JP2007002603A - Construction method of underground structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method of an underground structure for easily integrating tunnels, while securing yield strength (resistance force) to earth pressure, in the underground structure constructed by using a plurality of juxtaposed tunnels. <P>SOLUTION: This construction method of the underground structure forms an inner peripheral part 3 along the inner periphery of an outer peripheral part 2 by forming the outer peripheral part 2 by leaving a lining 11 facing the peripheral ground G of these tunnels 1, 1 and 1 by juxtaposing the tunnels 1 in a plurality of rows and a plurality of stages. A removal section and a timbering section are alternately set in the tunnel axis direction, and the lining 11 becoming a hindrance when constructing the inner peripheral part 3 in the removal section is removed while using at least a part of the lining 11 except for the lining 11 being the outer peripheral part 2 in the timbering section as timbering, and after closing the inner peripheral part 3 in the removal section, the inner peripheral part 3 is closed in the timbering section after removing the lining 11 used as the timbering in the timbering section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for constructing an underground structure.

  Patent Document 1 discloses an underground structure built using a plurality of tunnels arranged side by side. This underground structure is constructed by arranging multiple tunnels vertically and horizontally so as to substantially encompass all of the cross section, and then removing unnecessary lining of each tunnel to form a large space Built. The plurality of tunnels are constructed sequentially with a time difference, and the succeeding tunnel is constructed next to the preceding tunnel. Each tunnel is constructed by a propulsion method or a shield method.

  Here, the propulsion method is a method of constructing a tunnel by sequentially injecting a cylindrical box as a tunnel lining from the wellhead into the ground. In addition, a blade edge, an excavation machine, etc. are attached to the front-end | tip of a box. The propulsion method excavating machine excavates by the thrust of the main jack transmitted through the box. On the other hand, the shield method is a method of excavating a natural ground with an excavator installed at a tunnel face and assembling a segment to be a tunnel lining inside the excavator to construct a tunnel. In addition, a shield machine makes itself a reaction force against the segment assembled inside.

  By the way, in the structure described in Patent Document 1, since the remaining lining of each tunnel is directly used as the bottom plate and the side wall of the underground structure, the lining of each tunnel is previously made heavy. There is a need. In other words, when the remaining lining of each tunnel is used as a main structure as it is, the thickness and strength of the lining of each tunnel is the same as the thickness and strength required for use in a closed-section tunnel ( That is, it is necessary to make it larger than the thickness and strength required at the time of construction.

JP 2001-214699 A (paragraph 0022, FIG. 1)

  However, if the lining of each tunnel is made so heavy that it can be used as it is as a main structure, the weight of the box and segments that make up the lining increases, so it is difficult to carry in and assemble it. There is a risk of hindrance.

  For this reason, a box structure or a segment of each tunnel is used as a primary lining, and after removing unnecessary portions inside, a concrete structure may be constructed by placing concrete as a secondary lining. However, in order to carry out such construction, it is necessary to replace the earth pressure with other structures once because the tunnel box and segment of each tunnel are dismantled under earth pressure. There was a problem that work was troublesome.

  From such a point of view, the present invention is a method for constructing an underground structure that is constructed by using a plurality of tunnels arranged side by side, and it is possible to integrate the tunnel while ensuring a resistance to earth pressure (resistance). It is an object to provide a construction method for an underground structure that can be simplified.

  The construction method of the underground structure according to the present invention, which was created to solve such a problem, includes a plurality of rows of tunnels arranged side by side, and a lining facing the surrounding ground of each tunnel is left behind. Forming an inner peripheral portion along an inner periphery of the outer peripheral portion, and a method for constructing an underground structure, wherein the plurality of multi-stage tunnels arranged side by side are removed in the tunnel axial direction. And the support section are alternately set, and at least a part of the lining other than the lining that becomes the outer periphery in the support section is used as a support, and it is an obstacle to construct the inner periphery in the removal section After removing the lining and closing the inner periphery in the removal section, after removing the lining used as support in the support section, closing the inner periphery in the support section It is a feature.

  This construction method of the underground structure secures the resistance (resistance) against external force such as earth pressure in the support section including the front and rear removal sections. Even if the lining other than the lining facing the ground is removed, the construction can be performed in a stable state. In addition, it is excellent in workability and economically because it is not necessary to replace the external force such as earth pressure by arranging new members or making the tunnel lining heavy beforehand. Moreover, since the construction of the inner periphery in the support section is performed according to the progress of the construction of the inner periphery in the front and rear removal sections, safety is ensured.

