JP4108460B2 - Construction method of tunnel still water structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a construction method for a tunnel water stop structure. More specifically, the present invention relates to a construction method for a tunnel water stop structure applied to, for example, a watertight tunnel.
[0002]
[Prior art]
In general, the mountain tunnel collects the spring water on the back of the secondary lining and drains it out of the mine via the central drainage groove provided at the bottom of the tunnel, and the spring on the back of the secondary lining is outside the mine. It is divided into watertight type that does not discharge, and in the usual mountain construction (NATM) tunnel, the drainage type that discharges the spring water led to the central drainage channel to the outside of the tunnel by natural flow is often adopted.
[0003]
On the other hand, for example, in urban areas, when spring water cannot be discharged due to natural flow, or to prevent land subsidence, or to reduce maintenance costs for long-term collection and drainage facilities and sewerage usage fees for drainage Therefore, the water tight type is often adopted. Even in mountainous areas, the water drain type may be adopted if the normal drainage type causes a drop in the groundwater level of the surrounding ground and there is a concern about destroying the natural environment.
[0004]
In the case of a watertight type tunnel, unlike the drainage type, the groundwater pressure always acts on the secondary lining and waterproofing, and therefore it is important to form a highly reliable waterproofing layer especially considering watertightness. However, it is difficult to form a waterproof layer with no holes at all during the waterproofing work or after the rebar placement work or secondary lining work, and there are extremely small holes in the waterproof sheet. However, the spring that was pressured after lining erupted from the hole would cause a major water leak accident.
[0005]
Therefore, it is important to incorporate countermeasures in advance on the assumption that there is a possibility that a hole will be formed in the waterproof sheet even if the best waterproofing work is performed. Moreover, no matter how perfect the waterproofing work is done, it is assumed that there are holes in the waterproof sheet, and measures must be taken in advance so that water leakage from the holes does not spread over a wide area.
[0006]
FIGS. 7 to 9 show an example of a conventional general tunnel water stop structure, such as a tunnel wall 2 of a tunnel T formed by excavating the inside of a natural ground 1 or sprayed concrete applied to the wall surface 2 of the tunnel T, etc. The waterproof lining 4 is given to the inner surface of the primary lining 3 and the secondary lining 5 made of concrete is given to the inside thereof. Incidentally, the waterproof Engineering 4 is generally a water-permeable layer 41 made of permeable material or the like as shown in FIG. 9, is composed of a waterproof layer 42 made of a waterproof sheet, etc., nails and bolts as in Figure 9 the aquifer 41 Alternatively, the fixing member 6 such as a hook and loop fastener is attached to the inner surface of the pit wall 2 or the primary lining 3 and the waterproof layer 42 is fixed to the head of the fixing member 6 by welding or the like without forming a through hole. (See, for example, Patent Documents 1 to 3 below).
[0007]
However, since the waterproof layer 42 and the secondary lining 5 are not necessarily in close contact with each other, a gap is often generated, and when the waterproof layer 42 is damaged, the spring that has permeated from the ground is penetrated. Water permeates into the gap from the breakage point b and diffuses widely to the back side of the secondary lining 5 through the gap.
[0008]
Therefore, in order to prevent the above-described water leakage from spreading beyond a predetermined range, for example, as shown in FIG. 9, there are a large number of areas near each joint 5 a of the secondary lining 5 laid at every predetermined span (interval). A water barrier 7 having a water stop rib 7a is installed so that the water leak does not spread to the adjacent span over the water stop rib 7a (see, for example, Patent Documents 3 to 5 below).
[0009]
However, in the conventional method, when a leak occurs, water leakage as shown by the arrows in FIG. 8 will be traveling around the whole one span region surrounded by a water barrier 7, waterproof Engineering 4 of damaged part b Identification becomes difficult. Therefore, it is necessary to repair the entire one span area, which requires a lot of labor and time. Therefore, for example, it is conceivable to reduce the area per one span to reduce the repair range when water leaks. However, the number of installed water barriers 7 increases, and the water barriers 7 are welded to the waterproof sheet in the field. However, in the case of construction, there are problems such as on-site work time, waiting time and construction cost increasing.
