JP2012026242A - Construction method of underground structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of an underground structure capable of constructing a high-quality underground structure with excellent workability.SOLUTION: Steel pipes 13 are roughly straight in an axial direction and are installed in an arch shape so as to cross over the upper part of tunnels 5. On the outer part of the steel pipe 13, plate members 15 are provided. The plate members 15 are bonded to the steel pipe 13 beforehand by welding or the like, and are formed along the longitudinal direction of the steel pipe 13. Openings 17 are provided on a side face (the side facing to an adjacent steel pipe 13) of the steel pipe 13 from the inside of the steel pipe 13. The opening 17 is formed at a prescribed interval in the axial direction of the steel pipe 13. A dowel 24 is provided on a side face of the adjacent steel pipe 13 from the opening 17. Then, a mold 25 is installed so as to close the opening 17 inside the steel pipe 13, and mortar 27 is placed in an area below the plate members 15 between the steel pipes 13.

Description

  The present invention relates to a construction method for an underground structure such as a structure constructed between tunnels.

  Conventionally, as one of the construction methods of underground structures such as when constructing a structure between a pair of tunnels, a pipe roof was constructed above the structure construction position, and the pipe roof was excavated and excavated. There is a method of constructing a structure in space.

  As a method of constructing an underground structure using such a pipe roof, for example, a plurality of elementary pipes are arranged in a rectangular shape or the like according to the excavation shape, and the pipes are constructed by connecting the elementary pipes with joints. There is a method (Patent Document 1).

  Similarly, there is a pipe roof construction method in which an injection pipe is inserted into a joint between steel pipes and an injection material is injected into the joint (Patent Document 2).

JP-A-10-169361 Japanese Patent Laid-Open No. 10-37656

  However, in the pipe roof construction method described in either Patent Document 1 or Patent Document 2, since a joint is required, it is necessary to drive the steel pipe in a state where the joints are connected to each other, and ensuring the precision of the joint. In addition, there are problems such as securing the accuracy of placing the steel pipe and complication of the structure of the steel pipe.

  In particular, in the above-described pipe roof, unless the joints are securely connected to each other, the function of the pipe roof that prevents the collapse of the earth and sand from above cannot be exerted. For example, the pipe roof is installed while a temporary support is installed below the pipe roof. When excavating the lower part of the roof and excavating the part where the underground structure is planned to be installed, it is necessary to construct the underground structure with the receiving support installed, receiving the load from above by the receiving support. Work is complicated. In addition, since the receiving support work is buried in the underground structure, there is also a problem in the frame quality.

  This invention is made | formed in view of such a problem, and it aims at providing the construction method of an underground structure which is excellent in workability | operativity and can construct | assemble a high quality underground structure.

  In order to achieve the above-described object, the present invention is a method for constructing an underground structure, in which a plurality of steel pipes are placed above a planned construction portion of the underground structure, and a direction substantially perpendicular to the longitudinal direction of the steel pipe The step (a) of forming an arch-shaped pipe roof, the step (b) of forming an opening on the side of the adjacent steel pipe from the inside of the steel pipe, and the sand between the steel pipes from the opening Step (c) for removing, Step (d) for integrating the steel pipes by placing a compression force transmitting member between the steel pipes from the opening, and excavating the lower part of the pipe roof sequentially. And a step (e) of constructing an underground structure below the pipe roof, and a construction method for the underground structure.

  You may comprise the process (f) which provides a compressive force transmission member holding member in the side surface of the said adjacent steel pipe from the said opening part after the said process (c).

  The positions where the openings are formed may be staggered with respect to the longitudinal direction of adjacent steel pipes.

  You may further comprise the process (g) which improves the ground above the said pipe roof at least from the said pipe roof after the said process (b). In this case, the step (g) is a step of freezing and water-stopping the ground with a freezing pipe. In the step (d), a heat transmission member is installed on the inner surface of the frozen ground and a compressive force transmission member is placed. Good.

  Further, the step (g) is a step of freezing and water-stopping the ground with a freezing pipe, and a compressive force transmission member mixed with an anti-freezing material may be placed during the step (d).

