JP6156973B2 - How to build a tunnel structure - Google Patents

Description

The present invention relates to a tunnel structure waterproofing process is performed, in particular to a method for constructing a tunnel structure which lining concrete on the inside of the waterproof sheet is Da設while forced sucking air.

  In the mountain tunnel, as shown in FIG. 7, supporters 2 are installed at a predetermined pitch on the pit wall 1 a excavated in the ground 1, sprayed concrete 3 of the primary lining is sprayed, and lock bolts 4 are driven. A structure in which a waterproof sheet 5 is laid inside the shotcrete 3 and a lining concrete 6 as a secondary lining is placed inside the waterproof sheet 5 is common.

  When placing the lining concrete 6 for the secondary lining in this tunnel structure, a mold frame is installed inside the waterproof sheet 5 and the lining concrete 6 is cast in the space between the mold frame and the waterproof sheet. However, since concrete is filled from the lower side in the formwork, a gap S1 that is not filled with the lining concrete 6 tends to remain in the vicinity of the top end portion (arch crown portion) of the tunnel. If there is such a gap S1, when the waterproof sheet 5 is damaged, the spring water of the natural ground 1 enters the gap S1 from the damaged portion and diffuses from the gap S1 to the back surface or the joint of the lining concrete 6. Water leakage will occur.

  Therefore, in order to reliably fill and place the lining concrete near the top edge of the lining concrete joint and near the top edge between joints, the joint with the existing lining concrete is placed. At the position corresponding to, the perforated hose is arranged in an arc shape along the circumferential direction of the tunnel and fixed on the inner surface of the waterproof sheet, and the lining concrete is cast while forcibly sucking air with the arc-shaped perforated hose, Proposed to place a porous hose in a straight line in the tunnel axis direction on the inner surface of the waterproof sheet and fix it on the inner surface of the waterproof sheet while forcibly sucking air with the straight porous hose. (See Patent Documents 1 and 2).

JP 2005-179891 A JP-A-2005-90151

  By the way, the waterproof sheet 5 having the tunnel structure of FIG. 7 is partially fixed and laid on the shotcrete 3 with a ridge or the like and is spread unevenly, so that the stress state becomes uneven and the durability of the waterproof sheet 5 is increased. Sex is reduced. In addition to the partial fixing of the waterproof sheet 5, the waterproof sheet 5 is not in close contact with the shotcrete 3 due to the unevenness of the inner surface of the shotcrete 3. There is a gap S2 between them, but this gap S2 becomes a factor that collects spring water from the natural ground 1 at a specific location of the waterproof sheet 5, and therefore the waterproof sheet 5 is easily damaged.

  In particular, in the construction method in which the perforated hose is fixed to the inner surface of the waterproof sheet and the lining concrete is placed while forcibly sucking air, the waterproof sheet is pulled inward by decompression. The uniformity and the spread of the gap S2 on the back side of the waterproof sheet are further increased, and the certainty and durability of waterproofing are further reduced.

The present invention is proposed in view of the above problems, and even if the lining concrete is placed while forcibly sucking air by fixing a breathable hose to the inner surface of the waterproof sheet, the waterproof sheet is stretched or stressed. construction of it is possible to ensure uniformity, it is possible to eliminate both the gaps on the rear side of the air gap and the inner side of the tarpaulin, the tunnel structure of the waterproof effect can be obtained which is excellent in reliability and durability It aims to provide a method.