[0010]
[Patent Document 1]
Registered Utility Model No. 2596758 [Patent Document 2]
Japanese Patent No. 2928171 [Patent Document 3]
Japanese Patent No. 3241344 [Patent Document 4]
Japanese Patent Publication No. 6-63436 [Patent Document 5]
Japanese Patent No. 2545338
[Problems to be solved by the invention]
The present invention has been proposed in view of the above problems, and even when a damaged portion or the like occurs in waterproofing work such as a waterproof sheet, the leakage area does not spread, and the work time and construction cost in the field It aims to but without increasing, to provide a method of constructing a tunnel waterproofing structure which can be applied easily, inexpensively repair work.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the construction method of a tunnel water stop structure according to the present invention has the following configuration. That is, a primary lining consisting of spray concrete was constructed in tunnel Anakabe surface, between the secondary lining is construction on its inner surface, a permeable layer such as a nonwoven fabric or three-dimensional mesh-like body, the concrete adhesion and a waterproof layer having a construction method of tunnel waterproofing structure formed by interposing a waterproof Engineering laminated integrally, on SL primary lining the inner surface, and the secondary lining construction the back fill material construction for formwork the use mold, are arranged side by side in the tunnel axis direction, the surface of the primary lining side of the back filling material construction for formwork, the waterproof Engineering as the permeable layer side becomes the primary lining side placed Te, and the waterproof Engineering, between the upper Symbol primary lining the inner surface, solidified in a state where the back surface filler by filling a rear filler soaked in water permeability layer of the waterproof Engineering, such as an air mortar by be Rukoto, through the back surface filler is temporarily held in the primary lining the inner surface of the waterproof Engineering, the tentative retention The surface of the waterproof layer side of the waterproof Engineering which is, between the secondary lining construction for formwork, by forming a secondary lining is filled with concrete, a waterproof layer having the above-mentioned concrete adhesion The above-mentioned secondary lining and waterproofing are bonded via an adhesive.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the construction method of the tunnel still water structure by this invention is demonstrated concretely based on embodiment shown in a figure.
[0014]
1 to 3 show an example of a tunnel water stop structure to which the present invention is applied. FIG. 1 is a cross-sectional view in the tunnel transverse direction, FIG. 2 is an enlarged vertical cross-sectional view in the tunnel longitudinal direction, and FIG. FIG.
[0015]
In this example, a primary lining 3 made of sprayed concrete having a predetermined thickness is applied to the upper arch portion 2a and both side portions 2b of the tunnel wall 2 of the tunnel T formed by excavating the ground 1 and the primary covering is performed. A waterproofing work 4 and a concrete secondary lining 5 are provided on the inner surface of the work 3 and the invert part 2c at the lower part of the tunnel over the entire length in the tunnel circumferential direction, and the primary lining on the back surface (outer surface) side of the waterproofing work 4 3, a back filler 8 made of air mortar or the like is interposed. In the figure, 9 is a temporary drainage channel.
[0016]
In the present example, the waterproofer 4 is composed of a water permeable layer 41 and a waterproof layer 42 as shown in FIG. 3, and the water permeable layer 41 includes a cushioning material 41 a such as a nonwoven fabric and a three-dimensional network. It is the structure which laminated | stacked the water-permeable material 41b and buffer materials 41c, such as a nonwoven fabric, in order.
[0017]
Further, as the waterproof layer 42, a sheet material having good adhesion to the secondary lining 5 made of concrete is used. For example, PVA (polyvinyl alcohol) having high affinity with concrete is chemically applied to the sheet surface. A waterproof sheet made of a special EVA (ethylene / vinyl acetate copolymer) resin bonded (grafted) to can be used.
[0018]
In this example, in order from the secondary lining 5 side, a sheet-like concrete adhesive layer made of the special EVA resin as described above, a damage protection layer made of a tough and moderately stretched base fabric, and the like, A waterproof sheet (made by Kuraray Co., Ltd .; trade name “EVABRID”) composed of a waterproof resin layer made of an EVA-based resin having high adhesion and high adhesion with the concrete adhesive layer is used. ing.