  The steel pipe to be cast is joined with a sand removal part partition member extending in the direction of the adjacent steel pipe along the longitudinal direction of the steel pipe, and the step (c) includes a lower part of the soil removal part partition member. The earth and sand may be removed.

  The underground structure is a junction of tunnels, and the pipe roof is formed so as to straddle a pair of tunnels, and the step (e) constructs a tunnel junction by excavating between the pair of tunnels. It may be a process to do.

  According to the present invention, since the pipe roof is formed in an arch shape in a direction perpendicular to the longitudinal direction of the steel pipe, the pipe roof can efficiently receive a load from above by the arch effect. Further, since the steel pipes are integrated by a compressive force transmitting member that is driven between the steel pipes, a joint or the like is unnecessary. The compressive force transmitting member is a member capable of transmitting a compressive force acting between steel pipes by solidifying, such as mortar, concrete, fluidized soil, manmade rock, manmade soil, and the like.

  Moreover, since an opening part is formed from the inside of a steel pipe and the earth and sand between steel pipes are removed from an opening part, even if it is a long pipe roof, earth and sand can be removed reliably. Therefore, it is possible to integrate the pipe roof from the inside of the steel pipe.

  Moreover, a compressive force transmission member and a steel pipe can be integrated more reliably by providing a gibber on the side surface of the steel pipe adjacent from the opening before placing the compressive force transmission member. Moreover, since the compression transmission member holding member is provided after installing the steel pipe, the compression transmission member holding member does not get in the way when the steel pipe is installed. In addition, the compression transmission member holding member is a member such as a stud gibber, a plate diver, or a shape steel diver, and it is only necessary to prevent the displacement between the compression force transmission member and the steel pipe.

  Moreover, if an opening part is arrange | positioned in zigzag form with respect to the longitudinal direction of adjacent steel pipes, the installation pitch of an opening part can be enlarged and construction of an opening part will be easy. Moreover, when providing a dive, since a dive is arrange | positioned with respect to the longitudinal direction of a steel pipe, steel pipes can be integrated more reliably.

  In addition, when a freezing pipe is installed and the ground is frozen and stopped by the freezing pipe, if a heat insulating material is previously installed on the inner surface of the freezing ground, the compression force transmitting member to be placed will not freeze. Moreover, freezing of a compressive force transmission member can be similarly prevented by mixing an anti-freezing material with the compressive force transmission member.

  Moreover, if the earth and sand removal part division member is provided between steel pipes, the earth and sand between steel pipes can be easily excavated by the earth and sand removal part division member.

  Further, since the pipe roof is formed so as to straddle the tunnel, the force from the arched pipe roof can be received by the tunnel.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in workability | operativity and can provide the construction method of an underground structure which can construct | assemble a high quality underground structure.

(A) is a figure which shows underground structure 1, (b) is a figure which shows underground structure 1 '. It is a figure which shows the state which installed the steel pipe 13 in the arch shape, (a) is the figure seen from the tunnel axial direction, (b) is the sectional view on the AA line of (a). It is a figure which shows the state which freeze-stopped the ground above the pipe roof 7, (a) is an enlarged view in the B section of FIG. 2, (b) is a general view. It is a figure which shows the state which provided the opening part 17 in the steel pipe 13, (a) is an enlarged view in the B section of FIG. 2, (b) is a top view. The figure which shows the state which provided the jivel 24 between steel pipes. The figure which shows the state which nailed mortar 27 between the steel pipes 13. The figure which shows the state which excavated the underground structure installation range between the tunnels 5. FIG.

  Hereinafter, the construction method of the underground structure concerning embodiment of this invention, etc. are demonstrated. Fig.1 (a) is a figure which shows the underground structure 1 constructed | assembled by this invention. The underground structure 1 is composed of a pair of tunnels 5 provided below the ground 3 and a casing 9 that constitutes a joining portion and the like formed between the tunnels 5. In addition, if this invention is a structure constructed | assembled underground, it is not restricted to the example of Fig.1 (a).

