portion 85, for example. So that the bottom surface 86 of the screw hole presses both end portions 77, 77 of the horizontal shaft portion 76 of the pressing member 63 to press the end portions 77, 77 against the one end surface 62e of the relay member 62. The check valve opening maintaining member 64 with a water outlet is attached to the relay member 62.
As described above, the check valve opening maintaining means 60A for maintaining the check valve 40 of the injection hole 28 in the flow path opened state is attached to the injection hole 28, and the drainage device 60 is configured.
That is, the drainage device 60 allows the groundwater in the ground to pass through the check valve 40 and the third inlet/outlet 82, which is the water outlet of the check valve opening maintaining member 64, to be drained to the inside of the lining body. Is composed of.

The three-way switching valve as the check valve opening maintaining member 64 with a water outlet can operate a ball valve to connect the first inlet/outlet 80 and the third inlet/outlet 82 to close the second inlet/outlet 81, for example. The first inlet/outlet 80, the second inlet/outlet 81, and the third inlet/outlet 82 can be communicated with each other, or a ball valve is operated to connect the first inlet/outlet 80 and the third inlet/outlet 82. The second inlet/outlet 81 can be closed by connecting the first inlet/outlet 80 and the second inlet/outlet 81 to each other and the third inlet/outlet 82 can be closed.

In the case of using the drainage device 60 to pass groundwater from the ground outside the segment ring 30 to the inside of the segment ring 30, connect one end of a drain hose (not shown) to the third inlet/outlet 82, By operating the valve, for example, the first inlet/outlet 80 and the third inlet/outlet 82 provided at mutually orthogonal positions are communicated with each other to close the second inlet/outlet 81, whereby groundwater from the natural ground is drained by the drainage device 60 and drained. For example, the water is drained to a drainage tank installed in the starting shaft 100 via the hose, and then drained to the ground from the drainage tank by a pump or the like.
When the tunnel to be constructed has an upward slope, groundwater is allowed to flow down from the third entrance/exit 82 to the inside of the segment ring 30 without connecting a drain hose to the third entrance/exit 82 to be installed in the starting shaft 100. It can be drained to the ground by a pump or the like.

Moreover, when the flow path of the check valve 40 is blocked with earth and sand, the second inlet/outlet port 81 is opened, and a rod or the like is inserted from the second inlet/outlet 81 to close the flow path of the check valve 40. Etc. can be removed and clogging of the flow path can be eliminated.

According to the drainage device 60 according to the first embodiment, both the left and right valve bodies 46, 46 of the check valve 40 can be maintained in the open state, so that the check valve 40 is covered from the ground through the entire flow path. It will be possible to drain water efficiently inside the structure.
Further, according to the water drainage device 60 according to the first embodiment, the check valve opening maintaining member 64 is configured by the three-way switching valve having the three inlets/outlets 80, 81, 82, so that the flow path of the check valve 40 is When it is blocked with earth and sand, for example, the second inlet/outlet 81 can be opened, and a rod or the like can be inserted from the second inlet/outlet 81 to remove the earth/sand or the like blocking the flow path of the check valve 40. The water draining device 60 can easily perform the water draining operation and the check valve 40 clogging release operation.

Hereinafter, an example of the shield construction method using the water draining device 60 will be described.
This shield method judges whether the water pressure of groundwater in the ground of the face is higher than the standard, and if the water pressure of groundwater in the ground of the face is below the standard, the normal shield is used. When construction (hereinafter referred to as normal construction) is performed and it is determined that the groundwater pressure in the ground at the face of the face is higher than the standard, shield construction is performed while draining the ground (hereinafter referred to as specific construction). To do.

As shown in FIG. 6, when it is determined that the groundwater pressure in the ground of the face part is higher than the standard, the face construction is performed in the segment ring installation section Y (see FIG. 6C). When the water pressure of groundwater in the ground is judged to be higher than the standard, the inner and outer peripheral surfaces of the segment rings 30, 30... As a plurality of annular linings installed in the tunnel cavity Draining work is performed to drain groundwater in the ground into the insides of the plurality of segment rings 30, 30... Through the through holes penetrating therethrough.
Then, as a result of the water draining work, when it is determined that the water pressure of the ground at the face of the cutting face has dropped to the reference level or less, the outer peripheral surfaces of the plurality of segment rings 30, 30... The back voiding material filling operation of filling the back void material into the tail void, which is a gap between the ground and the ground, is performed to complete the shield tunnel in the segment ring installation section Y.

In the shield construction method, as shown in FIG. 6(a), the shield machine 1 is started from the starting shaft 100, and, for example, as shown in FIG. 6(b), the water pressure of groundwater in the ground of the cutting face is the standard. In the segment ring installation section X when it is determined that it is the following, the normal construction is performed and the shield excavator 1 excavates the ground to form a segment in the tunnel cavity formed behind the shield excavator 1. It is assumed that, for example, several to several tens of rings 30 are installed.
After that, for example, it is assumed that when a discharge gate 10e of the screw conveyor 10 of the shield machine 1 which will be described later is opened, a jet is generated, and it is determined that the water pressure of groundwater in the ground of the face of the face is higher than the reference.
In this case, as shown in FIG. 6(c), the segment ring installation section Y, which is the period after the segment ring installation section X until it is determined that the water pressure of the ground of the cutting face has dropped to a state below the reference A plurality of segment rings 30, 30... Are installed in the above, and drainage work is performed to drain groundwater in the ground into the plurality of segment rings 30, 30.
Then, as a result of the water draining work, when it is determined that the water pressure in the ground at the face of the face has dropped below the reference, the outer peripheral surfaces of the plurality of segment rings 30, 30... The back void material is filled in the tail void that is a gap between the shield ring and the segment ring installation section Y to complete the shield tunnel.
Then, when it is determined that the water pressure of the groundwater in the ground of the face portion is below the reference, as shown in FIG. 6C, the segments 30, 30... Are sequentially installed on the front side in the excavation direction of the segment ring installation section Y. In the segment ring installation section X after the construction of the segment ring installation section Y, which will be performed, normal work is performed.