[0019]
The PVA swells with moisture at the time of pouring the concrete and protrudes into a fiber at a molecular level in the concrete. When the concrete is cured in this state, the PVA molecule exhibits a wedge effect, and the waterproof layer 42 The secondary lining 5 is firmly bonded to ensure good water-tightness, and the interface between the EVA resin and the concrete is positively and negatively charged to promote bonding by ionic force, and the waterproof layer 42 And the secondary lining 5 are further firmly bonded to each other, and the effect of further improving the watertightness can be exhibited.
[0020]
As described above, in the present invention, the waterproof layer 42 of the waterproofing work 4 and the secondary lining 5 are arranged and fixed in a state where they are completely bonded to each other. Even in this case, the waterproof layer 42 and the secondary lining 5 are bonded in a state of being tightly adhered and there is no gap between them, so that water leakage from the damaged portion b causes the waterproof layer 42 and the secondary lining 5 It does not penetrate between and spread widely. Therefore, if there is water leakage in the tunnel space after the secondary lining has been laid, the water leakage repair only at that location may be performed without causing an increase in the water leakage range.
[002 1 ]
Next, the construction method of the tunnel water stop structure according to the present invention will be described by taking the case of constructing the tunnel water stop structure as described above as an example. 4 and 5 show an example of a construction method when constructing the tunnel water stop structure shown in FIGS. 1 to 3, FIG. 4 is a longitudinal side view of the construction state, and FIG. 5 is an explanation of the construction process. FIG.
[002 2 ]
In this example, the primary lining 3 made of sprayed concrete is applied to the arch portion 2a and both side portions 2b of the tunnel pit wall surface 2 every predetermined span as the tunnel T is dug, and a waterproofing work is performed on the inner surface side with a predetermined interval. In the state where 4 is arranged, after filling the back filler 8 such as air mortar between the waterproof work 4 and the primary lining 3, a secondary lining 5 made of concrete is applied to the inner surface of the waterproof work 4. It is what I did.
[0023]
At that time, the waterproofing work 4 is held at a predetermined interval on the inner surface side of the primary lining 3 and the back side (outside) of the waterproofing work 4 is filled with a back filling material 8 such as air mortar. A back filler construction form 11 for performing the above and a secondary lining construction form 12 for constructing the secondary lining 5 on the inner surface side of the waterproof construction 4 are provided.
[0024]
Each of the molds 11 and 12 is formed with a predetermined width corresponding to the span as shown in FIG. 4 in the tunnel axis direction, and excludes the inverted portion 2c of the tunnel wall surface 2 in the tunnel circumferential direction. It is formed in a size that covers the arch portion 2a and both side portions 2b. Although the above-mentioned molds 11 and 12 are omitted in the drawing, in the present embodiment, each of the molds 11 and 12 is divided into a plurality of pieces in the circumferential direction of the tunnel, and adjacent divided pieces can be expanded and folded in the inner and outer directions of the tunnel cross section. In addition, each of the molds 11 and 12 is configured to be movable independently in the tunnel axis direction in a state where each of the molds 11 and 12 is placed on a movable carriage.
[0025]
FIG. 5 (a) shows a state in which the primary lining 3, the waterproofing work 4, the back surface filling material 8, and the secondary lining 5 are being constructed one by one as the tunnel is dug. First, when a specific thickness of spray concrete is applied as a primary lining 3 to the pit wall 2 of the excavated ground 1, a waterproofing work 4 for one span is deployed on the back filler construction form 11 as shown in the figure. It is placed in a state and is placed at a position that makes a predetermined distance from the inner surface of the primary lining 3. In this case, if the waterproofing work 4 has a multilayer structure composed of the waterproof layer 42 and the water permeable layer 41 and the like as in the present embodiment, it is not separated at least during construction including the constituent materials of those layers. It is desirable to use an integrated device.
[0026]
Then, the waterproof Engineering 4 on the mold 11, used to connect the waterproof Engineering 4 already laid as shown in FIG. 5 (b), this time, the waterproof layer 42, such as a tarpaulin for example ends The water-permeable layers 41 are attached to each other in a watertight manner by welding or the like.