  The housing 9 is constructed between the tunnels 5 and a pipe roof 7 is formed above. That is, the housing 9 is constructed in a space formed below the pipe roof 7. In addition, the support body etc. which supported the pipe roof 7 at the time of constructing the housing 9 are not embedded in the housing 9. The pipe roof 7 can be of any cross-sectional shape other than a circular cross-section steel pipe. For example, as shown in FIG. 1B, the pipe roof 7 'may be formed using a steel pipe having a rectangular cross section. In the following example, an example using a steel pipe having a circular cross section will be described.

  Next, the construction method of the underground structure 1 will be described. FIG. 2 is a view showing a state in which the pipe roof 7 is constructed above the tunnel 5, FIG. 2 (a) is a view as seen from the tunnel axial direction, and FIG. 2 (b) is an AA view of FIG. It is line sectional drawing. First, as shown in FIG. 2, the shaft 11 is constructed in the vicinity of the end of the underground structure construction part between the tunnels 5 constructed underground. Next, the pipe roof 7 is constructed by driving a plurality of steel pipes 13 from the shaft 11. In addition, you may perform construction of a pipe roof not only from a vertical shaft but from a slope or an existing frame.

  The steel pipe 13 has an inner diameter of about 1 m, for example, and an operator can enter the inside. Therefore, the following steps can be performed inside the steel pipe 13 by the operator entering the steel pipe 13 from the shaft side. The steel pipe 13 is substantially straight in the axial direction, and is installed in an arch shape so as to straddle the tunnel 5. That is, both end portions of the pipe roof 7 are positioned substantially at the top of the tunnel 5, the pipe roof 7 is located between the tunnels 5, and the plurality of steel pipes 13 are in a direction substantially perpendicular to the axial direction of the steel pipe 13. Arranged in an arch shape.

  Next, as shown in FIG. 3, the ground improvement above the pipe roof 7 is performed as necessary. 3A is an enlarged view of a portion corresponding to the portion B in FIG. 2, and FIG. 3B is an overall view. As shown in FIG. 3A, a freezing pipe 19 is installed above the inside of the steel pipe 13 (for example, a position of about 45 degrees on both sides from the center of the steel pipe 13). A refrigerant can be flowed into the freezing pipe 19 by a pump or the like (not shown). The arrangement and number of the freezing tubes 19 are not limited to the illustrated example. Moreover, although a freezing pipe may be provided in the steel pipe beforehand, you may install separately in an adjacent ground so that it may adjoin to a pipe roof.

  A plate member 15 that is a sediment removing part partition member is provided at a position substantially corresponding to the installation position of the freezing pipe 19 outside the steel pipe 13. The plate member 15 is joined to the steel pipe 13 in advance by welding or the like, and is formed along the longitudinal direction of the steel pipe 13. The plate member 15 is provided toward both sides of the steel pipe 13. When the steel pipe 13 is driven, as shown in FIG. 3A, the steel pipe 13 is driven at a predetermined interval so that the plate members 15 of the adjacent steel pipes 13 overlap each other. In addition, although the plate member 15 is a steel plate, for example, a plate shape and other forms may be sufficient if the range which removes the earth and sand between steel pipes can be divided.

  When a refrigerant is passed through the freezing pipe 19, the upper part of the steel pipe 13 (the upper part between the steel pipes 13) becomes the frozen soil 21, as shown in FIG. That is, the soil above the plate member 15 (in the vicinity of the plate member 15) is frozen. Therefore, the upper part between the steel pipes 13 is stopped. In addition, since the upper part of the plate member 15 between the steel plates 13 is frozen and stopped, the plate member 15 does not need to be strong enough to handle the earth and sand from above.

  By performing such ground improvement on the entire pipe roof 7, as shown in FIG. 3 (b), frozen soil 21 is formed on the entire upper portion of the pipe roof 7. Water can be done. The ground improvement is not limited to freezing. For example, instead of the freezing pipe, a pipe for injecting chemical liquid may be provided in the steel pipe 13, and the upper portion of the pipe roof 7 may be stopped by injecting chemical liquid.