The tunnel structure construction method of the present invention includes a step of placing a waterproof sheet in close proximity to an arch portion of a natural mountain or an arch portion of a primary lining material, and a space between the arch portion and the waterproof sheet. A step of fixing the solidified layer formed by solidifying the filler to the arch portion and the back surface of the waterproof sheet, and a T-type in which the base tube and the branch tube have air permeability Using a hose, the branch pipe is extended along the top of the inner surface of the waterproof sheet laid in an arch shape, and the branch pipe is placed at a position corresponding to the joint with the already placed lining concrete. Extending in an arc from the top to both shoulders along the inner surface of the waterproof sheet, fixing the base tube and the branch tube to the inner surface of the waterproof sheet, and a rear end opening of the base tube Place the formwork so that it pulls out from the end plate, Air is forced into the rear end opening of the base tube from any time point during the placement process, and air in the placement space is formed using a breathable material constituting the base tube and the branch pipe as a filter. By placing the lining concrete while forcibly sucking in, the base pipe and the branch pipe are provided in close contact with the lining concrete so as to be substantially along the inner surface of the waterproof sheet. And a step of forming engineered concrete .
According to this configuration, since the waterproof sheet is fixed by the consolidated layer formed of the filler, the lining concrete is placed while the air-permeable hose is fixed to the inner surface of the waterproof sheet and the air is forcibly sucked. However, the waterproof sheet is not pulled inward by decompression, and the waterproof sheet can be stretched and the uniformity of the stress state can be ensured. In addition, there is no void on the back side of the waterproof sheet with the consolidated layer, and there is no void on the inner surface side of the waterproof sheet near the top end with lining concrete that is cast while forcibly sucking air. It is possible to eliminate both the gap and the gap on the inner surface side. Therefore, it is possible to obtain a waterproof tunnel structure with excellent reliability and durability. Furthermore, because it is possible to perform forced suction of air with the entire length of the T-type hose, the number of hoses generated in the work space in the tunnel can be reduced, construction management can be facilitated, and it is necessary for forced suction. The number of simple suction pumps can be reduced to one, and the number of construction equipment and construction costs can be reduced.

In the tunnel structure construction method of the present invention, the T-type hose is connected to the base pipe and the branch pipe via a T-type joint, and each of the base pipe and the branch pipe has air permeability and water permeability. It is comprised from the cylindrical textile fabric which has.
According to this configuration, it is possible to use a tubular fabric having the same configuration as a base tube and a branch tube, and the manufacturing cost of the T-type hose can be reduced. Moreover, only the excess water in air and concrete can be attracted | sucked, without drawing in earth and sand and a cement component, using the fiber of a cylindrical fabric as a filter.

  According to the present invention, even if the lining concrete is placed while fixing a breathable hose on the inner surface of the waterproof sheet and forcing air to be sucked, it is possible to ensure the uniformity of the waterproof sheet and the stress state. In addition, it is possible to eliminate both the gap on the back side and the gap on the inner surface side of the waterproof sheet, and a waterproof effect excellent in certainty and durability can be realized.

The cross-sectional view which shows the top end vicinity of the tunnel structure of embodiment of this invention. The perspective explanatory view showing the T type hose installed in the tunnel structure of the embodiment. (A) is a plan view of a T-type hose, (b) is a perspective view of a T-type joint of a T-type hose, (c) is a cross-sectional view showing a part of the cross-section of a base pipe (branch pipe), (d ) Is a longitudinal sectional view showing a part of a longitudinal section of a base tube (branch tube). (A)-(c) is a cross-sectional view which shows the front | former stage of a work process in the construction method of the tunnel structure of embodiment. (A)-(c) is a cross-sectional view which shows the back | latter stage of a work process in the construction method of the tunnel structure of embodiment. The flowchart which shows the work procedure in the construction method of the tunnel structure of embodiment. (A) is a cross-sectional view showing the vicinity of the top end of a conventional tunnel structure example, and (b) is a vertical cross-sectional view of a conventional tunnel structure example.

[Method for constructing tunnel structure of embodiment]
In the tunnel structure according to the embodiment of the present invention, as shown in FIG. 1, spray concrete 11 is provided as a primary lining material on an arch portion 10 a of a natural ground 10, and a waterproof sheet is provided inside the arch portion 11 a of the shot concrete 11. 12 is laid. A filling layer 13 is formed by filling a filler between at least the inner surface of the arch part 11 a of the shotcrete 11 and the waterproof sheet 12, and the consolidated layer 13 is formed between the inner surface of the arch part 11 a and the waterproof sheet 12. It adheres to the back. In addition, description of a support work and a lock bolt is abbreviate | omitted in the structure of the example of illustration.

  As shown in FIGS. 1 to 3, a T-type hose 14 in which a base pipe 141 and a branch pipe 142 are connected by a T-type joint 143 is fixed to the inner surface of the waterproof sheet 12. 142 is fixed to the inner surface of the waterproof sheet 12.

  Each of the base tube 141 and the branch tube 142 is a seamless tubular woven fabric having air permeability and water permeability, and is formed by weaving fibers into a tubular shape. In this example, as shown in FIGS. 3C and 3D, the warp yarns 141a and 142a are woven so as to meander up and down the parallel weft yarns 141b and 142b, and the vertical positions of the adjacent warp yarns 141a and 142a are reversed. A base tube 141 and a branch tube 142 are formed respectively.