[0027]
Next, as shown in FIG. 5 (c), the hose 13 and the like for injecting the back filler are inserted and arranged from the opening side end portion between the waterproofing work 4 and the primary lining 3 and the opening side end part. Set the inflatable tweezers 14 made of inflatable / shrinkable air tube or the like, and fill the backside filler 8 such as air mortar between the hose 13 and the primary lining 3 on the back side of the waterproofing 4 To do.
[0028]
And when the back surface filler 8 solidifies, the said waterproofing work 4 is temporarily hold | maintained on the inner surface side of the primary lining 3 via the back surface filling material 8, Especially in this embodiment, the water-permeable material 41b. The water-permeable layer 41 including the cushioning material 41a and the waterproof layer previously integrated with the cushioning material 41a such as a nonwoven fabric provided on the primary lining side are solidified in a state in which the back filler 8 such as air mortar soaks. 42. waterproof Engineering 4 whole consisting of is intended to be satisfactorily provisionally hold the primary lining the inner surface through the back filling material 8.
[0029]
Then, at the construction of the back filling material 8 as described above has been completed, or, and in parallel, the secondary lining construction mold which was constructed a secondary lining in the previous step as shown in FIG. 5 (a) The frame 12 is moved and arranged at the next secondary lining construction position as shown in FIG. 5B, and concrete is filled between the mold 12 and the waterproofing work 4 previously constructed, so that the secondary lining is performed. 5 is formed.
[0030]
The concrete filling method and the like are appropriate. For example, one end side (left side in the figure) of the space between the secondary lining construction form 12 and the waterproofing work 4 is connected to the mold 12 and the waterproofing work 4. Concrete is put into the space from a through-hole (not shown) formed in the thickness direction, for example, at the uppermost part of the formwork 12 for secondary lining construction. What is necessary is just to fill.
[0031]
By filling concrete between the formwork 12 and the waterproofing work 4 as described above and forming the secondary lining 5 on the inner surface side of the waterproofing work 4, the waterproofing work 4 and the secondary lining 5 are formed. Waterproofing made of a special EVA resin that is bonded to each other and is chemically bonded to the sheet surface as described above, in particular PVA having a high affinity with concrete as the waterproofing layer 42 of the waterproofing work 4. When a sheet is used, the PVA swells with the moisture of the concrete and solidifies in a state of protruding into a fiber at a molecular level in the concrete, and the wedge effect of the PVA molecules and the ionic bond between the EVA resin and the concrete Bonding can be performed in a state where the entire joint surface between the waterproof layer 42 and the secondary lining 5 is firmly adhered.
[0032]
Also between the primary lining 3 on the rear side of the waterproof Engineering 4 as described above, when the waterproof Engineering 4 by filling the back filling material 8, such as an air mortar Ru is temporarily held, waterproof Engineering as the conventional The next secondary lining 5 can be constructed without the troublesome work of fixing 4 with a fixing member such as a nail or bolt. In addition, in the event that the waterproofer 4 is damaged, the waterproofer 4 and the secondary lining 5 are bonded in a state of being in close contact with each other, so that water leakage from the damaged part may spread widely. In addition, it is easy to identify a damaged portion, and when repairing, it is only necessary to repair the damaged portion, so that the work is easy and the repair can be easily and reliably performed.
[003 3 ]
Note invert portion 2c of the tunnel bottom, without providing a back filling material 8, it is possible to position held only at a predetermined position for mounting the waterproof Engineering 4 in the natural ground or the inner surface of the primary lining (upper surface) Since the concrete for secondary lining can be directly placed on the upper surface, the mold 11 as described above becomes unnecessary in such a case. The construction of the invert part 2c may be carried out continuously after or before the construction of the arch part 2a and both side parts 2b.
[003 4 ]
The arch 2a, particularly the top end, is likely to have a gap with the waterproofing 4 when constructing the concrete for secondary lining. As shown in FIG. 4 , the concrete is placed in a state where the contact grout tube 15 is previously installed at a predetermined pitch in the vicinity of the top end, and when the concrete is hardened to some extent, the contact grout tube 15 is waterproofed. If a grout material such as cement milk or mortar is injected into the inner surface of the work 4, it is possible to more reliably prevent a gap from being formed between the waterproofing work 4 at the top end and the secondary lining 5. Become.