That is, in the shield construction method, in the segment ring installation section X, which was constructed by determining that the water pressure of groundwater in the ground at the face of the face was below the standard, the tunnel cavity formed along with the excavation of the shield machine 1 Immediately after the segment ring 30 is installed in the section, normal construction is performed to fill the tail void, which is the gap between the outer peripheral surface of the segment ring 30 and the natural ground, with a backfill material such as mortar, and Complete the shield tunnel.
Then, in the segment ring installation section Y, which was constructed by determining that the water pressure of groundwater in the ground of the face portion is higher than the reference, the segment ring 30 is formed in the tunnel cavity formed by the excavation of the shield machine 1. Immediately after the installation of the shield ring machine 1 without the backfill material filling work of filling the back void material into the tail void that is the gap between the outer peripheral surface of the segment ring 30 and the ground, In addition, drainage work is performed in which groundwater in the natural ground is passed through the plurality of segment rings 30, 30... Through the through holes formed in the plurality of segment rings 30, 30.
Then, as a result of the water draining work, when it is determined that the water pressure of the ground at the face of the face has dropped to the level below the reference, the outer peripheral surfaces of the plurality of segment rings 30, 30... Installed in the segment ring installation section Y. Perform backfill material filling work that fills the backfill material together in the tail void that is the gap between the ground and the ground. That is, the shield tunnel in the segment ring installation section Y is completed by sequentially performing the backfill material filling operation from the segment ring 30 on the rear side (starting shaft 100 side) in the segment ring installation section Y.

Next, a configuration example of the shield machine 1 used in the shield construction method will be described.
As shown in FIG. 7, the shield machine 1 includes a cutter head 2 at the front end in the direction of excavation, and an outer shell 3 behind the cutter head 2. A partition wall 4 is provided on the front side of the outer shell 3, and a chamber 5 is provided between the partition wall 4 and the cutter head 2.
Inside the outer shell 3, devices such as an erector 6, a shield jack 7, a center folding jack 8, a cutter head drive device 9, and a screw conveyor 10 are provided.

The cutter head 2 is, for example, a disk-shaped member for excavating a face, and a cutting member such as a plurality of bits 2a is mounted on the front surface of the cutter head 2. The cutter head 2 is configured to be rotatable forward and backward along the circumferential direction of the outer shell 3 in front of the outer shell 3.

The outer shell (skin plate) 3 includes, for example, a front body plate 3a and a rear body plate 3b connected to the rear end side of the front body plate 3a.
The front body plate 3a and the rear body plate 3b are formed of, for example, a cylindrical steel plate.
The inside of the rear body plate 3b is configured into a tail portion 11 equipped with an erector 6, a tail seal 3c, and the like, and the segment ring 30 is assembled by the erector 6 at the tail portion 11.
The tail seal 3c is a sealing member for preventing groundwater and the like from entering into the outer shell 3 from the ground behind the rear body plate 3b during excavation work, for example, the rear end portion of the rear body plate 3b. Further, it is installed in a frame shape along the outer periphery of the rear body plate 3b.

The chamber 5 is a space filled with excavated earth and sand between the cutter head 2 and the partition wall 4.
That is, in the shield machine 1, the earth and sand excavated by the cutter head 2 is taken into the chamber 5 through an opening (not shown) of the cutter head 2 and the chamber 5 is excavated in a state of being filled with mud. It is a mud pressure shield machine that excavates when mud pressure is generated and the mud pressure opposes the earth pressure of the face.

The erector 6 grips a segment (segment piece) 20 as a lining member and turns, and arranges a plurality of segments 20, 20... along the inner peripheral surface of the tail portion 11 to assemble the segment ring 30. Is.

The segment 20 is a lining member made of, for example, reinforced concrete that covers the inner peripheral surface of the tunnel cavity formed by the excavation of the shield machine 1.
A plurality of segments 20, 20,... Forming one segment ring 30 are conveyed to the tail portion 11, and the segment ring 30 is assembled in the tail portion 11 by the erector 6.
That is, the segment ring 30 is configured by combining a plurality of segments 20 formed in the shape of an arc block that constitutes the annular peripheral wall of the segment ring 30.

As shown in FIG. 3, a through hole 23 having a female screw portion 25 penetrating over the inner surface 21 and the outer surface 22 of the segment 20 is formed at approximately the center of the arc-shaped plate surface of each segment 20, 20. Has been done.

The shield jack 7 uses the segment ring 30 assembled in the tail portion 11 and the segment ring 30 installed in the tunnel cavity behind the shield machine 1 as a reaction force to propel the shield machine 1 forward. It is a jack that generates force.
A plurality of shield jacks 7 are arranged side by side in the outer shell 3 along the circumferential direction of the outer shell 3, at positions that straddle the boundary between the front body plate 3a and the rear body plate 3b.

