JPH10317897A - Flow obstruction preventive structure of groundwater and segment piece and segment ring therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the flow obstruction of groundwater. SOLUTION: An annular water pipe 2A along the peripheral direction is installed into the peripheral wall of an underground structure 1A constructed by underground excavation, and water-collecting means 4, 4 projected into a ground through the water pipe 2A are mounted on the upstream side in the direction of the flow of groundwater in the underground structure 1A and discharge means 5, 5 projected into the ground through the water pipe 2A on the downstream side reverse to the water-collecting means 4, 4. Groundwater on the upstream side of the underground structure 1A is collected by the water- collecting means 4, 4 and introduced into the water pipe 2A, reaches the discharge means 5, 5 through the water pipe 2A, and discharged to the downstream side from the discharge means 5, 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing the flow of groundwater from being hindered in an underground structure constructed based on underground excavation in an uncut state.

[0002]

2. Description of the Related Art When underground structures such as road tunnels and railway tunnels are constructed on ground with groundwater flow, short-term or long-term groundwater flow obstruction occurs.
This causes problems such as the settlement of the surrounding ground and difficulty in securing well water.

[0003] For example, as shown in FIG.
When 00 is located over the permeable layer and the poorly permeable layer or the impermeable layer (hereinafter, simply referred to as the poorly permeable layer), the flow of groundwater is obstructed. In the illustrated example, the groundwater surface h1 on the upstream side with the underground structure 100 interposed therebetween.
Rises to a position h2 exceeding the uppermost part of the underground structure 100, while the groundwater surface h3 on the downstream side falls to a position h4 below by the rising amount. For this reason, land subsidence and well water securing become difficult on the downstream side in the groundwater flow direction of the underground structure 100.

[0004] Even if the underground structure does not straddle the permeable layer and the poorly permeable or impermeable layer, for example, if the underground structure is located in the groundwater flow path, the flow of groundwater is hindered. .

Conventionally, when an underground structure is constructed by an open-cutting method, as shown in FIG.
Vertical shafts 111 and 112 for collecting and discharging water are formed on the upstream side and the downstream side, respectively, and these are communicated by the horizontal shaft 113 formed in the low-permeable layer below the underground structure 110. It prevented the groundwater flow from being hindered. Also, a water pipe is provided along the outer periphery of the underground structure, and a water permeable region is similarly formed.

[0006]

However, the unconsolidated ground containing water is constructed by such a construction method even though a construction method for constructing an underground structure by underground excavation such as a shield construction method is generally employed. There have been no effective proposals to prevent groundwater flow obstruction caused by underground structures.

That is, when constructing an underground structure by the excavation method, it is relatively easy to provide a water pipe along the outer periphery of the underground structure or to form a water-permeable region, It cannot be applied to the method of constructing underground structures by underground excavation in the state.

[0008] Further, even when an underground structure is constructed by underground excavation, a vertical shaft and a horizontal shaft for water passage can be formed as in the conventional example described above, but the work is large. It is not preferable because the scale becomes large.

Accordingly, a main object of the present invention is to prevent the underground structure constructed by underground excavation from obstructing the flow of groundwater, and thereby to preserve the groundwater environment in the surrounding ground. Another object of the present invention is to simplify the work for preventing the flow of groundwater from being hindered.

[0010]

SUMMARY OF THE INVENTION The present invention, which has solved the above-mentioned problems, has a feature of forming a water passage from one side to the other side of an underground structure constructed based on underground excavation. It has a flow inhibition structure.

In the present invention, it is preferable that the water passage is constructed by at least one of a water pipe and a layer made of a water-permeable material. A water collecting means communicating with the water passage and collecting groundwater on one side of the underground structure; and a water discharging means communicating with the water passage and discharging groundwater on the other side of the underground structure. It is preferable to provide at least one of the above. Furthermore, it is proposed that the underground structure is a shield tunnel constructed by a shield method or a tunnel constructed by a concrete spraying method.

On the other hand, as an apparatus for applying the structure for preventing groundwater flow obstruction of the present invention to a shield tunnel constructed by a shield method, a method of connecting a circumferential connection surface from one side to a circumferential connection surface on the other side. A segment piece is proposed which comprises a water pipe extending close to the surface.

[0013] Further, in this segment piece, there is also proposed a segment piece having an opening at least on the side of the ground and having a water passage hole communicating with the water passage pipe.