  In the invention according to claim 2, the tunnels are arranged in a plurality of stages in a plurality of rows, an outer peripheral portion is formed by leaving a lining facing the surrounding ground of each tunnel, and along the inner periphery of the outer peripheral portion. Forming an inner peripheral part, wherein the plurality of multi-stage tunnels arranged side by side alternately set removal sections and support sections in the tunnel axis direction, and the support sections Removing the lining that obstructs the construction of the inner peripheral portion in the removal section while using at least a part of the lining other than the lining serving as the outer peripheral portion in the removal section And the step of constructing the bottom plate of the inner peripheral portion in the removal section, and the covering that obstructs the construction of the side wall of the inner peripheral portion of the lining used as a lateral support in the support section. The process of removing the work and the removal zone And a step of constructing a side wall of an inner peripheral portion in the support section, a step of constructing a top plate of the inner peripheral portion in the removal section, and closing the inner peripheral portion, and as a vertical support in the support section The method includes a step of removing the used lining and a step of closing an inner periphery in the support section.

  The construction method of the underground structure is to construct the removal section in a state where the proof strength (resistance) is secured by the support section, and as the construction of the inner periphery in the removal section progresses, unnecessary lining of the support section is performed. In order to perform removal and construction of the inner periphery, it is preferable to appropriately replace earth pressure.

  This underground structure is a two-layer structure consisting of an outer periphery formed using the lining of each tunnel and facing the surrounding ground, and an inner periphery formed along the inner periphery. Therefore, by appropriately adjusting the thickness and strength of the inner peripheral portion, the load that the outer peripheral portion should bear after completion can be reduced. In other words, each tunnel only needs to have the thickness of the lining required at the time of construction (that is, the thickness required for a tunnel having a closed section), and therefore the lining of each tunnel is more than necessary. It will not be profound.

  Moreover, in the construction method of the underground structure according to the present invention, the linings adjacent in the tunnel axis direction may be connected to each other. In this way, since the adjacent linings are integrated between the support section and the removal section, external forces applied to the support section and the removal section can be appropriately exchanged with each other. It is possible to perform construction safely. Moreover, since adjacent linings will be integrated, the rigidity of an outer peripheral part can be improved. Adjacent linings may be connected to each other through, for example, a joint made of bolts and nuts or a joint using a wedge, or may be connected by welding.

  In addition, if the inner peripheral portion is configured to include concrete that is placed so as to straddle the boundary portion between the linings adjacent to each other in the tunnel crossing direction, when the plurality of tunnels are juxtaposed, the boundary A gap (seam) between the linings generated in the portion is blocked with concrete, and intrusion of groundwater or the like from this gap can be prevented. In addition, when placing concrete, the workability is good because the outer peripheral portion is directly used as a formwork on the peripheral ground side.

  Furthermore, you may embed the reinforcing bar arrange | positioned so that the said boundary part may be straddled in the said concrete. In this way, the rigidity of the inner peripheral portion is improved by the reinforcing effect of the reinforcing bars, and further, the remaining lining of each tunnel is connected to each other via the reinforcing bars, so the rigidity of the outer peripheral portion is also improved. Will be improved. In addition, when the lining of each tunnel is made of a steel member, a so-called open sandwich structure is formed together with the concrete, so that the concrete thickness of the inner periphery can be reduced, and The amount of reinforcing bars can be reduced compared to a simple reinforced concrete structure without an outer periphery.

  According to the construction method of an underground structure according to the present invention, each lining of a plurality of tunnels arranged side by side does not become unnecessarily heavy, and the tunnel is secured with resistance to earth pressure (resistance). Can be easily and quickly integrated.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings. Here, FIG. 1 is a cross-sectional view showing the underground structure according to the present embodiment. FIG. 2 is a perspective view showing the entire underground structure of the present embodiment. Moreover, FIG. 3 is a top view which shows the support area and removal section which concern on the construction method of the underground structure of this embodiment. Furthermore, FIG. 4 (a)-(f), FIG. 5 (a)-(f), FIG. 6 (a)-(c) shows each construction step which concerns on the construction method of the underground structure of this embodiment. FIG. 7 is a cross-sectional view, and FIG. 7 is a plan view showing the unboxing situation.