The center folding jack 8 is a jack for connecting the front body plate 3a and the rear body plate 3b and correcting the propulsion direction of the shield machine 1. A plurality of the center folding jacks 8 are arranged in a line along the circumferential direction of the outer shell 3 at positions that straddle the boundary between the front body plate 3a and the rear body plate 3b in the outer shell 3.
By supplying pressure oil to the center folding jack 8 and propelling the shield machine 1 in a state where the front body plate 3a and the rear body plate 3b are refracted in a predetermined direction and angle, the shield machine 1 It is possible to control the propulsion direction of.

The cutter head drive device 9 is a motor (drive source) that rotates the cutter head 2 in forward and reverse directions. A plurality of cutter head drive devices 9 are arranged side by side along the circumferential direction of the cutter head 2, for example, on the back surface side of the cutter head 2.

The screw conveyor 10 is a device for discharging the earth and sand taken into the chamber 5 to the rear of the shield machine 1.
The screw conveyor 10 is a sealed conveyor that conveys earth and sand by a screw auger 10b arranged inside the cylinder 10a, and the earth and sand intake opening 10c provided at one end of the cylinder 10a is arranged inside the chamber 5, A sediment discharge port 10d provided at the other end of the cylinder 10a is provided so as to be located behind the shield machine 1. The sediment discharge port 10d is provided with a discharge gate 10e that opens and closes the sediment discharge port 10d.
The excavated earth and sand taken into the chamber 5 is conveyed from the earth and sand intake opening 10c to the earth and sand discharge port 10d by the screw auger 10b, and the excavated earth and sand is discharged from the earth and sand discharge port 10d by opening the discharge gate 10e. A belt conveyor (not shown), a carrier, etc., conveys it into the starting shaft 100 and discharges it to the ground.

When it is determined that the water pressure of groundwater in the ground of the face of the face is below the reference, the normal construction using the shield machine 1 described above is performed as follows.
A plurality of segments 20, 20... Are arranged along the inner peripheral surface of the tail portion 11 of the outer shell 3 of the shield machine 1 by the erector 6 of the shield machine 1 and along the inner peripheral surface of the tail portion 11. The segment rings 30 are assembled by connecting the ends of the adjacent segments 20, 20 with each other using a connecting tool.
Then, the rear ends of the pistons of the plurality of shield jacks 7, 7... Arranged at a plurality of positions at predetermined intervals along the inner peripheral surface of the outer shell 3 of the shield machine 1 are assembled in the tail portion 11. The thrust is applied to the shield machine 1 and the cutter head 2 is driven by the propulsive reaction force obtained by extending the pistons of the shield jacks 7, 7... From the state of being pressed against the front end face of the segment ring 30. The shield machine 1 is excavated by excavating the face. Then, after the shield machine 1 is excavated, the tail void, which is a gap between the outer peripheral surface of the segment ring 30 installed in the tunnel cavity formed in the rear of the shield machine 1 and the natural ground, is filled with the backfill material. Then, the lining by the segment ring 30 is completed.
Then, the pistons of the shield jacks 7, 7,... Are retracted to assemble the new segment ring 30 on the tail portion 11 located in front of the previously formed segment ring 30, and after the segment ring 30 assembled this time. The end portion and the front end portion of the previously assembled segment ring are connected using a connecting tool.
That is, in the normal construction, by repeating a series of operations of assembling the segment ring 30 in the tail portion 11 →digging work of the shield machine 1 →filling the tail void with backfill material, the rear of the shield machine 1 is repeated. And a cylindrical tunnel cover formed by a plurality of segment rings 30, which are installed along the inner peripheral surface of the tunnel cavity and are connected to each other adjacent to the front and rear. A work body is formed.

When the shield machine 1 is started from the starting shaft 100, the reaction jacks (not shown) of the shield jacks 7, 7... Are installed in the starting shaft 100 to install the shield jack 7 of the shield machine 1. , 7... The rear end of the piston is pressed against the reaction force receiver, and the propulsive reaction force obtained by extending the piston of the shield jack 7, 7... By driving the cutter head 2 to excavate the face, the shield machine 1 is started.

In the specific work when it is determined that the water pressure of groundwater in the ground of the face is higher than the reference, a series of work of assembling the segment ring 30→water countermeasure work→digging work is repeatedly performed.
The water countermeasure work is a lifting prevention work of the segment ring 30 installed in the tunnel cavity, and a drainage work into the segment ring 30 installed in the tunnel cavity.

Then, if it is determined that the water pressure of the natural ground at the face of the face has decreased due to the specific construction and has fallen below the standard, the plurality of segment rings 30, 30 installed in the segment ring installation section Y during the specific construction The back voiding material filling work is performed to fill the tail voids, which are the gaps between the outer peripheral surface and the ground, with the back voiding material, and then shift to normal construction.

The water countermeasure work will be explained.
For example, the check valve 40 is not attached to the through hole 23 of the segment 20 to be located above the segment ring 30 assembled in the tail portion 11, and the support device 50 as shown in FIG. Mounted.
Further, in the injection hole 28 formed by attaching the check valve 40 to the through hole 23 of the segment 20, as described above, the check valve opening maintaining means 60A that constitutes the drainage device 60 together with the check valve 40. Is installed.