  Since the tubular fabric base tube 141 and the branch tube 142 are mesh-shaped, air can be forcibly sucked from the entire length using the fabric fiber as a filter. It is possible to allow only excess water to pass through without passing through.

  One end of the base tube 141 is connected to the T-shaped joint 143, and the other end is connected to the suction pump 20 when placing the lining concrete 15 described later. One end of each of the two branch pipes 142 is connected to a T-shaped joint, and the other end (tip) is closed.

  The base tube 141 extends along the top of the inner surface of the waterproof sheet 12 laid in an arch shape, and in the illustrated example, the base tube 141 is spaced apart in the longitudinal direction so as to support the base tube 141 from below. The both ends of the seat wrap portion 144 provided in this manner are fixed to the inner surface of the waterproof sheet 12 by welding or bonding to the waterproof sheet 12.

  The branch pipes 142 and 142 correspond to joints between the lining concrete 15 ′ previously placed and the lining concrete 15 that is placed substantially in close contact with the T-type hose 14 having the branch pipe 142. The lining concrete 15 extends in an arc from the top to both shoulders along the inner surface of the waterproof sheet 12 at a position corresponding to one joint, and in the illustrated example, supports the branch pipe 142 from below. As described above, both end portions of the sheet wrap portion 144 provided at intervals in the longitudinal direction of the branch pipe 142 are fixed to the inner surface of the waterproof sheet 12 by welding or bonding to the waterproof sheet 12.

  On the inner side of the waterproof sheet 12, lining concrete 15 is placed substantially along the inner surface, and the base pipe 141, the branch pipe 142, and the T-type joint 143 of the T-type hose 14 are placed on the lining concrete 15. It is provided in the lining concrete 15 substantially closely. Note that the lining concrete 15 is successively provided by a predetermined unit length in the longitudinal direction of the tunnel, and a T-type hose 14 is installed on the inner surface of the waterproof sheet 12 corresponding to the lining concrete 15 having the predetermined unit length. And provided in the lining concrete 15.

  When constructing the tunnel structure of the present embodiment, it is performed according to the work procedure of FIG. 6. First, the waterproof sheet 12 is placed on the mount 31 and extended (S 1), the mount 31 is lifted, and the spray provided on the inner surface of the natural ground. The waterproof sheet 12 is extended and arranged close to the inner surface of the arch part 11 a of the concrete 11, and a formwork (not shown) that closes the space between the arch part 11 a and the waterproof sheet 12 is provided. The space on the back side of the sheet 12 is closed (S2). FIG. 4A shows a state in which the waterproof sheet 12 is placed on the gantry 31 and is stretched, and FIG. 4B shows a state in which the stretched waterproof sheet 12 is disposed close to the inner surface of the arch portion 11a of the shotcrete 11. Show.

  Furthermore, a filler is filled and placed in a closed space between the arch portion 11a on the back side of the waterproof sheet 12 and the waterproof sheet 12 (S3). As shown in FIG. The consolidated layer 13 formed by consolidation is fixed to the arch portion 11 a and the back surface of the waterproof sheet 12. After the filler is consolidated and the consolidated layer 13 is formed, the above-mentioned formwork is removed and the gantry 31 is lowered (S4).

  Then, the T-type hose 14 is arrange | positioned to the inner surface side of the waterproof sheet 12, and the sheet | seat wrap part 144 is welded and attached (S5, S6). In the arrangement and attachment of the T-type hose 14, the base tube 141 is extended along the top of the inner surface of the waterproof sheet 12 fixed by the consolidated layer 13 and laid in an arch shape, and the already-placed lining concrete 15 'And the branch pipes 142 and 142 along the inner surface of the waterproof sheet 12 from the top toward both shoulders at positions corresponding to joints between the T-hose 14 and the lining concrete 15 described later. It extends in an arc shape (see FIGS. 2 and 5A). And the sheet | seat wrap part 144 provided in the base tube 141 and the branch pipe 142 is fixed to the inner surface of the waterproof sheet 12 by welding to the waterproof sheet 12 or the like.