  Next, the opening part 17 is provided in the side surface (adjacent steel pipe 13 side) of the steel pipe 13 from the inside of the steel pipe 13. FIG. 4 is a view showing a state in which the opening 17 is provided on the side of the steel pipe 13. As shown to Fig.4 (a), the opening part 17 is formed in the side of the steel pipe 13, and the earth and sand between the steel pipes 13 are excavated and removed. That is, the excavation part 23 is formed between the steel pipes 13. The excavation between the steel pipes 13 may be performed by excavating the earth and sand below the plate member 15. Although not shown, a similar plate member may be formed not only above the steel pipe 13 but also below, and the steel pipes 13 in a range surrounded by the upper and lower plate members may be excavated. .

  As shown in FIG. 4B, the openings 17 are formed at predetermined intervals in the axial direction of the steel pipe 13. The openings 17 are desirably arranged in a staggered manner with respect to the axial direction of the steel pipes 13 between the adjacent steel pipes 13. By carrying out like this, the installation pitch of the opening part 17 in the one side of the steel pipe 13 can be widened, and the strength reduction of the steel pipe 13 can also be suppressed. Moreover, the size of the opening part 17 should just excavate the earth and sand between the steel pipes 13, for example, is about 500 mm square.

  In addition, even when excavating between the steel pipes 13, the upper part of the pipe roof 7 (between the steel pipes 13) is stopped by the frozen soil 21, so that no water leaks from the upper part of the pipe roof 7. Sediment does not fall.

  Next, as shown in FIG. 5, a dowel 24 is provided on the side surface of the adjacent steel pipe 13 from the opening 17 of the steel pipe 13. That is, at a portion corresponding to the opening portion 17 in the axial direction of the steel pipe 13, a diver 24 is formed on the side surface of the adjacent steel pipe 13 facing the opening portion 17.

  Next, as shown in FIG. 6, inside the steel pipe 13, a mold 25 is installed so as to close the opening 17, and a compression force transmitting member is provided between the steel pipes 13 and below the plate member 15. A mortar 27 is placed. In addition, the mortar 27 may be driven at once over the entire length of the steel pipe 13 in a state in which all the openings 17 facing the excavation part 23 between the steel pipes 13 are closed, or in the longitudinal direction of the steel pipe 13. In some cases, a formwork may be provided so as to partition the excavation part 23 in the axial direction, and the excavation part 23 may be divided into a plurality of times. The mortar 27 may be placed from the shaft side or from the opening 17.

  Here, before the mortar 27 is placed, it is desirable that the heat insulating material 29 be installed on the inner surface of the plate member (the inner surface of the frozen soil 21) in advance. This is because the mortar 27 is cooled by the freezing pipe 19 (frozen soil 21) and is prevented from freezing. Moreover, freezing of the mortar 27 can be more reliably prevented by mixing an anti-freezing material in advance as the mortar 27.

  When the mortar 27 is consolidated, the steel pipes 13 are integrated. At this time, since the dowels 24 are provided at predetermined intervals on the side surface of the steel pipe 13, the mortar 27 and the steel pipe 13 are reliably integrated. The mold 25 may be removed after the mortar 27 is consolidated, or may be embedded as it is.

  When the steel pipes are integrated over the entire length by the above steps, the inside of each steel pipe 13 is also filled with mortar. Therefore, a high-strength pipe roof can be obtained. Next, a target part below the pipe roof 7 is excavated to construct a structure. FIG. 7 is a view showing a state where the lower part of the pipe roof 7 is excavated. As shown in FIG. 7, since the pipe roof 7 is completely integrated at the upper side, the pipe roof 7 can handle the upper earth pressure. For this reason, it is not necessary to install a support or the like at the lower part of the pipe roof 7, and the housing and the support work do not interfere when the housing is installed.

  Further, both ends of the pipe roof 7 are located in the upper part near the top of the tunnel 5. For this reason, the tunnel 5 can take charge of the force from the pipe roof 7 that receives the earth pressure above. In addition, in the vicinity of the gap (F portion in the figure) between the pipe roof 7 and the tunnel 5, the water is stopped in advance by chemical solution injection or the like.