As shown in FIG. 10, the supporting device 50 used for the lifting prevention work of the segment ring 30 installed in the tunnel cavity portion is, for example, an advancing/retreating member provided with a male screw portion 51 formed on the entire outer peripheral surface. The configuration includes a screw member 52 and a cylindrical member 53 that guides the screw member 52 forward and backward.
The cylindrical member 53 includes a male screw portion 54 formed on the outer peripheral surface on the one end opening 53a side in the direction along the center line and screwed to the female screw portion 25 of the through hole 23, and is formed on the entire inner peripheral surface. This is a configuration including a female screw portion 55 to which the male screw portion 51 of the screw member 52 is screwed.
First, as shown in FIG. 11, the cylindrical member 53 is attached to the through hole 23 by screwing the male screw portion 54 of the cylindrical member 53 onto the female screw portion 25 of the through hole 23 and fastening and fixing. The cylindrical member 53 is attached to the through hole 23 so that the other end opening 53b is located on the outer surface 22 side of the segment 20.
Then, as shown in FIG. 12, the male screw portion 51 of the screw member 52 is screwed into the female screw portion 55 of the cylindrical member 53, so that the tip 52 t of the screw member 52 projects outward from the outer surface 22 of the segment 20. The support device 50 is provided so as to be capable of advancing and retreating between the open state and the state located in the through hole 23.
The one end surface 52a of the screw member 52 is provided with a jig engaging portion 52b for engaging a jig such as a nut driver or a screwdriver to rotate the screw member 52 around the center line as a rotation center.

The procedure for lifting prevention work is as follows.
For example, in the starting shaft 100, the cylindrical member 53 is previously attached to the through hole 23 of the segment 20 to which the supporting device 50 is attached, the segment 20 is conveyed to the tail portion 11, and the segment is formed at the tail portion 11. After the ring 30 is assembled, the screw member 52 is attached to the cylindrical member 53. Then, after the segment ring 30 is installed in the tunnel cavity from the rear end of the outer shell 3 of the shield machine 1, the screw member 52 is operated (turned) to move the tip 52t of the screw member 52 to the segment 20. The segment ring 30 is supported by the ground by projecting outward from the outer surface 22 and abutting the ground.
According to the supporting device 50, since the screw member 52 is only rotated to project the tip 52t of the screw member 52 to the outside of the outer surface 22 of the segment 20, the working time can be shortened, the work is simple, and the cost is low. A method of supporting the segment ring 30 and a supporting device 50 can be provided.
The support device 50 is attached to the through hole 23 of the segment 20 arranged above the plurality of segment rings 30, 30... Installed in the segment ring installation section Y, as shown in FIG. 13, for example. For example, the support devices 50 are arranged in a staggered manner along the extension direction of the plurality of segment rings 30, 30... Installed in the segment ring installation section Y.
In this case, as shown in FIG. 13, the support device 50 is provided in the through holes 23 of the segments 20 arranged above all the plurality of segment rings 30, 30... Installed in the segment ring installation section Y. Alternatively, among the plurality of segment rings 30, 30,... Installed in the segment ring installation section Y, the support device 50 is provided only in the through hole 23 of the segment 20 arranged above the arbitrary segment ring 30. May be provided.

The procedure for draining work is as follows.
After the segment ring 30 is installed in the tunnel cavity from the rear end of the outer shell 3 of the shield machine 1, the check valve open maintaining means 60A is attached to the injection hole 28 of the segment ring 30 to form the water draining device 60.
The check valve opening maintaining means 60A is attached to all of the injection holes 28 of the plurality of segment rings 30, 30... Installed in the segment ring installation section Y or to the selected injection holes 28, A plurality of drainage devices 60 are provided on the plurality of segment rings 30, 30...
Also, when the check valve opening maintaining means 60A is attached to the injection hole 28, groundwater flows down inside the segment ring 30. At this time, when the tunnel is an uphill slope, the groundwater flowing down inside the segment ring 30 flows to the starting shaft 100. Therefore, after collecting the groundwater in the drainage tank installed in the starting shaft 100, the pump, etc. It should be drained from the drain tank to the ground. Further, when the tunnel is not an uphill slope, the groundwater flowing down inside the segment ring 30 may be drained to the starting shaft 100 using a pump or the like.

In the specific construction, the water of the natural rock invades the tail void between the outer peripheral surface of the plurality of segment rings 30, 30... Installed in the segment ring installation section Y and the natural rock (the inner wall of the tunnel cavity portion). , The plurality of segment rings 30 installed in the segment ring installation section Y are supported by the support devices 5, 5... While preventing the floating of the 30, 30,..., The groundwater that has entered the tail voids is guided by the drainage devices 60, 60... Inside the plurality of segment rings 30, 30... Installed in the segment ring installation section Y. As it is drained, the water pressure of the groundwater at the ground of the face can be reduced.

As a result of the water draining work, when it is determined that the water pressure in the ground at the face of the face has dropped below the standard, the check valve opening maintaining means 60A of the water draining device 60 is removed from the injection hole 28, and the segment ring installation section Y is installed. The back void material is filled in the tail voids between the outer peripheral surfaces of the plurality of installed segment rings 30, 30... And the ground through the check valves 40, 40.
After that, shift to normal construction.

