JP2017089106A - Method to form pressure-resistant bearing ground body for pipe roof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method to form a pressure-resistant bearing ground body more readily when installing a connected pipe roof structure that integrally supports a load from a ground, the pressure-resistant bearing ground body having prescribed compressive strength.SOLUTION: A method to form a pressure-resistant bearing ground body 14 for a pipe roof 12 is for forming the pressure-resistant bearing ground body 14 having prescribed compressive strength. A connecting steel material 13 for connecting pipe roof materials 11, 11 has a closing member fitted to cover a discharge port of a discharging flow channel, the closing member not being removed by water pressure of boring water but being removed by injection pressure of a ground improvement material injected into the pressure-resistant bearing ground body 14. The method to form the pressure-resistant bearing ground body includes a step for having the connecting steel material 13 self-drilled while the closing member is fitted thereon, and a step for removing the closing member from the discharge port by injecting the ground improvement material and forming an improved ground using the ground improvement material.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for forming a pressure-resistant supporting ground body in a pipe roof, and in particular, a plurality of pipe roof materials embedded in the ground at the outer peripheral portion of a tunnel are connected to each other so that a load from the ground can be supported integrally. The present invention relates to a method for forming a pressure-resistant supporting ground body in a pipe roof used when providing a pipe roof connecting structure.

  When constructing a tunnel in the ground, the pipe roof construction method embeds a plurality of pipe roof materials made of steel pipes, etc. in the ground in the upper part of the constructed tunnel before excavating the ground. It is a well-known construction method that allows a tunnel excavation operation that is performed subsequently to be performed in a more stable state by forming a pipe roof that receives a load in advance.

  In addition, as a method for constructing a tunnel using a pipe roof material made of steel pipe, etc., a steel pipe (pipe roof material) which is a long material toward the extending direction of the tunnel on the ground of the outer peripheral portion of the upper arch portion of the tunnel After pushing a plurality of pipes at intervals in the circumferential direction, the ground is filled with cement-based solidification material and stirred so as to surround the outer periphery of the tunnel including the gap between the long materials, so that A construction method has been disclosed in which a tunnel can be constructed by excavating the ground inside the ground-improved portion while receiving a steel pipe that has been improved and pushed in (for example, Patent Document 1). In the tunnel construction method of Patent Document 1, it is possible to construct a tunnel by excavating the inside of the ground improvement portion while minimizing the loosening of the ground due to excavation by the arch effect of the ground improvement portion having an annular cross-sectional view. become.

Japanese Patent No. 5308116

  In the tunnel construction method of Patent Document 1, a steel pipe (perproof material) is pushed into the ground at the outer peripheral portion of the tunnel, and then the ground is improved in an annular shape in cross section by surrounding the outer periphery of the tunnel. After pushing the propulsion pipe with the widening improvement device connected to the tip of the shaft toward the extending direction of the tunnel from both or one of the shafts into the ground with the specified extension, improve the ground from the tip of the widening improvement device. The ground improvement part is formed by repeating the work of gradually pulling out the propelling pipe while discharging the material and stirring it with the surrounding earth and sand.

  Then, in the tunnel construction method of Patent Document 1, the ground improvement portion is arranged around the ground at the outer peripheral portion of the tunnel so as to have an annular shape in cross section so that a desired arch effect can be obtained by the formed ground improvement portion. Since it is necessary to continuously form the gaps in the direction without any gaps, the operation of pushing in and pulling out the propelling pipe having the widening improving device connected to the tip must be repeated many times. For this reason, a large amount of ground improvement material is required, and the construction cost increases. In particular, when the tunnel construction extension is long, it is difficult to push the propelling pipe with high accuracy. Therefore, in order to make the ground improvement part continuous without gaps in a sectional view, the ground improvement part is formed in a wider range. This creates a need and further increases construction costs.

  Further, in the tunnel construction method disclosed in Patent Document 1, a plurality of steel pipes (pipe roof materials) pushed into the ground at the outer peripheral portion of the tunnel function as leading support works in the tunnel extending direction due to their large rigidity. When excavating the ground, it is possible to improve the stability of the natural ground and suppress the deformation of the natural ground, but multiple pipe roof materials are used in the transverse direction (cross-sectional direction) of the tunnel. Are embedded in a state of being divided individually, it is difficult for these pipe roof materials to function as a support in the transverse direction to exert an arch effect.

  In contrast, the applicant of the present application previously described in Japanese Patent Application No. 2015-57878, the ends of both sides are fixed to each pair of pipe roof materials adjacent to each other in the direction along the arc-shaped cross section, and the connection connecting steel material. By connecting these pipe roof materials to each other and improving the ground at the space between adjacent pairs of pipe roof materials to form a pressure-resistant supporting ground body having a predetermined compressive strength, a plurality of pipe roofs Multiple pipe roof materials embedded in the ground that support the work in the transverse direction of the tunnel that can demonstrate the arch effect by connecting the materials together and supporting the load from the ground as a unit And a pipe roof connection structure that can be formed on the outer periphery of the tunnel by a simple construction method while suppressing the amount of ground improvement material used However, in addition to this, when providing such a pipe roof connection structure, a pressure-resistant support ground body having a predetermined compressive strength is formed by ground improvement in the interval portion between each pair of adjacent pipe roof materials. Development of a construction method that can be carried out more easily is desired.

  In the present invention, when providing a pipe roof connection structure that connects a plurality of pipe roof materials to each other and supports a load from the ground as one body, the ground of the gap portion between each pair of adjacent pipe roof materials is more It aims at providing the formation method of the pressure | voltage resistant support ground body in a pipe roof which can improve the ground by a simple construction method, and can form the pressure | voltage resistant ground body which has predetermined | prescribed compressive strength.