[0014] Further, a segment ring characterized by being provided with an integral water pipe extending in the circumferential direction on the peripheral wall, and having a water hole that opens at least on the side of the ground and communicates with the water pipe. Suggested.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, an underground structure constructed based on underground excavation (the underground structure according to the present invention has a sectional shape The water passage is formed from one side to the other side of the underground structure (for example, the shape may be circular or irregular). A mode in which a water passage is formed near the outside may be considered.

That is, first, assuming that a water passage is formed in the underground structure, as shown in FIG.
Water pipe 2 extending in the circumferential direction and having an annular shape
An embodiment in which A is provided (first embodiment) is considered. In the illustrated example, water collecting means 4 and 4 communicating with the water pipe 2A and protruding into the ground are provided on the upstream side in the groundwater flow direction of the underground structure 1A, and the water collecting pipe 2A is provided on the downstream side opposite thereto. Water discharge means 5 and 5 are provided that communicate with and protrude into the ground. In this case, the groundwater on the upstream side of the underground structure 1A is collected by the water collecting means 4, 4 and introduced into the water pipe 2A, and then reaches the water discharging means 5, 5 via the water pipe 2A. Water is discharged downstream.

As a modified example of this embodiment, as shown in FIG. 2, an annular water pipe 2B extending in the circumferential direction is provided on the inner cavity side of the underground structure 1B (second embodiment). Can be considered. On the contrary, a mode (third mode) in which an annular water pipe 2C is provided outside the underground structure 1C as shown in FIG. 3 is also conceivable. Also in these embodiments, the groundwater is the groundwater upstream of the underground structure 1B (or 1C), the collecting means 4 and 4 and the water pipe 2B (or 2).
C) and the water discharging means 5, 5 in this order, and the water is discharged downstream. The second and third aspects include those in which a water pipe is embedded in the outer surface of the peripheral wall or the inner surface of the peripheral wall of the underground structure.

Further, an embodiment (fourth embodiment) in which a transverse water passage crossing the internal cavity is provided in the underground structure is also conceivable. For example, as shown in FIG. 4, an annular water pipe 2B ′ is provided on the inner cavity side of the underground structure 1B ′ according to the second embodiment, and inside the partition wall 6 that divides the inner cavity into upper and lower two stages, A transverse water pipe 7 that connects the upstream part and the downstream part in the flow direction of the groundwater in the water pipe 2B ′ is provided.
In this case, the transverse water pipe may be provided along the outer surface of the partition wall. In addition, even when a water passage is constructed according to the first and third embodiments, and when a water passage is formed according to a fifth embodiment described below, the transverse water passage described herein can be provided. .

As a mode of forming a water passage near the outside of the underground structure, as shown in FIG. 5, a layer 2D made of a water-permeable material is provided so as to surround the outside of the underground structure 1D (fifth embodiment). Aspect) is conceivable. As the water permeable material, sand having high water permeability such as mountain sand, water permeable concrete, and the like can be considered. In this case, as shown by the arrow in the figure, the groundwater on the upstream side of the underground structure 1D is made of a layer 2D made of a water-permeable material.
The water is passed downstream through.

In these illustrated embodiments, the water passages are formed on both the upper and lower sides of the underground structure. However, the present invention is not limited to this. For example, only the upper side or only the lower side of the underground structure is provided. A water passage can be formed. Only the above-mentioned cross water channel may be provided. From the viewpoint of water permeability,
It is preferable to form a water passage at least below the underground structure. Further, the above-described embodiment in which the water passage is formed only on the upper side or only below the underground structure, and the above-described first to fifth embodiments can be appropriately combined. For example, the water pipe according to the first aspect (second, third or fourth aspect) is provided and a layer made of the water-permeable material according to the fifth aspect is formed, or the water pipe according to the first aspect is provided. In addition, the water pipe of the second mode (or the third mode) can be provided. In the present invention, the angle between the flow direction of the groundwater and the flow direction of the water passage (the direction connecting the water collecting portion and the water discharge portion in the water passage) can be appropriately determined.

On the other hand, these embodiments are applicable to a shield tunnel constructed by a shield method, a tunnel constructed by a concrete spraying method such as a NATM method, and the like.
Applies to underground structures constructed based on underground excavation in uncut conditions. Therefore, next, for the shield tunnel constructed by the shield method,
The case where the water passage according to the embodiment is formed will be described more specifically.

First, similar to the ordinary shield method, a segment piece is manufactured prior to on-site construction. The segment type may be any of a reinforced concrete (RC) segment, a composite segment, a steel segment, and a ductile segment.