The support device 50 may remain attached to the through hole 23, or the support device 50 may be removed from the through hole 23 and the check valve 40 may be attached to the through hole 23.
Further, finally, the opening on the inner surface side of the segment ring 30 of the through hole 23 of the segment rings 30, 30,... Is closed by attaching a cap (not shown).

According to the shield construction method, when the water pressure of groundwater in the ground of the face is higher than the standard, a plurality of segment rings 30, 30... Are installed in the tunnel cavity along with the excavation of the shield machine 1, and The support device 50 is attached to the plurality of through holes 23, 23 penetrating the inner and outer surfaces of the segment rings 30, 30 to prevent the plurality of segment rings 30, 30... Check valve open maintaining means 60A is attached to a plurality of injection holes 28, 28 (through holes in which the check valve 40 is attached to the through hole 23) penetrating through the inner and outer surfaces of the segment rings 30, 30. The drainage device 60 is configured to drain the groundwater from the ground inside the plurality of segment rings 30, 30..., and the water pressure of the groundwater in the ground at the face portion is below the reference level. In this case, the backing material filling operation is performed to fill the backing material in the gaps between the outer peripheral surfaces of the plurality of segment rings 30, 30... And the ground.
That is, after it is determined that the water pressure of groundwater in the ground of the face portion is higher than the reference, each drainage device 60 attached to the plurality of through holes 23, 23... Of the segment ring 30 installed in the tunnel cavity. Each time a new segment ring 30 is installed in the tunnel cavity after the water draining operation is started by the water drainage work 60, the water drainage devices 60, 60 attached to the plurality of through holes 23, 23... Of the new segment ring 30. Since the drainage work is performed by ..., after it is determined that the groundwater pressure in the ground at the face of the face is higher than the standard, it is determined that the environment of the ground at the face of the face is under high water pressure, and then the face of the face is cut. Until it is judged that the water pressure of groundwater in the ground has decreased to below the standard, a plurality of through holes 23, 23 with a plurality of segment rings 30:30... Since the water draining operation is continuously performed by the water drainage devices 60, 60 attached to the ..., when the water pressure of the groundwater in the ground of the face part is higher than the standard, the water pressure of the groundwater in the ground of the face part is high. Can be lowered.
Further, as shown in FIG. 13, for example, the support device 50 is attached to the through holes 23 of the segment 20 arranged above the plurality of segment rings 30, 30... Installed in the segment ring installation section Y. At the time of draining work, groundwater flows between the outer peripheral surfaces of the plurality of segment rings 30:30 installed in the tunnel cavity and the ground, and buoyancy is applied to the plurality of segment rings 30, 30. Even if so, since the plurality of segment rings 30:30... Are supported by the support devices 50, 50... on the natural ground, it is possible to prevent the plurality of segment rings 30, 30. It has become possible to reduce the amount of deviation between the designed installation position of 30... and the actual installation position.
Then, after it is determined that the water pressure of the groundwater in the ground at the face of the face has dropped below the reference level, the outer peripheral surfaces of the plurality of segment rings 30, 30... Since the backfilling material filling work of collectively filling the backfilling material in the tail voids between the plurality of segment rings 30:30... Installed in the segment ring installation section Y can be stably supported by the ground. ..

Further, in the above-mentioned Patent Document 1, every time the shield machine excavates, the back void material is filled into the tail void, the drainage device is attached, the hole material is drilled, the drainage operation is performed again Since it is necessary to perform a lot of work such as filling work, there is a problem that the construction period becomes long. In particular, every time the shield machine excavates, the filling work of the backfill material into the tail void, the work of drilling the backfill material, and the filling work of filling the tail void material with the backfill material again are inefficient. Is.
On the other hand, in the shield construction method, when the water pressure of groundwater in the ground of the face is higher than the standard, the through hole 23 of the segment ring 30 installed in the tunnel cavity is formed every time the shield machine 1 excavates. When the lifting prevention work and drainage work are performed and the water pressure of the groundwater in the ground at the face of the face falls below the standard, the plurality of segment rings 30, 30 installed in the segment ring installation section Y by then... Since the back voiding material filling work into the tail voids is performed collectively, the work is simplified and the shield tunnel can be smoothly constructed when the groundwater pressure in the ground of the face is higher than the standard.

Further, the lifting prevention work of the annular lining body is performed on the through holes 23 other than the through holes 23 used for the water draining work among the through holes 23 penetrating over the inner surface and the outer surface of the plurality of segment rings 30, 30... By mounting the screw member 52 as an advancing/retreating member provided so as to be capable of advancing and retracting in a state in which the tip 52t projects outward from the outer peripheral surface of the segment ring 30 and a state in which the tip 52t is positioned in the through hole 23, The tip end 52t of the screw member 52 is projected outward from the outer peripheral surface of the segment ring 30 and abutted against the ground to support the plurality of segment rings 30, 30... Of the segment rings 30, 30... can be prevented from rising, and the amount of deviation between the designed installation position and the actual installation position of the plurality of segment rings 30, 30. You can do it.

The draining work is performed by attaching check valve opening maintaining means 60A that maintains the check valve 40 installed in the through hole 23 in the open state to the through hole 23, and the backfill material filling work is performed by the check valve. After removing the opening maintaining means 60A from the through hole 23, the back filling material filling device (not shown) was connected to the through hole 23 (injection hole 28) with the check valve 40, so that the draining work was smoothly performed. Not only can this be done, but the transition from draining work to backfill material filling work can be done easily, so the shield tunnel can be installed smoothly.