  The present invention relates to a plurality of pipe roofs that extend in the tunnel extending direction and are arranged side by side in the direction along the arc-shaped cross section in the ground of the outer peripheral portion of the tunnel constructed in the ground. By connecting the materials to each other and providing a pipe roof connection structure that can support the load from the ground as a unit, by improving the ground in the space between adjacent pairs of pipe roof materials A method for forming a pressure-resistant support ground body in a pipe roof that forms a pressure-resistant support ground body using an improved ground having a predetermined compressive strength, wherein the pipe roof connection structure is adjacent in a direction along the arc-shaped cross section. Each pair of pipe roof materials is secured to the ends on both sides and connected to each other to connect the pipe roof materials to each other, and each pair of adjacent pipe roofs Including a pressure-resistant supporting ground body provided in a space portion, and the connection connecting steel material includes a fluid supply path provided penetrating in the axial direction, and the fluid. A plurality of discharge passages extending outward from the supply passage and having discharge ports opened on the outer peripheral surface are provided at a plurality of positions at intervals in the axial direction. From the adjacent one of the pipe roof materials, the closure member attached with the joining strength that is removed by the injection pressure when injecting the ground improvement agent is attached so as to cover each of the discharge ports. A step of self-drilling the connection connecting steel material toward the other pipe roof material, and then closing one end portion of the fluid supply path and injecting improved ground material from the other end portion. The occlusion Removing the material from the discharge port, and spreading the ground improvement material over the ground between the adjacent pair of pipe roof materials to form the improved ground, and forming a pressure-resistant support ground body in the pipe roof. By providing this, the above-mentioned object is achieved.

  And the formation method of the pressure | voltage resistant support ground body in the pipe roof of this invention is the water pressure of the drilling water supplied at the time of drilling is 0.2-0.3 MPa, The injection pressure at the time of inject | pouring a ground improvement material, It is preferably 0.5 to 3.0 MPa.

  Moreover, it is preferable that the formation method of the pressure | voltage resistant support ground body in the pipe roof of this invention is a vinyl tape with which the said closure member covered each said discharge outlet and was wound around the outer peripheral surface of the said connection connection steel material.

  Further, according to the method of forming a pressure-resistant supporting ground body in a pipe roof of the present invention, the connecting and connecting steel material is made of a steel rod having male threaded ridges formed at least at both end portions, and is a fastening member provided inside the pipe roof material. It is preferable to fix to the pipe roof material by fastening the ends on both sides to the platform.

  Furthermore, in the method for forming a pressure-resistant supporting ground body in a pipe roof according to the present invention, it is preferable that the pipe roof material has a circular hollow cross-sectional shape.

  Further, in the method for forming a pressure-resistant support ground body in a pipe roof according to the present invention, the plurality of pipe roof materials are spaced in a direction along the arc-shaped cross section in the ground at least in the upper part of the tunnel constructed in the ground. It is preferable that they are buried side by side.

  Further, according to the method of forming a pressure-resistant supporting ground body in a pipe roof according to the present invention, the plurality of pipe roof materials follow a circular cross section including the arc-shaped cross section in the ground of the outer peripheral portion of the tunnel constructed in the ground. In the circumferential direction, it is preferable that they are buried side by side over the entire circumference at intervals.

  According to the pressure roof supporting ground body forming method for a pipe roof of the present invention, when a plurality of pipe roof materials are connected to each other to provide a pipe roof connecting structure that integrally supports a load from the ground, By improving the ground at the space between the pair of pipe roof members, it is possible to more easily form a pressure-resistant supporting ground body using the improved ground having a predetermined compressive strength.

It is a schematic sectional drawing explaining the connection structure of the pipe roof formed by employ | adopting the formation method of the pressure | voltage resistant support ground body which concerns on preferable one Embodiment of this invention. It is a schematic sectional drawing explaining the tunnel constructed | assembled by the construction method of the tunnel which employ | adopted the formation method of the pressure | voltage resistant support ground body which concerns on preferable one Embodiment of this invention. It is a schematic perspective view explaining the chemical | medical solution injection | pouring process of the construction method of a tunnel. It is a schematic perspective view explaining the underground pit construction process of the construction method of a tunnel. The tunnel construction method of the tunnel construction method will be described. (A) is a schematic cross-sectional view, and (b) is a schematic cross-sectional view. It is a schematic perspective view explaining the circumference shield construction process of the construction method of a tunnel. (A)-(c) is the schematic cross-sectional view explaining the circumferential shield construction process of the construction method of a tunnel. It is a schematic perspective view explaining the pipe roof construction process of the construction method of a tunnel. It is a schematic cross section explaining the pipe roof construction process of the construction method of a tunnel. The connection connection steel material used in the formation method of the pressure | voltage resistant support ground body which concerns on preferable one Embodiment of this invention is demonstrated, (a) is a top view, (b) is a longitudinal cross-sectional view along AA of (a). (C) is a cross-sectional view along BB of (a), (d) is a top view of the state in which the vinyl tape was attached. It is a schematic perspective view explaining the buttocks construction process of the construction method of the tunnel. The buttock construction process of the tunnel construction method will be described. (A) is a schematic cross-sectional view and (b) is a schematic cross-sectional view. It is a schematic longitudinal cross-sectional view explaining the excavation and lining process of the construction method of a tunnel. It is a schematic cross section explaining the excavation and lining process of the construction method of a tunnel. (A)-(j) is the schematic cross-sectional view explaining the excavation and lining process of the construction method of a tunnel. It is a schematic longitudinal cross-sectional view of the heel part explaining the excavation and lining process of the construction method of a tunnel.