  After that, as shown in FIG. 5 (b), the mold 33 is arranged by supporting it with the gantry 32 so as to close the space for placing the lining concrete 15 on the inner surface side of the waterproof sheet 12, and the mold frame. The rear end opening of the base tube 141 of the T-type hose 14 is pulled out from a end plate (not shown) that closes the 33 end portion (S7), and the rear end opening of the base tube 141 is connected to the suction pump 20 (FIG. 2). reference).

  Then, the lining concrete 15 is placed in the mold 33, and the rear end of the base tube 141 from an arbitrary time point of the placement progress, such as a placement start time or a predetermined time when a certain amount of filling is performed from the placement start. The suction pump 20 is driven from the opening to forcibly suck air, and the air in the placement space is forcibly sucked through the minute hole extending over the entire length of the base tube 141 and the minute hole extending over the entire length of the branch pipe 142. The lining concrete 15 is laid (S8).

  At this time, by the forced suction of the air by the base tube 141 provided along the top of the waterproof sheet 12, the lining concrete 15 can be drawn near the top end portion in the tunnel longitudinal direction and reliably filled, Furthermore, the top end of the joint of the existing lining concrete 15 'that is prone to air accumulation due to forced suction of air by the branch pipe 142 provided in an arc shape from the top of the waterproof sheet 12 along both shoulders. In the vicinity of the portion, the lining concrete 15 can be drawn and filled reliably (see FIG. 5C).

  And the placement of the lining concrete 15 is stopped by checking the filling information from the T-type hose 14 (S9, S10). For example, when the lining concrete 15 is filled up to the position of the T-type hose 14, the water in the concrete is sucked by the T-type hose 14. When a component such as water comes out, or when a component such as water comes out from the rear end opening of the base tube 141, the lining concrete 15 is filled in the placing space above the tip of the branch pipe 142. When the elapsed time) elapses, it is determined that the lining concrete 15 is filled in the placement space, and the placement is stopped. At this time, although the base pipe 141 and the branch pipe 142 allow the excess water to pass through and suck through with fine holes, the suction of the concrete cement is prevented using the woven fibers as a filter.

  Alternatively, as confirmation of the filling information, the intake pressure of the T-type hose 14 is measured by the measuring unit of the suction pump 20 and the intake pressure is displayed in the placement space by displaying the intake pressure on the display unit of the suction pump 20 or the like. When reaching a predetermined atmospheric pressure indicating that the air has run out, it is determined that the lining concrete 15 is filled in the placement space, and the placement is stopped.

  When the placement of the lining concrete 15 is completed, as shown in FIG. 5 (c), the vicinity of the top end in the tunnel longitudinal direction or the top end of the joint with the already placed lining concrete 15 ′. Also in the vicinity, the lining concrete 15 is surely filled, the base tube 141 and the branch pipe 142 of the T-type hose 14 are provided in close contact with the lining concrete 15 and are substantially along the inner surface of the waterproof sheet 12. Thus, the lining concrete 15 is formed. Thereafter, the formwork 33 is removed by lowering the gantry 32 or the like, and the tunnel structure of FIG. 1 is completed.

According to the construction method of the tunnel structure of the above embodiment, the waterproof sheet 12 is fixed by the consolidated layer 13. Therefore, the T-hose 14 is fixed to the inner surface of the waterproof sheet 12 and air is forcibly sucked to cover the concrete. When placing 15, the waterproof sheet 12 is not pulled inward due to the reduced pressure, and the waterproof sheet 12 can be stretched and the stress state uniformity can be ensured. Further, both the void on the back side of the waterproof sheet 12 and the void on the inner surface near the top end of the waterproof sheet 12 are eliminated by the consolidation layer 13 and the lining concrete 15 that is cast while forcibly sucking air. It becomes possible. Therefore, it is possible to realize a waterproof effect that is excellent in certainty and durability. Furthermore, since it is possible to perform forced suction of air over the entire length of the T-type hose 14, the number of hoses generated in the work space in the tunnel can be reduced, construction management can be facilitated, and forced suction can be performed. The number of necessary suction pumps can be reduced to one, and the number of construction equipment and construction costs can be reduced.

  Moreover, it is possible to make the base pipe 141 and the branch pipe 142 by using a cylindrical fabric having the same configuration, and in this case, the manufacturing cost of the T-type hose 14 can be reduced. Moreover, only the excess water in air and concrete can be attracted | sucked, without drawing in earth and sand and a cement component, using the fiber of a cylindrical fabric as a filter.