Further, according to the supporting device 50 used in the shield construction method, the trapezoidal screw for mounting the check valve is formed on the central side in the extending direction of the through hole 23 penetrating the inner surface 21 and the outer surface 22 of the segment 20. A cylindrical member 53 having an internally threaded portion 25 configured and an externally threaded portion 54 screwed to the internally threaded portion 25 and having an internally threaded portion 55 on the inner peripheral surface, and a female threaded portion 55 of the cylindrical member 53. Since the tip end 52t is attached to the outer surface of the segment 20 and the tip end 52t is positioned in the through hole 23, the screw member 52 as an advancing/retreating member is provided. After attaching the support device 50 to the through hole 23 of the segment ring 30 and installing the segment ring 30 from the rear end of the outer shell 3 of the shield machine 1 into the tunnel cavity, the tip 52t of the screw member 52 is attached to the segment 20. The segment ring 30 can be supported on the ground by projecting outward from the outer surface 22 and hitting the ground, and the segment rings 30, 30... Can be prevented from rising.

According to the water drainage device 60 used in the shield construction method, the inner and outer surfaces of the segment ring 30 installed in the tunnel cavity formed behind the shield machine 1 along with the excavation of the shield machine 1 are extended. A non-return valve 40 attached to the penetrating through-hole 23, and the non-return valve 40 is maintained in an open state so that groundwater in the ground passes through the non-return valve 40 and is drained to the inside of the segment ring 30. Check valve opening maintaining means 60A configured as described above.
The check valve 40 includes a cylindrical portion 41 that functions as a mounting portion for the through hole 23, and a valve portion 42. The valve portion 42 includes a valve body portion 44 and a valve seat 45. The body portion 44 includes left and right valve bodies 46, 46 and a valve body supporting portion 47, and the valve bodies 46, 46 are rotatable via a boundary portion between the valve body supporting portion 47 and the valve bodies 46, 46. The valve seat 45 is formed by an annular wall surface projecting from the inner peripheral surface of the cylindrical portion 41 toward the center line of the cylindrical portion 41.
The check valve opening maintaining means 60A includes a check valve opening member 61, a relay member 62, a pressing member 63 that presses the check valve opening member 61, and a check valve opening maintaining member 64 with a water outlet.
The check valve opening member 61 is a forked tip portion including left and right claw portions 65, 65 that are inserted into the injection hole from the inner surface 21 side of the segment ring 30 and push open the left and right valve bodies 46, 46 of the check valve 40. 66, and a shaft portion 67 extending rearward from a central portion 66e at the rear end of the forked tip portion 66.
The relay member 62 includes a male screw portion 70 to which a screw portion of the screw member of the check valve opening/maintenance member with a water outlet is screwed on the outer peripheral surface on the side of the one end opening 62a in the direction along the central axis. A cylindrical member is provided on the outer peripheral surface on the side of the other end opening 62b in the direction along which a male screw portion 71 screwed to a female screw portion such as a trapezoidal screw is formed.
The pressing member 63 has an inlet into which the shaft portion of the check valve opening member 61 is inserted at the distal end side, and has a sheath pipe portion 75 whose one end is closed, and a center of the sheath pipe portion 75 from one end of the sheath pipe portion 75. It is formed in a T shape with left and right horizontal shaft portions 76 provided so as to be separated from each other in a direction orthogonal to the axis.
Then, for example, a three-way switching valve that constitutes the check valve opening maintaining member 64 with a water outlet is screwed to the male screw portion 70 of the relay member 62, and both ends of the horizontal shaft portion of the pressing member 63 are connected to one end of the relay member 62. The check valve is maintained in an open state by being attached so as to be pressed against the opening 62a, so that groundwater in the natural ground can check the check valve and the water outlet of the check valve opening maintaining member 64. It was configured to pass through and drain inside the segment ring.
By using the water draining device 60, it is possible to easily perform the water draining work of draining the groundwater flowing between the outer peripheral surface of the segment ring 30 installed in the tunnel cavity and the ground into the inside of the segment ring 30. Became.

According to the water draining device 60 used in the shield construction method, the check valve opening maintaining member 64 with the water outlet is constituted by the three-way switching valve having the three inlets/outlets (ports) 80, 81, 82. A female screw portion 85 of 80 is screwed to the male screw portion 70 of the relay member 62, a three-way switching valve is attached to the relay member 62, and the first inlet/outlet 80 and the third inlet/outlet 82 provided at positions orthogonal to each other are communicated with each other. Then, by closing the second inlet/outlet 81, the drainage work of draining the groundwater flowing between the outer peripheral surface of the segment ring 30 and the ground into the inside of the segment ring 30 via the drainage device 60 can be easily performed. When the flow path of the check valve 40 is clogged with earth and sand, the second inlet/outlet port 81 is opened and a rod or the like is inserted from the second inlet/outlet port 81 to block the flow path of the check valve 40. Since the soil and the like that are present can be removed, the drainage device 60 can easily perform the drainage work and the clogging release work of the check valve 40.