  The method for forming the pressure-resistant supporting ground body 14 (see FIG. 1) in the pipe roof according to a preferred embodiment of the present invention is, for example, in a deep underground where a section ground right of a depth of 40 m or more from the ground surface is unnecessary, for example, a road A large cross section as shown in FIG. 2 having a diameter of, for example, about 29 m, which can enclose the main tunnel 51 and the lamp tunnel 52, which connects the main tunnel 51 (see FIG. 2) and the lamp tunnel 52. This is employed when the pipe roof connection structure 10 is formed in the pipe roof construction process to be described later in the tunnel construction method for constructing the widening tunnel 50 for interchange. That is, in the method for forming the pressure-resistant support ground body 14 of the present embodiment, the pipe roof construction process (FIGS. 8 and 9) described later is performed prior to the excavation and lining process (see FIG. 13) for excavating the ground of the widening tunnel 50. The pipe roof connecting structure 10 (see FIG. 1) for connecting the plurality of pipe roof materials 11 embedded in the ground of the outer peripheral portion of the widening tunnel 50 to each other and integrally supporting the load from the ground. When providing, the ground of the space | interval part of each pair of adjacent pipe roof materials 11 improves the ground, and it enables it to form the pressure-resistant support ground body 14 by the improved ground which has predetermined | prescribed compressive strength more easily. It was adopted as a method.

  In the present embodiment, the tunnel construction method for constructing the widening tunnel 50 is preferably performed from the main tunnel 51 after the main tunnel 51 having a diameter of, for example, about 16 m is formed in the ground by a shield method. Then, the underground shaft 20 is formed at both ends of the construction section of the widening tunnel 50 (see FIG. 4 and FIGS. 5A and 5B), and the circumferential shield tunnel described later is passed through the underground shaft 20. 30 (refer to FIG. 6, FIG. 7 (a) to (c)), pipe roof 12 (refer to FIG. 8, FIG. 9), and buttocks ground improvement body 40 (refer to FIG. 11, FIG. 12) come to be performed. ing.

  That is, in this embodiment, the tunnel construction method for constructing the widening tunnel 50 is a method of constructing the widening tunnel 50 by injecting a chemical solution from the main tunnel 51 as shown in FIGS. At the ends of both sides of the construction section of the widening tunnel 50, the underground shaft 20 is constructed from the main tunnel 51 toward the lower ground at the chemical injection process (see FIG. 3) for stabilizing the ground and the surrounding ground. The shaft construction process (see FIGS. 4 and 5 (a), (b)), and the circumferential shield machine 31 is started from the underground shaft 20, and the circumferential shield machine 31 is made to reach the underground shaft 20 In addition, the circumferential shield construction process (see FIGS. 6 and 7A to 7C) for forming the circumferential shield mine 30 as the working mine when the pipe roof 12 and the buttock ground improvement body 40 are constructed. And by pushing a plurality of pipe roof materials 11 into the ground from the circumferential shield mine 30 at one end of the construction section of the widening tunnel 50 toward the circumferential shield mine 30 at the other end. A pipe roof construction step (see FIGS. 8 and 9) for forming a cylindrical pipe roof 12 in which a plurality of pipe roof materials 11 are arranged side by side in the circumferential direction, and the inside of each circumferential shield mine 30 By improving the ground of the other side, the heel part improvement body forming step for forming the heel part ground improvement body 40 at each end of the construction section of the widening tunnel 50 (FIG. 11, FIG. 12 (a), (b )), And the inner region surrounded by the cylindrical pipe roof 12 and the circumferential shield mine 30 and the buttock ground improvement body 40 at both ends is excavated from the upper part to the lower part. And by drilling Excavation and lining process for covering the inner wall surface of the pipe roof 12 and the inner wall surface of the buttock ground improvement body 40 and forming the lining walls 43a and 43b sequentially from the upper part to the lower part (see FIGS. 13 to 16) ) And.

  In the chemical injection process in the tunnel construction method described above, as shown in FIG. 3, a known chemical injection pipe 26 is connected from the main tunnel 51 to the ground of the outer peripheral portion thereof in the circumferential direction and the axial direction of the main tunnel 51. A large number of lines are inserted at predetermined intervals. Further, by injecting a known chemical solution such as a water glass system through the inserted chemical solution injection pipe 26, the ground in the region where the widening tunnel 50 (see FIG. 2) is constructed and the surrounding ground are improved. And stabilize these grounds. In the chemical injection process, the number of chemical injection pipes 26 inserted, the type and amount of the chemical to be injected, the injection pressure, the gel time, etc., include the type of target ground, groundwater level, hydraulic conductivity, particle size distribution, improvement range, etc. In view of this, it is possible to design appropriately.

  In the present embodiment, prior to performing each process for constructing the widening tunnel 50, the steel reinforcing ring 27a is formed along the inner peripheral surface of the segment constituting the outer portion of the main tunnel 51, for example. It is preferable to reinforce the main tunnel 51 by forming a segment reinforcement support 27 by installing a plurality of the main tunnel 51 in the axial direction at a predetermined interval. In particular, the segment reinforcement support 27 includes the end of both sides of the construction section of the widening tunnel 50 where the underground shaft 20 and the anchorage ground improvement body 40 are formed, and the axis of the main tunnel 51 across the ends. It is preferable to install in a portion adjacent to the direction.