[003 5 ]
Further, in the embodiment described above, a waterproof sheet made of a special EVA resin having an adhesive property to the secondary lining 5 is used as the waterproof layer 42 of the waterproof work 4, using an ionic bond with concrete. It is not limited to this as long as it has adhesiveness to the secondary lining 5, and for example, as shown in FIG. 6 , at least two waterproof layers 42 made of a water-impermeable synthetic resin sheet such as EVA resin are used. By making the surface on the side of the next lining 5 fluffed, a waterproof sheet or the like that can be bonded and bonded in a state in which the raised 42 a enters the secondary lining 5 can be used.
[003 6 ]
【The invention's effect】
As described above, since the construction method of the tunnel water stop structure according to the present invention is such that the waterproofing 4 and the secondary lining 5 are bonded as described above, both can be bonded closely together. It is possible to prevent a gap from being generated between the two and causing damage. Moreover, even if the waterproofing work is damaged, it is possible to prevent water leaked from the damaged portion from entering between the two and spreading widely. As a result, it becomes easy to detect a damaged portion, and when repairing, only the damaged portion needs to be repaired, so that the work is easy, and it is possible to repair easily and inexpensively.
[Brief description of the drawings]
FIG. 1 is a cross-sectional front view showing an example of a tunnel water stop structure to which the present invention is applied.
FIG. 2 is an enlarged vertical sectional view of a part of the tunnel water stop structure.
FIG. 3 is an enlarged cross-sectional view of a waterproofing construction used for the tunnel water stop structure.
FIG. 4 is a longitudinal side view showing an example of a construction method for a tunnel water stop structure according to the present invention.
FIG. 5 is an explanatory diagram showing the construction process of the tunnel water stop structure.
FIG. 6 is a cross-sectional view showing a modified example of waterproofing work.
FIG. 7 is a cross-sectional front view showing an example of a conventional tunnel water stop structure.
FIG. 8 is a longitudinal side view of the tunnel water stop structure.
FIG. 9 is an enlarged vertical side view of a part of the tunnel water stop structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ground mountain 2 Wall surface 2a Upper arch part 2b Left and right both sides 2c Invert part 3 Primary lining 4 Waterproofing work 41 Water permeable layer 41a, 41c Buffer material 41b Water permeable material 42 Waterproof layer 5 Secondary lining 8 Back surface filling

Claims (3)

Waterproof having a primary lining consisting of spray concrete was constructed in tunnel Anakabe surface, between the secondary lining is construction on its inner surface, a permeable layer such as a nonwoven fabric or three-dimensional mesh-like body, the concrete adhesion It is a construction method of a tunnel water-stopping structure with a waterproof construction that integrally laminates layers,
On SL primary lining the inner surface, and a back filling material construction for formwork secondary lining construction for formwork, and arranged in the tunnel axis direction,
The surface of the primary lining side of the back filling material construction for formwork, the waterproof Engineering was placed as the water-permeable layer side becomes the primary lining side,
Its waterproof Engineering, between the upper Symbol primary lining the inner surface, by Rukoto be solidified in a state where the back surface filler by filling a rear filler soaked in water permeability layer of the waterproof Engineering such as an air mortar, Temporarily holding the waterproof work on the inner surface of the primary lining through the back filler ,
By filling the concrete between the surface of the waterproof layer of the waterproof work that has been temporarily held and the formwork for the secondary lining construction to form the secondary lining, the above concrete adhesiveness is achieved. A construction method for a tunnel water stop structure, characterized in that the secondary lining and the waterproof work are bonded through a waterproof layer.   The construction method for a tunnel waterproof structure according to claim 1, wherein a waterproof sheet made of EVA resin obtained by chemically bonding PVA to the sheet surface is used as the waterproof layer having concrete adhesiveness.   When forming a secondary lining by filling concrete between the waterproof construction and the secondary lining construction formwork, the concrete is placed with a contact grout pipe installed in the vicinity of the top of the tunnel. 3. The tunnel waterproof structure according to claim 1, wherein after the filling, a grout material such as cement milk or mortar is injected between the waterproofing work and the secondary lining through the contact grout pipe. Construction method.

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