  According to the construction method of the underground structure according to the present embodiment, the pipe roof 7 is preliminarily formed in the arch shape above the construction part of the frame, so that the pipe roof 7 can take over the earth pressure from above, There is no need to install a support work at the building construction site. For this reason, a support work and a frame do not interfere at the time of frame construction.

  Moreover, since the steel pipe 13 used for the pipe roof 7 does not require a joint or the like, the steel pipe 13 can be easily manufactured and installed. Further, by providing the plate member 15, there is no fall of earth and sand from above the pipe roof 7 during excavation, and since the excavation area is clear, there is no excessive dug above the pipe roof.

  Further, when the freezing pipe 19 is used for ground improvement, the mortar 27 is not frozen by providing the heat insulating material 29 on the inner surface of the plate member 15. In addition, freezing of the mortar 27 can be reliably prevented by mixing the mortar 27 with an anti-freezing material.

  Moreover, since the removal of the earth and sand between steel pipes is performed from the inside of the steel pipe 13, excavation work is easy. Further, by providing the dowel 24 on the side surface of the adjacent steel pipe 13 facing from the opening portion 17, it is not necessary to provide a gibber or the like when placing the steel pipe 13, and the placing of the steel pipe 13 is easy. Moreover, it is also possible to drive the mortar 27 from the opening 17, and the driving of the mortar 27 is easy.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, if a connecting member that connects both ends of the pipe roof 7 in the horizontal direction is provided after excavating the pipe roof 7 below, the arch shape below the pipe roof 7 spreads and the pipe roof 7 collapses more reliably. Can be prevented.

DESCRIPTION OF SYMBOLS 1 ......... Underground structure 3 ......... Ground 5 ......... Tunnel 7 ......... Pipe roof 9 ......... Housing 11 ......... Shaft 13 ......... Steel pipe 15 ......... Plate member 17 ......... Opening 19 ......... Freezing pipe 21 ......... Frozen soil 23 ......... Excavation section 24 ......... Givel 25 ......... Formwork 27 ......... Mortar 29 ......... Insulation

Claims (8)

A construction method for an underground structure,
A step (a) of placing a plurality of steel pipes above the planned construction portion of the underground structure, and forming an arched pipe roof in a direction substantially perpendicular to the longitudinal direction of the steel pipes;
From the inside of the steel pipe, a step (b) of forming an opening on the adjacent steel pipe side;
A step (c) of removing earth and sand between the steel pipes from the opening;
A step (d) of integrating the steel pipes by placing a compressive force transmitting member between the steel pipes from the opening;
A step (e) of sequentially excavating a lower portion of the pipe roof and constructing an underground structure at a lower portion of the pipe roof;
The construction method of an underground structure characterized by comprising.   The construction of an underground structure according to claim 1, further comprising a step (f) of providing a compressive force transmission member holding member on the side surface of the adjacent steel pipe from the opening after the step (c). Method.   The construction method for an underground structure according to claim 1 or 2, wherein the positions where the openings are formed are arranged in a staggered manner with respect to the longitudinal direction of adjacent steel pipes.   4. The method according to claim 1, further comprising a step (g) of improving the ground at least above the pipe roof from the pipe roof after the step (b). 5. Construction method for underground structures.   The step (g) is a step of freezing and water-stopping the ground with a freezing pipe, and in the step (d), a compressive force transmitting member is placed after installing a heat insulating material on the inner surface of the frozen ground. The construction method of the underground structure of Claim 4.   5. The step (g) is a step of freezing and water-stopping the ground with a freezing pipe, and a compressive force transmission member mixed with a defrosting material is placed during the step (d). Or the construction method of the underground structure of Claim 5. The steel pipe to be placed is joined along the longitudinal direction of the steel pipe with a sand and sand removal section partition member projecting in the direction of the adjacent steel pipe,
The said process (c) removes the earth and sand of the lower part of the said earth and sand removal part division member, The construction method of the underground structure in any one of Claims 1-6 characterized by the above-mentioned. The underground structure is a junction of tunnels, and the pipe roof is formed to straddle a pair of tunnels,
The construction method for an underground structure according to any one of claims 1 to 7, wherein the step (e) is a step of excavating the pair of tunnels to construct a tunnel junction.

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