  In the shaft construction process, as shown in FIG. 4 and FIGS. 5A and 5B, a plurality of steel rectangles having a rectangular cross section, for example, from both ends of the construction section of the widening tunnel 50 in the main tunnel 51. The propulsion pipe 21 is propelled vertically downward by a known closed vertical propulsion method, and a plurality of these rectangular propulsion pipes 21 are arranged side by side adjacent to each other in the vertical and horizontal directions, and has a substantially hexahedral shape as a whole. A steel lining body 23 to be 20 is formed.

  That is, in the vertical shaft building process, a known rectangular excavator 22 having a rectangular cross section is attached to the lower end portion of the rectangular propelling pipe 21, and the rectangular propelling pipe 21 is continuously connected to the rectangular excavating machine 22 while digging downward. By installing and pushing downward, the rectangular propulsion pipe 21 is installed from the main tunnel 51 vertically downward to a predetermined depth. The operation of installing the rectangular propulsion pipes 21 to a predetermined depth in this way is repeated a plurality of times while adjoining the vertical propulsion pipes 21 vertically and horizontally, so that the rectangular propulsion pipes 21 are integrated into a rectangular shape in plan view. For example, the hexagonal steel cover having a length of about 15 to 18 m in the axial direction of the main tunnel 51, a length of about 8 to 10 m in the width direction, and a depth of about 18 m in the vertical direction. The work body 23 is constructed on the ground below the main line tunnel 51. After that, in the constructed steel lining body 23, the partition walls 23b formed by the respective rectangular propulsion pipes 21 are arranged in a grid in the vertical and horizontal directions by partitioning the inner region surrounded by the four sides by the portion that becomes the outer peripheral wall 23a. Cut and remove the part. Thereby, the partition wall 23b is removed from the underground pit 20 that has secured a work space of a considerable size with the plurality of rectangular excavators 22 left in the ground (see FIGS. 7A to 7C). After being surrounded by the outer peripheral wall 23a of the steel lining body 23, the steel lining body 23 is constructed at both ends of the construction section of the widening tunnel 50, respectively. The built underground pit 20 is used as a starting mine and a reaching mine of the circumferential shield machine 31 in the circumferential shield construction process.

  In the circumferential shield construction process, as shown in FIG. 6 and FIGS. 7A to 7C, a known circumferential shield machine 31 was started and started from each built shaft 20. By causing the circumferential shield machine 31 to reach the same underground shaft 20, the circumferential shield tunnel 30, which is the work tunnel when constructing the pipe roof 12 and the buttock ground improvement body 40, is installed in the construction section of the widening tunnel 50. Each is formed at both ends.

  In the present embodiment, the circumferential shield machine 31 is a known shield machine having a rectangular cross section with a shield height of, for example, about 3 to 4.5 m, and preferably having a muddy water type curvature. The circumferential shield machine 31 receives a driving force from a main push jack 33 (see FIG. 7B) installed in the underground shaft 20, and has a rectangular section and a curved portion lining segment 32 that can be curved. Can be excavated along the circumference of the diameter that is slightly larger than the outer diameter of the widening tunnel 50 until reaching the underground shaft 20. Thereby, the circumferential shield mine 30 extending in an annular shape by the curved line lining segment 33 is widened along a circular cross section in which the pipe roof 12 is formed in a cylindrical shape in the pipe roof construction process described later. It will be provided at both ends of the construction section of the tunnel 50 respectively.

  In the pipe roof construction process, as shown in FIGS. 8 and 9, the circumferential shield mine provided at the other end from the circumferential shield mine 30 provided at one end of the construction section of the widening tunnel 50. Toward 30, a plurality of pipe roof materials 11 are pushed into the ground while being excavated by a known pipe roof excavation method. As a result, a cylindrical pipe roof 12 is formed, which is configured by burying the plurality of pipe roof materials 11 side by side in the circumferential direction.

  That is, in this embodiment, a muddy water type propulsion method that can be constructed even under high water pressure is adopted as the pipe roof excavation method, and the pipe roof material 11 has a size that allows an operator to work inside, for example, about φ2.0 m. By using these steel pipes, the plurality of pipe roof materials 11 are pushed into the ground, so that the plurality of pipe roof materials 11 are placed in the ground in the outer peripheral portion of the widening tunnel 50 constructed in the ground. Each is buried in the extending direction. In addition, the pipe roof material 11 is pushed into the ground from the circumferential shield mine 30 by the pipe roof excavation method, and the work is constructed in the ground by repeating a plurality of times at a predetermined pitch in the circumferential direction of the circumferential shield mine 30. A plurality of pipe roof materials 11 may be embedded in the ground of the outer peripheral portion of the widening tunnel 50 in a circumferential direction along a circular cross section including an arcuate cross section with a predetermined interval. It becomes possible. Further, by this, a cylindrical shape that receives a load from the surrounding ground in advance when excavating the widening tunnel 50 by a plurality of pipe roof members 11 embedded in a circumferential direction along a circular cross section including an arc-shaped cross section. The pipe roof 12 can be formed.

  And in this embodiment, in the above-mentioned pipe roof construction process, a plurality of pipe roof materials 11 embed | buried in the earth along the circular cross section containing an arc-shaped cross section are connected integrally by the connection structure 10 of a pipe roof. By doing so, it becomes possible to form the cylindrical pipe roof 12 capable of exhibiting the arch effect. As a result, the support in the transverse direction that supports the load in the transverse direction (cross-sectional direction) of the widening tunnel 50 is efficiently applied to the ground of the outer peripheral portion of the widening tunnel 50 by the pipe roof 12 using the plurality of pipe roof materials 11. It becomes possible to provide.