Embodiment 2
Instead of the screw member 52, a screw tube member 520 as shown in FIG. 14 may be used.
The screw tube member 520 includes a screw tube 510 formed of, for example, synthetic resin or iron, and a lid 530.
The threaded tube 510 includes a male threaded portion 511 formed on the entire outer peripheral surface and a through hole 522 formed on the outer peripheral surface on the other end opening 521 side and penetrating the inner surface and the outer surface of the tube. One or more through holes 522 are formed.
The lid 530 has a female screw portion 531 formed on the inner peripheral surface thereof so that the male screw portion 511 on the one end opening 523 side of the screw pipe 510 can be screwed into the one end opening so that the one end opening 523 of the screw pipe 510 can be opened and closed. It is formed by a circular cylindrical lid with a bottom at one end that is detachably configured so as to close 523.

The other end opening 521 side of the screw tube member 520 is inserted into the through hole 23 from the opening of the through hole 23 on the segment inner surface 21 side, and the male screw portion 511 of the screw tube 510 is screwed to the female screw portion 55 of the cylindrical member 53 to be screwed. The other end opening 521 side of the pipe 510 is projected outward from the outer surface of the segment ring 30 and abuts against the natural ground, whereby the segment ring 30 is supported by the natural ground. After that, the lid 530 is removed, the one end opening 523 is opened, and a drain hose or the like is connected to the one end opening 523, whereby groundwater from the natural ground passes through the through hole 522, the inside of the screw pipe 510, the one end opening 523, and the drainage. It is drained inside the segment ring 30 via a hose or the like.

By using the screw tube member 520 instead of the screw member 52, it is possible to perform both lifting prevention work and drainage work.

Further, the threaded pipe member 520 is attached to all the through holes 23 of the plurality of segment rings 30, 30... Installed in the segment ring installation section Y to perform both lifting prevention work and drainage work, After it is determined that the water pressure in the natural ground at the face of the face has dropped to below the reference level, the screw pipe member 520 is removed from the through hole 23, and the check valve 40 is attached to the through hole 23 from which the screw pipe member 520 has been removed. The outer voids of the plurality of segment rings 30, 30... Installed in the segment ring installation section Y may be filled with the backing material.

Further, by forming a through hole in the segment 20 having a threaded member 52 as an advancing/retreating member and a female threaded portion to which a male threaded portion formed on the outer peripheral surface of the threaded tube member 520 can be screwed, the threaded member 52 and the screw member are screwed. Instead of using the cylindrical member 53 for guiding the advance/retreat of the pipe member 520, a supporting device configured to directly screw the screw member 52 or the screw pipe member 520 into the female screw portion of the through hole of the segment 20 may be used. ..

In addition, a trapezoidal screw as the female screw portion 25 provided on the center side in the direction along the center line of the through hole 24, and a screw member or a screw tube member that is directly screwed to the trapezoidal screw and configured to be capable of advancing and retreating. A configured support device may be used.

The conditions such as the water pressure condition of the ground of the face part and the number of the segment rings 30 installed in the segment ring installation section Y, for example, the water pressure of the ground of the face part is slightly higher than the standard In the case where the number of the segment rings 30 installed in the installation section Y is small, etc., when it is determined that the work of preventing the lifting of the plurality of segment rings 30, 30... Installed in the segment ring installation section Y is unnecessary, After performing the draining work without performing the lifting prevention work of the plurality of segment rings 30, 30 installed in the segment ring installation section Y, and determining that the water pressure of the ground of the face part has fallen below the standard, The tail voids between the outer peripheral surfaces of the plurality of segment rings 30, 30... Installed in the segment ring installation section Y and the natural ground may be filled with the backfill material.
That is, when the water pressure of groundwater in the ground at the face of the face is higher than the reference, a plurality of segment rings 30, 30... Are installed in the tunnel cavity along with the excavation of the shield machine 1, and the plurality of segment rings 30, By using a plurality of through holes 23 penetrating the inner surface and the outer surface of 30... and draining groundwater in the ground inside the plurality of segment rings 30, 30,... When the water pressure of groundwater in a part of the ground is below the standard, backfill material filling work is performed to fill the backfill material in the gaps between the outer peripheral surfaces of the plurality of segment rings 30, 30... And the ground. It may be performed.

Whether or not the water pressure of groundwater in the ground at the face of the face is higher than the reference is determined by, for example, a soil pressure gauge (not shown) provided in the partition wall 4 for measuring the soil pressure in the chamber 5. It is judged whether or not the pressure value is higher than the reference design earth pressure value (for example, 0.3 MPa).
That is, the earth pressure value in the chamber 5 which is measured by the earth pressure gauge during the excavation work of the shield machine 1 and displayed on the display means of the driver's seat (not shown) is observed, and the earth pressure value is lower than the design earth pressure value. In the case where the soil pressure value in the chamber 5 becomes lower than the design earth pressure value, the drainage operation is performed without performing the backfill material filling operation in the segment ring installation section Y, The segment ring installation section by performing the backing material filling operation of filling the back void material in the tail void that is the gap between the outer peripheral surface of the plurality of segment rings 30, 30... Complete the shield tunnel at Y.
Specifically, when the earth pressure value in the chamber 5 is high, the segment required for the earth pressure value in the chamber 5 to become lower than the design earth pressure value due to the difference between the earth pressure value and the design earth pressure value. The length of the ring installation section Y is predicted, and the soil in the chamber 5 is finished at the time when the construction (construction without draining material and without backfill material filling work) in the segment ring installation section Y having the predicted length is completed. Check the pressure value, and if the earth pressure value at that time is higher than the design earth pressure value, extend the length of the segment ring installation section Y so that the earth pressure value at that time is lower than the design earth pressure value. For example, by performing the backing material filling operation of filling the back void material into the tail void that is the gap between the outer peripheral surface of the plurality of segment rings 30, 30... The shield tunnel in the segment ring installation section Y may be completed.