The segment piece 11 according to the present invention includes a unit water pipe 13a as shown in FIGS. The unit water pipe 13a generally extends from the circumferential connection surface on one side of the segment piece 11 to the circumferential connection surface on the other side, but both ends do not reach the respective connection surfaces. Alternatively, the water pipe may extend from the circumferential connection surface on one side to the circumferential connection surface on the other side. In this case, the end of the water pipe of one segment piece can be automatically connected to the end of the water pipe of the other segment piece connected thereto by connection of the segment pieces described below, which is preferable. . In addition, since a connecting box 23 and a connecting pipe 24 to be described later are not used, it is also preferable in that the connecting work associated therewith becomes unnecessary.

The segment piece 11 includes a unit water pipe 13
Except for having a, it is basically the same as the known one,
A grout hole 22 communicating with the inner side of the segment and the ground side at substantially the center thereof, a circumferential joint (so-called inter-segment joint) 20, 20,... So-called ring-to-ring joints 21, 21 on the side in the tunnel extension direction that enable connection with other segment rings
... The unit water pipe 13a is a grout hole 22.
Provided to lead to. Further, as shown in FIG. 8, in order to connect the other segment piece to the unit water pipe 13 a, the end of the unit water pipe 13 a is exposed on both sides in the circumferential direction so that the inner surface of the segment is exposed. An open connection box 23 is provided. For example, in the case of a reinforced concrete segment, the unit water pipe 13a may be passed between the reinforcing bars F as shown in FIG.

In the on-site construction, the segment piece 11 is carried into the rear of the shield machine and connected to the respective circumferential joints 20, 20,. (See FIG. 10).
In this example, the water collecting pipes 14, 14 and the water discharging pipes 15, 15
Is assembled using the grout holes 22, 22, so that the segment rings 12 are assembled so that the grout holes 22, 22... Are located at appropriate positions on the upstream and downstream sides of the groundwater flow. Water collection pipes 14, 14 and water discharge pipe 1
The mounting holes 5 and 15 can be provided at arbitrary positions different from the Glalt holes 22.

Next, as shown in FIG. 11, the grout material G is back-filled and injected through the respective grout holes 22, 22,.
Using a drilling machine, drill holes to a depth corresponding to the length of 14 (or water discharge pipes 15, 15). In this case, if the geology is rock, a rock drill can be used. Holes may be drilled by hand if necessary. The holes thus formed are provided in the collecting pipes 14 and 14 (or in the discharging pipe 1).
5, 15). 25, 25 ... are caps.

Subsequently (or in parallel), the ends of the adjacent unit water pipes 13a, 13a are connected to each other, and an integral annular water pipe 13 is formed inside the peripheral wall of the segment ring 12.
To build. Specifically, as shown in FIGS. 12 and 13, the ends of the unit water pipes 13 a protruding into the connection boxes 23 are connected via a connection pipe 24. Preferably, a flexible tube is used as the connection tube 24 to facilitate connection. When the connection of the water pipes is completed, mortar is poured into the connection boxes 23, 23,.

Furthermore, secondary lining of the inner surface of the segment is performed as required, such as smoothing and makeup of the inner surface, correction of meandering generated during shield construction, reinforcement of the segment, corrosion protection of the tunnel, and the like. Thereafter, the above-described operation is repeated with the excavation of the shield machine, and the shield tunnel 10 is completed.
In the completed shield tunnel 10, after the groundwater on the upstream side is guided to the water pipe 13 by the water collecting pipes 14, 14, the drain pipe on the opposite side mainly passes through the lower water pipe 13 in the case of the drawing. It reaches 15,15, from which it is released again into the ground. For this reason, similarly to the example shown in FIG. 1 described above, even when the shield tunnel 10 is located straddling the permeable layer and the poorly permeable layer, the flow of the groundwater is not hindered. In addition, the unit piece water pipe 13 is
Since a is installed, work on site can be simplified.

Here, according to the first embodiment described above,
The example in which the water pipe is provided inside the peripheral wall of the shield tunnel has been described. The same applies to the case where the water pipe is provided according to the second and third embodiments.

That is, although not shown, a water pipe may be provided along the inner surface or outer surface of the segment piece.
However, when the water pipe is provided along the outer surface of the segment piece, it is necessary to open the connection box to the ground side in order to connect the water pipe at the time of assembling the segment piece. When the water pipe is arranged along the inner surface of the segment piece (excluding the case where the water pipe is embedded in the inner surface), the connecting box is not required. In particular, in this case, the water pipe can also be arranged on site, for example, after assembling the segment ring.