  That is, in this embodiment, the pipe roof connection structure 10 extends in the extending direction of the widening tunnel 50 on the ground of the outer peripheral portion of the widening tunnel 50 constructed in the ground, as shown in FIGS. And connecting a plurality of pipe roof materials 11 embedded in a line along the arc-shaped cross section (circular cross section including the arc-shaped cross section in this embodiment) at intervals, from the ground As shown in FIG. 1, the ends of both sides are fixed to each pair of pipe roof members 11 adjacent to each other in the direction along the arcuate cross section. The connecting roof steel material 13 for connecting these pipe roof materials 11 to each other, and a pressure-resistant supporting ground body 14 provided between the adjacent pair of pipe roof materials 11. Have

  In the present embodiment, the plurality of pipe roof members 11 connected by the pipe roof connecting structure 10 are arranged in a direction along the arc-shaped cross section in the ground at least in the upper portion of the widening tunnel 50 constructed in the ground. In this embodiment, in particular, in the ground of the outer peripheral portion of the widening tunnel 50 constructed in the ground, a circle along a circular cross section including an arc-shaped cross section is embedded. In the circumferential direction, they are embedded side by side over the entire circumference (see FIG. 9).

  Further, in the present embodiment, the connecting and connecting steel material 13 constituting the pipe roof connecting structure 10 has a diameter of the above-mentioned arc-shaped cross section in the interval portion between each pair of adjacent pipe roof materials 11 as shown in FIG. It is attached to the inner part and the outer part of the direction in two steps, and the pressure-resistant support ground body 14 is provided including a region sandwiched between a pair of connection connecting steel members 13 arranged in these two steps. A plurality of the connecting and connecting steel members 13 arranged in two stages are attached in the extending direction of the pipe roof member 11 at a pitch of 30 to 100 cm. As the connecting and connecting steel material 13 is attached at a pitch of 30 to 100 cm in the extending direction of the pipe roof material 11, as a tensile material for firmly connecting each pair of adjacent pipe roof materials 11 and 11, In addition to being able to function effectively, it is possible to more effectively restrain the pressure-resistant support ground body 14 provided in the space between the pair of adjacent pipe roof members 11 and 11.

  In the present embodiment, the pipe roof connection structure 10 can be easily formed by work from the inside of the pipe roof material 11. That is, in this embodiment, the pipe roof material 11 is made of, for example, a steel pipe having a size of about φ2.0 m, and an operator can enter and work, and the connection connecting steel material 13 and the pressure-resistant support. Various materials and equipment necessary for constructing the ground body 14 can be carried into the pipe roof material 11.

  As shown in FIGS. 10 (a) and 10 (b), the connection connecting steel material 13 constituting the pipe roof connection structure 10 of the present embodiment is a hollow including a fluid supply path 13a provided penetrating in the axial direction. It is formed from a steel rod or the like, and in this embodiment, it is preferably formed by a hollow lock bolt. Further, as shown in FIG. 10 (c), the connection connecting steel material 13 includes a discharge flow path 13 b that extends outward from the fluid supply path 13 a and opens the discharge port 13 e on the outer peripheral surface of the connection connection steel material 13. It is provided in several places at intervals in the axial direction. In the present embodiment, the plurality of discharge channels 13b are preferably formed in four directions in the radial direction, and the liquid or the like flowing through the discharge channel 13b is discharged from the discharge port 13e in four directions. It has become.

  In the present embodiment, the connecting and connecting steel material 13 is formed to have a length of, for example, about 1000 mm as a length that can be disposed across each pair of adjacent pipe roof materials 11 and 11. The discharge flow paths 13b formed at a plurality of places are formed at a plurality of places at a pitch of, for example, about 100 to 300 mm in the length direction. In the present embodiment, the connecting and connecting steel material 13 is formed with a thickness of, for example, about φ30 mm, and the fluid supply path 13a is formed with an inner diameter of, for example, about φ15 mm, The discharge port 13e is formed to have an inner diameter of about φ8 mm, for example.

  Moreover, in this embodiment, the connection connection steel material 13 is formed with a rope screw (11/4 "rope) of about R32 mm, for example, over its entire length, thereby at least both end portions (in this embodiment, A male threaded ridge 13f is formed over the entire length of the male threaded ridge 13f on both ends of the fastening thread 16 provided inside the pipe roof material 11 using a nut member 15. By fastening each of them, the connection connecting steel material 13 can be fixed to the pipe roof material 11. Further, it is sealed to one end portion of the connection connection steel material 13 via the male screw protrusion 13f. By tightening a cap member (not shown) for use, the improved ground material is pumped from the opening at the other end while the opening at the one end of the fluid supply path 13a is closed. Ground material From the discharge port 13e of the discharge passage 13b by injection toward the ground surrounding, so that can be injected.