[Modifications of Embodiment, etc.]
The invention disclosed in this specification is specified by changing these partial configurations to other configurations disclosed in this specification, in addition to the respective inventions and embodiments, to the extent applicable. Including those specified by adding other configurations disclosed in the present specification, or those obtained by deleting these partial configurations to the extent that partial effects can be obtained, The following modifications are also included.

  For example, in the above-described embodiment, the waterproof sheet 12 stretched on the arch part 11a of the shotcrete 11 of the primary lining material is disposed close to the arch part 11a and the back surface of the waterproof sheet 12 and the consolidated layer 13 is fixed. It is also possible to arrange the waterproof sheet 12 extended on the arch part 10a of the natural ground 10 close to the arch part 10a of the natural ground 10 and fix the consolidated layer 13 to the back surface of the waterproof sheet 12. is there. In addition to the shotcrete 11, an appropriate material that can be fixed to the consolidated layer 13 can be used as the primary lining material.

  Further, the base tube and the branch tube of the T-type hose are not limited to the base tube 141 and the branch tube 142 of the embodiment, and are appropriate within the scope of the present invention. The method of weaving is also appropriate within the scope of the present invention.

  Moreover, the structure which fixes the base tube 141 and the branch pipe 142 of the T-type hose 14 to the inner surface of the waterproof sheet 12 is provided so that the seat wrap portion 144 is supported from the lower side at a plurality of locations of the base tubes 141 and 142. The structure is not limited to the structure in which both end portions of the wrap portion 144 are fixed to the waterproof sheet 12, and for example, a structure in which the periphery of the top portion is bonded and fixed to the waterproof sheet 12 along the longitudinal direction of the base tubes 141 and 142. Is possible.

  INDUSTRIAL APPLICABILITY The present invention can be used, for example, in a tunnel constructed by placing lining concrete while forcing air inside a waterproof sheet, such as a drainage tunnel, a watertight tunnel, and the like.

DESCRIPTION OF SYMBOLS 1 ... Ground mountain 1a ... Wall surface 2 ... Supporting work 3 ... Shotcrete 4 ... Rock bolt 5 ... Waterproofing sheet 6 ... Covering concrete S1, S2 ... Air gap 10 ... Ground mountain 10a ... Arch part 11 ... Shotcrete 11a ... Arch part DESCRIPTION OF SYMBOLS 12 ... Waterproof sheet 13 ... Consolidation layer 14 ... T type hose 141 ... Base pipe 142 ... Branch pipe 141a, 142a ... Warp yarn 141b, 142b ... Weft yarn 143 ... T type joint 144 ... Sheet wrap part 15, 15 '... Covering concrete 20 ... Suction pump 31, 32 ... Mount 33 ... Formwork

Claims (2)

A step of expanding and arranging the waterproof sheet in the vicinity of the arch portion of the natural mountain or the arch portion of the primary lining material;
Filling a filler between the arch portion and the waterproof sheet, and fixing the solidified layer formed by the filler to the arch portion and the back surface of the waterproof sheet;
Using a T-type hose in which the base pipe and the branch pipe have air permeability, the base pipe is extended along the top of the inner surface of the waterproof sheet laid in an arch shape, and the existing lining concrete is The branch pipe is extended in an arc from the top to both shoulders along the inner surface of the waterproof sheet at a position corresponding to the joint, and the base tube and the branch pipe are fixed to the inner surface of the waterproof sheet. And a process of
The formwork is arranged so that the rear end opening of the base tube is pulled out from the end plate, and lining concrete is placed in the formwork, and air is passed from the rear end opening of the base pipe from an arbitrary point of the placement progress. The base pipe and the branch pipe are forcedly sucked and the lining concrete is placed while forcibly sucking air in the placement space by using the air-permeable material constituting the base pipe and the branch pipe as a filter. A step of forming the lining concrete so that the lining concrete is provided in close contact with the lining concrete and substantially along the inner surface of the waterproof sheet;
A method for constructing a tunnel structure, comprising: The T-type hose is
The base pipe and the branch pipe are connected via a T-shaped joint,
2. The method for constructing a tunnel structure according to claim 1, wherein each of the base pipe and the branch pipe is made of a tubular fabric having air permeability and water permeability .

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