In the case of constructing a transverse waterway according to the fourth aspect, in constructing a partition wall, a transverse water pipe is previously arranged inside or along the outer surface of the partition wall, and the water is passed through the pipe. What is necessary is just to connect to a water pipe, a water collection means, and a water discharge means. Further, after the partition wall is constructed, a transverse water pipe may be provided along the outer surface of the partition wall and connected to the water pipe, the water collecting means, and the water discharging means (not shown).

When constructing a shield tunnel having a layer made of a water-permeable material on the outer surface side according to the fifth embodiment, a segment piece similar to the ordinary shield method is used, and instead of a grout agent that is usually used,
Backfilling may be performed using a highly permeable sand such as mountain sand or an injecting agent that becomes permeable concrete in the same manner as a normal shield method (not shown).

On the other hand, even when the structure for preventing groundwater flow obstruction of the present invention is applied to a concrete spraying method such as the NATM method, the water passages described in the first to fifth aspects are constructed. be able to.

That is, in order to construct the water channel according to the first aspect in the concrete spraying method, after the primary spraying is performed on the tunnel excavation surface and before the secondary spraying, an appropriate spraying of the primary spraying surface is performed. At the position, a mounting hole for the water collecting pipe and the water discharge pipe is drilled, and a water collecting pipe and a water discharging pipe are attached to the mounting hole, and a water pipe communicating with the water collecting pipe and the water discharging pipe is arranged in the circumferential direction of the tunnel. by this,
A water pipe can be provided between the primary spraying surface and the secondary spraying surface, that is, inside the peripheral wall of the tunnel.

In order to construct the water channel of the second embodiment, after at least the secondary spraying is performed in the same manner as in a normal construction method, the water collecting pipe and the discharge pipe are placed at appropriate positions with respect to the secondary spraying surface. A mounting hole for the water pipe is drilled, and a water collecting pipe and a water discharge pipe are attached to the mounting hole, and a water pipe communicating with the water collecting pipe and the water discharging pipe is arranged in a circumferential direction of the tunnel.

Thus, a water pipe can be provided on the inner surface side of the secondary spray surface, that is, along the inner surface of the peripheral wall of the tunnel.

In order to construct the water passage of the third embodiment, holes for mounting the water collecting pipe and the water discharge pipe are drilled at appropriate positions on the tunnel excavation surface, and the water collecting pipe and the water discharging pipe are inserted into the mounting holes. At the same time as mounting, the water pipes communicating with the water collection pipe and the water discharge pipe are arranged in the circumferential direction of the tunnel, and then the primary spraying, the secondary spraying, etc. are performed in the same manner as a normal construction method. Thereby, a water pipe embedded on the outer surface side of the primary spraying surface, that is, on the outer surface of the peripheral wall of the tunnel can be provided.

In the concrete spraying method, the case of constructing the water passage of the fourth embodiment is the same as the case of the shield tunnel.

In order to construct the water passage of the fifth aspect, the outer portion of the peripheral wall of the tunnel is sprayed with the permeable concrete as a primary spray to the tunnel excavation surface or as a preliminary spray before the primary spray. Or a layer made of permeable concrete can be provided on the outer side of the peripheral wall of the tunnel.

<Others> (1) Examples of the water pipe according to the present invention include a flexible pipe such as a rubber flexible hose, an inflexible pipe such as FRP and vinyl chloride resin, and a metal such as stainless steel. And the like can be used. Among these, those which are resistant to acid and rust and have little deterioration over time are desirable. It should be noted that the water pipe according to the present invention includes a tubular path formed by a hole provided in the peripheral wall of the underground structure (that is, a hole in which the peripheral wall material is exposed on the inner wall), unlike the pipe as these members.

(2) As the water collection pipe and the water discharge pipe according to the present invention, a so-called strainer pipe having a large number of communication holes in the peripheral wall of the pipe can be used.

(3) In the present invention, in order to prevent sand or the like from flowing into the water pipe or clogging due to the sand or the like, a filter can be provided in the water collection pipe / water discharge pipe. As the material of the filter, various kinds of sand, activated carbon, cloth (including nonwoven fabric, etc.) and the like can be used.

(4) When a filter is installed in the water collection pipe / water discharge pipe, it is assumed that the filter is clogged. For this reason, it is preferable to use a cartridge-type filter so that it can be replaced as needed. For example, in the above shield tunnel example, a cartridge type filter is used, and the cap 25 is made detachable. In particular, when performing secondary lining, the cap 25 is not wrapped. Thus, when the filter is clogged, the cap 25 can be removed to replace the filter.