  Furthermore, in this embodiment, as shown in FIG.10 (d), as the closure member 17 which covers the discharge outlet 13e, a vinyl tape is wound around the outer peripheral surface covering the discharge outlet 13e in the connection connection steel material 13. Yes. The vinyl tape 17 does not come off due to the water pressure of the drilling water supplied when the continuously connecting steel material 13 is drilled (during self-drilling), and has a bonding strength that is released by the supply pressure when the ground improvement material is injected. 13e is wound around the outer peripheral surface of the connection connecting steel material 13. That is, the vinyl tape 17 which is the closing member 17 is connected to the steel while cutting the ground from one adjacent pipe roof 11 to the other pipe roof 11 with a cutting bit (not shown) attached to the tip. As the water pressure of the drilling water supplied at the time of drilling by drilling the ground between these by self-drilling 13, for example, the injection pressure at the time of injecting the ground improvement material does not deviate at a water pressure of 0.2 to 0.3 MPa. As, for example, it is wound around the outer peripheral surface of the connection connecting steel material 13 so as to cover each discharge port 13e with a joining strength that is released by an injection pressure of 0.5 to 3.0 MPa.

  And in this embodiment, it attached to the connection connection steel material 12 with the joining strength which does not come off by the injection | pouring pressure at the time of inject | pouring a ground improvement material, as above-mentioned by the water pressure of the drilling water supplied at the time of drilling. A step in which the connecting and connecting steel material 12 is perforated and installed from one adjacent pipe roof material 11 to the other pipe roof material 11 in a state where the vinyl tape 17 is attached so as to cover each discharge port 13e; After that, by closing the opening at one end of the fluid supply path 13a and injecting the ground improvement material from the opening at the other end, the vinyl tape 17 is removed from the discharge port 13e by the injection pressure, A method of forming a pressure-resistant supporting ground body including a step of forming the improved ground by spreading the ground improving material over the ground in the space between adjacent pipe roof materials 11 Te, the ground between each pair of pipes roof member 11 adjacent constituting the pipe the roof 12, it is possible to withstand supporting ground member 14 is easily formed.

  Moreover, according to this, according to the formation method of the pressure | voltage resistant support ground body in the pipe roof of this embodiment, the connection structure 10 of the pipe roof which connects the some pipe roof material 11 mutually and supports the load from a ground integrally. When providing, the ground of the space | interval part of each pair of adjacent pipe roof materials 11 improves the ground, and it becomes possible to form more easily the pressure | voltage resistant support ground body 14 by the improved ground which has predetermined | prescribed compressive strength. .

In addition, the pressure | voltage resistant support ground body 14 formed by the formation method of the pressure | voltage resistant support ground body of this embodiment is the space | interval part of each pair of adjacent pipe roof materials 11 in the some pipe roof material 11 embed | buried in the ground. It can be handled as a padded ground body that functions as a compression material provided in between. After the cylindrical pipe roof 12 made of a plurality of pipe roof materials 11 is formed in the ground, the pressure-resistant supporting ground body 14 is excavated inside and receives a load from the surrounding ground. When exerting the arch effect, the compressive force generated at the space between the pair of adjacent pipe roof members 11 along the circumferential direction of the pipe roof 12 is, for example, 2 N / It is formed so as to have a compressive strength of about mm ² .

  In addition, as described above, the operation of connecting each pair of adjacent pipe roof members 11 together by the pipe roof connecting structure 10 is sequentially pushed into the ground at intervals in the circumferential direction in the pipe roof construction process. Among the plurality of pipe roof materials 11, when some of the pipe roof materials 11 are embedded in advance, the subsequent pipe roof material 11 is transferred from one circumferential shield well 30 to the other circumferential shield. It can be carried out simultaneously with or in parallel with the work of sequentially pushing into the ground toward the pit 30. Moreover, the operation | work which connects each pair of adjacent pipe roof material 11 integrally by the connection structure 10 of the pipe roof of this embodiment is implemented simultaneously or in parallel with the collar part improvement body formation process constructed | assembled subsequently. You can also By these, it becomes possible to suppress effectively that a construction period will be delayed.

  In the above-mentioned tunnel construction method in the tunnel construction method, as shown in FIGS. 11 and 12 (a) and 12 (b), by improving the ground inside each circumferential shield mine 30, the ground is improved. The buttocks ground improvement body 40 is formed at both ends of the construction section of the widening tunnel 50. That is, in the heel part improvement body formation process, by the operation | work from the inside of each circumferential shield mine 30 in the edge part of the both sides of the construction area of the widening tunnel 50, or the inside of the pipe roof material 11 of the part adjacent to this. For example, from the upper part to the lower part of each circumferential shield mine 30, by using the known ground improvement device 42, preferably by improving the ground by a high-pressure jet stirring method, the cylindrical unit improvement body 41 is It is formed in the ground in the radial direction surrounded by the circumferential shield pit 30. Further, by repeating the ground improvement by such a high-pressure jet agitation method a plurality of times on the inner ground of the circumferential shield mine 30, a plurality of cylindrical unit improvement bodies 41 superimpose their outer peripheral portions. However, the buttocks ground improvement body 40 (see FIGS. 12A and 12B) formed integrally by being arranged side by side in the vertical and horizontal directions is arranged at the ends on both sides of the construction section of the widening tunnel 50. The gap between the shield mine 30 and the main tunnel 51 is closed so that it is constructed inside each circumferential shield mine 30.

  As a result, the excavation area of the construction section of the widening tunnel 50 is surrounded by the pipe roof 12 formed in a cylindrical shape, the circumferential shield mine 30 and the buttock ground improvement body 40 at both ends. Therefore, in the excavation and lining process, these inner regions are excavated in a stable state while the pipe roof 12 and the buttock ground improvement body 40 support the load from the outer ground. It becomes possible.

  In the excavation and lining process, as shown in FIG. 13 to FIG. 16, the periphery is surrounded by the pipe roof 12 formed in a cylindrical shape, the circumferential shield mine 30 and the buttock ground improvement body 40 at both ends. The inner region is excavated from the upper part to the lower part, covers the inner wall surface of the pipe roof 12 exposed by excavation and the inner wall surface of the buttock ground improvement body 40, and is directed from the upper part to the lower part by a so-called reverse winding method. The lining walls 43a and 43b are sequentially formed.