Further, although the example in which the segment 20 made of reinforced concrete is used is shown as the lining member, a segment made of steel other than reinforced concrete, a segment made of ductile cast iron, a segment made of a composite structure of concrete and steel, etc. is used. I don't mind.

Further, the lining body to which the water draining device 60 of the present invention is attached may be any lining body that is installed in the ground, and is a lining body other than the segment ring which is the annular lining body in the shield construction method described above. May be
For example, it may be an annular lining body that constitutes the wall of the shaft, or a U-shaped lining body that is used for the down approach section and the up approach section when constructing a tunnel that underpasses the road. A non-return valve provided in a through hole that penetrates the inner and outer surfaces of the lining body and a non-return valve so that groundwater in the ground passes through the check valve and is drained inside the lining body. A drainage device with check valve opening maintaining means for maintaining the valve in an open state is configured, and by maintaining the check valve in an open state, water is efficiently drained from the ground to the inside of the lining body. become able to.

Further, as the check valve opening maintaining means 60A of the water draining device, the one configured to maintain the plurality of valve bodies 46 of the check valve 40 in the open state has been illustrated, but as the check valve opening maintaining means, May have any structure as long as it is a means for maintaining the valve body in an open state corresponding to the structure of the valve body of the check valve.

1 shield machine, 23 through holes, 30 segment ring (lining body),
40 check valve, 41 cylindrical portion, 42 valve portion, 44 valve body portion, 45 valve seat, 46 valve body,
47 valve body support part, 60 drainage device, 60A check valve opening maintaining means,
61 check valve opening member, 62 relay member, 63 pressing member, 64 check valve opening maintaining member,
65 claw (nail), 66 bifurcated tip, 67 shaft, 75 sheath tube, 76 horizontal shaft,
80, 81, 82 gateway (port), 82 third gateway (water outlet).

Claims (5)

A groundwater draining device for draining groundwater of the ground into the inside of the lining body through a through hole formed in the lining body installed in the ground,
A check valve provided in a through hole penetrating over the inner surface and the outer surface of the lining body,
A check valve opening maintaining means for maintaining the check valve in an open state so that groundwater in the ground passes through the check valve and is drained to the inside of the lining body;
It is equipped with a water drainage device for natural ground. The water drainage device according to claim 1, wherein the lining body is a segment ring installed in a tunnel cavity formed behind the shield machine as the shield machine advances. The check valve includes a plurality of valve bodies,
The non-return valve open-maintaining means is configured to maintain a plurality of valve bodies in an open state, and the drainage device for the natural ground according to claim 1 or 2. The check valve includes a cylindrical portion that functions as a mounting portion to the through hole, and a valve portion,
The valve portion includes a valve body portion and a valve seat,
The valve body portion includes a valve body and a valve body support portion,
The valve body portion is composed of a circular body having a diameter corresponding to the inner diameter of the cylindrical portion, and the central portion of the circular body connecting the opposite points of the diameter of the inner circumference circle of the cylindrical portion forms the valve body support portion. And each semi-circular plate portion provided on both left and right sides of the valve body support portion constitutes a valve body,
The valve body is configured to be rotatable via a boundary portion between the valve body support portion and the valve body,
The valve seat is formed by an annular wall surface that protrudes from the inner peripheral surface of the cylindrical portion toward the center line of the cylindrical portion, and is in contact with a surface of the arc edge portion of the valve body near the inner surface of the lining body.
The check valve opening maintaining means includes a check valve opening member, a relay member, a pressing member that presses the check valve opening member, and a check valve opening maintaining member with a water outlet,
The check valve opening member is a bifurcated tip portion having left and right claws that are inserted into the through hole from the inner surface side of the lining body to push open the left and right valve bodies of the check valve, and rearward from the rear end of the bifurcated tip portion. With a shaft part that extends to
The relay member is configured by a cylindrical member, and the cylindrical member includes a threaded portion on a peripheral surface on the one end face side in the direction along the center line, to which a threaded portion of the threaded member of the check valve opening maintaining member is screwed. At the same time, on the peripheral surface on the other end surface side in the direction along the center line, a male screw portion screwed to the female screw portion of the through hole is provided.
The pressing member is provided with an inlet into which the shaft portion of the check valve opening member is inserted at the distal end side, and a sheath pipe portion whose one end is closed, and a direction orthogonal to the central axis of the sheath pipe portion from one end portion of the sheath pipe portion. The left and right horizontal shaft portions provided to be separated from each other,
The check valve open-maintaining member is screwed to the threaded portion of the relay member, and is attached so that both ends of the horizontal shaft portion of the pressing member are pressed against one end surface of the relay member. Is maintained in an open state, and groundwater in the ground is drained to the inside of the lining body through the check valve and the water outlet of the check valve opening maintaining member. The water removing device for the natural ground according to claim 1 or 2. The water drainage device according to claim 4, wherein the check valve opening maintaining member is a three-way switching valve having three inlets and outlets.

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