(5) In the present invention, an appropriate position of the water passage, for example, in the case of the above-mentioned shield tunnel, the cap 2
A pump can be installed at the communicating portion between the water pipe and the water collecting pipe or the water discharge pipe covered by 5 to force water to flow. In addition, the pump can be used to return to the same side as the water collecting side for prevention of land subsidence, protection of well water, adjustment of groundwater flow, and the like.

(6) In the present invention, when a filter is installed in the water collection pipe / water discharge pipe, a pump is installed at an appropriate position in the water passage, the communication part described in (5) above, and the groundwater is supplied. It can also be reversed in the opposite direction to remove sand clogged in the filter. In this case,
A condensate pump can also be used.

(7) In the present invention, a manometer or the like can be installed in the water passage to measure the water head on the water collection side and the water discharge side. Further, if a pore water pressure gauge or a flow meter is provided in the water passage, the flow rate and the flow velocity of the groundwater can be measured. In addition, particularly when the water pipes are arranged along the inner surface of the underground structure as in the second aspect described above, it is possible to check the water flow and observe the water quality by using a transparent water pipe. it can.

(8) In the present invention, selection of a water passage and a water passage means (layer made of a water passage pipe and a water permeable material) for an underground structure, availability of a water collection pipe / water discharge pipe, and availability of a filter The installation of a means to prevent filter clogging, the installation of a pump, etc. are based on the soil conditions of the ground (permeability, groundwater pressure, geological composition, water quality, etc.) and the surrounding environment (rivers, wells, spring water sources). And the positional relationship between the underground structure and the flow direction of the groundwater).

[0048]

As described above, according to the present invention, it is possible to prevent the underground structure constructed by underground excavation from obstructing the flow of groundwater, thereby preserving the groundwater environment in the surrounding ground. Accordingly, the operation can be simplified.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a third embodiment of the present invention.

FIG. 4 is an explanatory diagram of a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram of a fifth embodiment of the present invention.

FIG. 6 is a diagram showing a plane and a cross section of a segment piece.

FIG. 7 is a diagram showing a side surface and a vertical cross section of a segment piece.

8 is a view taken in the direction of arrows II-II in FIG.

FIG. 9 is a sectional view taken along the line III-III in FIG. 6;

FIG. 10 is a longitudinal sectional view of a shield tunnel.

FIG. 11 is an enlarged view of a part IV in FIG. 10;

FIG. 12 is an enlarged view of a portion V in FIG. 10;

FIG. 13 is a plan view of FIG.

FIG. 14 is an explanatory diagram of groundwater flow inhibition.

FIG. 15 is an explanatory diagram of a conventional example.

[Explanation of symbols]

1A-1D: underground structure, 2A-2C: water pipe, 2C ...
A layer made of a water-permeable material, 4 ... water collecting means, 5 ... water discharging means,
6: Partition wall, 7: Crossing waterway.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Norio Uno 6-14-1, Nishishinjuku, Shinjuku-ku, Tokyo Inside Sato Kogyo Co., Ltd. Tokyo Branch (72) Inventor Kunihiro Hirayama 6-14, Nishishinjuku, Shinjuku-ku, Tokyo No. 1 Sato Kogyo Co., Ltd. Tokyo Branch (72) Inventor Toru Moriyama 6-14-1, Nishi Shinjuku, Shinjuku-ku, Tokyo Sato Kogyo Co., Ltd. Tokyo Branch

Claims (7)

[Claims] 1. A structure for preventing flow of groundwater, wherein a water passage leading from one side to the other side of an underground structure constructed based on underground excavation is formed. 2. The structure according to claim 1, wherein said water passage is constructed by at least one of a water pipe and a layer made of a water-permeable material. 3. A water collecting means communicating with the water passage and collecting groundwater on one side of the underground structure, and discharging water from the groundwater on the other side of the underground structure and communicating with the water passage. 3. The structure for preventing flow of groundwater according to claim 1, wherein at least one of water discharging means is provided. 4. The underground structure is a shield tunnel constructed by a shield method or a tunnel constructed by a concrete spraying method.
4. The structure for preventing flow inhibition of groundwater according to any one of the above items. 5. A segment piece comprising a water pipe extending from the vicinity of one circumferential connection surface to the vicinity of the other circumferential connection surface. 6. The segment piece according to claim 5, wherein a water passage hole is provided at least on the side of the ground and provided with a water passage hole communicating with the water pipe. 7. A segment ring comprising: an integral water pipe extending in a circumferential direction on a peripheral wall; and a water hole that is opened at least on a ground side and that communicates with the water pipe.