  That is, in the excavation and lining process, for example, a backhoe or a bulldozer is used as the excavating machine 44, and the excavation work of the widening tunnel 50 is sequentially performed from the upper part to the lower part of the excavation area inside the pipe roof 12, Covering the inner wall surface of the pipe roof 12 exposed by excavation and the inner wall surface of the buttocks ground improvement body 40 from the upper step portion toward the lower step portion, for example, a lining wall 43a ( 15) and the lining wall 43b (see FIG. 16) of the buttocks are sequentially constructed. The lining walls 43a and 43b are formed sequentially by a so-called forward winding method from the lower part to the upper part after excavating the entire excavation section of the inner region surrounded by the buttock ground improvement body 40. You can also go.

  Here, in the excavation work of the widening tunnel 50, the stability of the natural ground is improved by the function as a receiving support work in the extending direction of the tunnel due to the large rigidity of the pipe roof material 11 constituting the pipe roof 12. Thus, excavation work can be performed more efficiently in the tunnel extending direction while suppressing deformation of the natural ground. Moreover, in this embodiment, since each pair of adjacent pipe roof materials 11 are integrally connected by the pipe roof connection structure 10, the pipe roof 12 functions as a support in the transverse direction (cross-sectional direction) of the tunnel. It becomes possible to make it. As a result, for example, the number of support works and design strength installed inside the cylindrical pipe roof 12 along with the excavation work of the widening tunnel 50 can be reduced, or the support work can be omitted. .

  In excavation work on the upper stage of the widening tunnel 50, a sediment discharge pipe 53 (see FIG. 13) from the work space to the main tunnel 51 is installed by, for example, steel pipe propulsion from the main tunnel 51, and the sediment discharge pipe 53 By inserting the excavated earth and sand, the excavated earth and sand can be carried out through the main tunnel 51. The main tunnel 51 exposed as the excavation work progresses from the upper part to the lower part of the excavation area can be crushed using, for example, a crushing machine and removed together with excavated earth and sand (see FIG. 15).

  Moreover, in the operation | work which constructs the lining wall 43a of a cylindrical part, the waterstop iron plate 46 is welded etc. so that it may straddle the inner surface of each pair of adjacent pipe roof materials 11 of the pipe roof 12 exposed by excavation, for example. Is attached, and the backside filling material 47 is filled on the back side of the water-stopping iron plate 46 and solidified (see FIG. 1). After that, an SRC (steel reinforced concrete) structure is constructed by assembling a steel frame, a reinforcing bar, a formwork, and the like on the inner side of the water-stopping iron plate 46, and placing concrete, so that the so-called reverse winding method is applied from the upper stage to the lower stage. It becomes possible to construct the lining wall 43a of the cylindrical part by RC or reinforced concrete (RC) structure.

  Further, in the operation of constructing the lining wall 43b of the buttock, for example, spray concrete 48 is preferably sprayed on the inner wall surface of the buttock ground improvement body 40 exposed by excavation, for example, toward the heel part ground improvement body 40. The inner wall surface is reinforced by driving a plurality of lock bolts 49 (see FIG. 16). After that, by covering the inner surface of the reinforced buttock ground improvement body 40 and further attaching a waterproof sheet, by assembling a steel frame, reinforcing bar, formwork, etc. on the inner part of this, and placing concrete By the so-called reverse winding method, it is possible to construct the lining wall 43b of the heel portion with an SRC (steel reinforced concrete) structure or an RC (steel reinforced concrete) structure from the upper step portion toward the lower step portion.

  Thus, a wide-width widening tunnel 50 (FIG. 2) for connecting the main tunnel 51 and the lamp tunnel 52, which is surrounded by the cylindrical lining wall 43a and the lining walls 43b on both sides. Can be built in deep underground where no separate ground rights are required. Further, by connecting the ramp tunnel 52 to the constructed widening tunnel 50 and constructing the main body structure of the interchange, for example, an interchange for connecting the main tunnel 51 for the road and the ramp tunnel 52 is replaced with the widening tunnel. 50 can be provided inside.

  And according to this embodiment, the crossing direction support of the tunnel which can exhibit the arch effect by the several pipe roof material 11 embed | buried under the ground by the connection structure 10 of the pipe roof provided with the above-mentioned structure. The work can be efficiently formed on the ground of the outer peripheral portion of the widening tunnel 50 by a simple construction method while suppressing the amount of ground improvement material used.

  That is, according to the pipe roof connecting structure 10 having the above-described configuration, the end portions 13a on both sides are fixed to the pair of pipe roof materials 11 adjacent to each other in the direction along the arc-shaped cross section, and these pipes are connected. Since it is comprised including the connection connecting steel material 13 which connects the roof material 11 mutually, and the pressure | voltage resistant support ground body 14 provided in the space | interval part of each pair of adjacent pipe roof materials 11, it is comprised. And a pair of pipe roof materials adjacent to each other by a synergistic effect of the connection connecting steel material 13 that functions as a pressure-resistant support ground body 14 and the pressure-resistant support ground body 14 that functions as a compression material and has a desired compressive strength. It is possible to cause the pipe roof 12 to exhibit the arch effect due to the continuation of the arcs 11 as an integral unit in a stable state. As a result, the support work in the transverse direction of the widening tunnel 50 that supports the load from the surrounding ground is efficiently and strongly strengthened by the cylindrical pipe roof 12 in which the plurality of pipe roof materials 11 are integrated in the circumferential direction. Can be formed. In addition, since the pressure-resistant support ground body 14 having a desired compressive strength may be provided only in the interval portion between each pair of adjacent pipe roof materials 11, the amount of ground improvement material used can be suppressed or made unnecessary. By a simple construction method, it is possible to efficiently form a support in the transverse direction on the ground of the outer peripheral portion of the widening tunnel 50.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, a pipe roof using a pipe roof connecting structure formed by adopting the method for forming a pressure-resistant supporting ground body of the present invention is not necessarily provided on the ground of the outer peripheral portion of a tunnel constructed in a deep underground. Alternatively, it may be provided on a ground constructed in a tunnel constructed in a shallow portion of the ground or an outer peripheral portion of an underground structure other than the tunnel. In addition, the plurality of pipe roof materials constituting the pipe roof do not necessarily have to be embedded in the circumferential direction along the circular cross section at intervals and along the entire circumference, and at least along the arc-shaped cross section. It only needs to be buried side by side in the direction. The blocking member attached to cover the discharge port of the discharge channel formed in the connection connecting steel material does not necessarily need to be a vinyl tape wound around the outer peripheral surface of the connection connection steel material. For example, the discharge port is closed and fitted. Other various closing members such as a plug member to be attached may be used.

DESCRIPTION OF SYMBOLS 10 Pipe roof connection structure 11 Pipe roof material 12 Pipe roof 13 Connection connection steel material 13a Fluid supply path 13b Discharge flow path 13e Discharge port 13f Male thread protrusion 14 Pressure-resistant support ground body 15 Nut member 16 Fastening stand 17 Closure member (vinyl) tape)
20 Underground shaft 21 Rectangular propulsion pipe 22 Rectangular excavator 23 Steel lining body 23a Outer wall 26 Chemical solution injection pipe 27 Segment reinforcement support 30 Circumferential shield mine 31 Circumferential shield excavator 32 Curved section lining segment 33 Main jack 40 Saddle ground improvement body 41 Unit improvement body 43a Cylindrical lining wall 43b Saddle lining wall 46 Still water iron plate 47 Backfill filler 48 Sprayed concrete 49 Rock bolt 50 Widening tunnel 51 Main tunnel 52 Lamp tunnel

Claims (7)

In the ground of the outer peripheral part of the tunnel built in the ground, multiple pipe roof materials that extend in the tunnel extension direction and are arranged side by side in the direction along the arc-shaped cross section are connected to each other Then, it is used when providing a pipe roof connection structure that can support the load from the ground as a unit, and by compressing the ground at the space between each pair of adjacent pipe roof materials, a predetermined compression is achieved. A method of forming a pressure-resistant supporting ground body in a pipe roof that forms a pressure-resistant supporting ground body having strength,
The pipe roof connection structure includes a connection connecting steel material for fixing the ends of both sides to each pair of pipe roof materials adjacent to each other in the direction along the arc-shaped cross section and connecting the pipe roof materials to each other. A pressure-resistant supporting ground body provided to be interposed between the gap portions of each pair of adjacent pipe roof materials,
The connecting and connecting steel material includes a fluid supply path provided so as to penetrate in the axial direction, and a discharge flow path extending outward from the fluid supply path and having a discharge port opened on the outer peripheral surface in the axial direction. We prepare for plural places at intervals,
Covering each discharge port with a closing member attached to the connection connecting steel material with a joining strength that does not come off due to the water pressure of the drilling water supplied at the time of drilling but is released by the injection pressure when the ground improvement material is injected. In the attached state, the step of self-drilling the connection connecting steel material from one adjacent pipe roof material to the other pipe roof material, and then closing one end of the fluid supply path Then, by injecting the improved ground material from the other end portion, the blocking member is removed from the discharge port, and the ground improved material is spread over the ground of the interval portion of the adjacent pair of pipe roof materials, and improved. A method of forming a pressure-resistant supporting ground body in a pipe roof including a step of forming a ground.   The pipe roof according to claim 1, wherein the water pressure of the drilling water supplied at the time of drilling is 0.2 to 0.3 MPa, and the injection pressure when injecting the ground improvement agent is 0.5 to 3.0 MPa. A method for forming a pressure-resistant supporting ground body.   3. The method for forming a pressure-resistant supporting ground body in a pipe roof according to claim 1, wherein the blocking member is a vinyl tape that covers each of the discharge ports and is wound around an outer peripheral surface of the connection connecting steel material.   The connecting and connecting steel material is made of a steel rod having male threaded ridges formed at least at both ends, and the pipe ends are fastened to fastening bases provided inside the pipe roof material. The formation method of the pressure | voltage resistant support ground body in the pipe roof of any one of Claims 1-3 fixed to a roof material.   The said pipe roof material has a circular hollow cross-sectional shape, The formation method of the pressure | voltage resistant support ground body in a pipe roof of any one of Claims 1-4.   The plurality of pipe roof materials are embedded in a ground at an upper part of at least an upper portion of a tunnel built in the ground, arranged side by side in a direction along the arc-shaped cross section. A method for forming a pressure-resistant supporting ground body in the pipe roof according to the item.   The plurality of pipe roof members are embedded in the ground at the outer peripheral portion of the tunnel constructed in the ground, arranged in a circumferential direction along the circular cross section including the arc-shaped cross section at intervals. The formation method of the pressure | voltage resistant support ground body in the pipe roof of Claim 6 currently performed.