  As shown in FIG. 1, the construction method of the underground structure according to the present embodiment includes a plurality of tunnels 1 arranged in a plurality of rows (in this embodiment, two rows and three rows), and around each tunnel 1, 1,. A large-section tunnel (underground structure) T is constructed by leaving the lining facing the ground G, forming the outer peripheral portion 2, and forming the inner peripheral portion 3 along the inner periphery of the outer peripheral portion 2. It is. In this case, as shown in FIG. 3, the removal sections A and the support sections B are alternately set for each box 10 in the tunnel axis direction in the tunnels 1, 1,. In the support section B, the cover 11 that becomes an obstacle when the inner periphery 3 is constructed in the removal section A is removed while using at least a part of the cover 11 other than the cover 11 serving as the outer periphery 2 in the support section B. After the inner periphery 3 is closed in the removal section A, the lining 11 used as the support in the support section B is removed, and then the inner periphery 3 is closed in the support section B.

  As shown in FIG. 1, the large-section tunnel T according to this embodiment includes a plurality of (six in this embodiment) tunnels 1, 1,. The outer peripheral portion 2 that is constructed by using the outer peripheral portion 2 facing the surrounding ground G and the inner peripheral portion 3 formed along the inner periphery of the outer peripheral portion 2 is provided.

  In the present embodiment, as shown in FIG. 2, when a ramp portion is newly installed on the existing road R formed on the embankment E, it passes under the existing road R as an attachment road Ra to the existing road R. A large section tunnel (underground structure) T having a curved line shape is constructed.

  Here, as shown in FIG. 1, the cross section of the large-section tunnel T has a rectangular shape, and the cross section of each tunnel 1 has a substantially square shape. The plurality of tunnels 1, 1,... Have the same cross-sectional shape, and the total cross-sectional area of the plurality of tunnels 1, 1,. Are roughly equal. In the present embodiment, the cross section of each tunnel 1 is formed in a substantially square shape, but it goes without saying that the cross section of each tunnel 1 is not limited. The tunnels are joined together through joint means J provided to each other.

  Next, the lining 11 (lining structure) at the time of construction of each tunnel 1 will be described in detail. Here, each tunnel 1 can be constructed by a propulsion method or a shield method, but in this embodiment, a case of constructing by a propulsion method is illustrated. In addition, the lining 11 at the time of construction of the tunnel T faces the surrounding ground G and is left behind after completion of the large section tunnel T, and on the inner side of the inner peripheral portion 3. There is a lining 11b that is exposed and removed before completion. In the following description, the remaining lining 11a may be referred to as “remaining lining 11a”, and the removed lining 11b may be referred to as “removed lining 11b”.

  The box 10 (the lining 11) is adjacent to a skin plate (not shown) formed in a rectangular tube shape, a plurality of frame-shaped main girders (not shown) arranged at intervals in the tunnel axis direction. It includes a plurality of vertical ribs (not shown) arranged along the tunnel axis direction between the matching main girders.

  In the present embodiment, the box 10 is made of a steel member, but may be made of a spheroidal graphite cast iron member, or may be made of a reinforced concrete member. . Moreover, although illustration is abbreviate | omitted, you may comprise the box 10 combining several segments. In this case, if the joint (joint) of the segment is positioned at the boundary portion between the remaining lining 11a and the removal lining 11b, the removal lining 11b can be easily and quickly removed.

  Next, with reference to FIG. 1, the outer peripheral part 2 and the inner peripheral part 3 which comprise the large cross-sectional tunnel T are demonstrated in detail. In the following description, the tunnel crossing direction means the horizontal direction or the vertical direction in FIG.

  The outer peripheral part 2 is configured to include a plurality of remaining linings 11a, 11a,... Arranged so as to form a rectangular tube-shaped outer shell, and forms a permanent structure together with the inner peripheral part 3. Yes. That is, the outer periphery which functions as a part of this installation structure by the residual covering 11a of the cross-sectional substantially L shape facing the surrounding ground G among the coverings 11 of the cross-sectional rectangular frame shape of each tunnel 1 or a substantially single character cross-section. Part 2 is configured. The remaining linings 11a, 11a adjacent to each other in the tunnel crossing direction are connected to each other through joint means J. If it does in this way, since the remaining linings 11a and 11a adjacent in the tunnel crossing direction will be firmly integrated, the rigidity of the outer peripheral part 2 can be improved. In the present embodiment, as the joint means J, one in which the ridge formed on the other lining 11 is inserted into the groove portion formed on the one lining 11 is adopted, but the configuration of the joint means J is limited. However, it may be selected from known means as appropriate.

  The inner peripheral portion 3 is placed along the inner periphery of the outer peripheral portion 1 with a plurality of reinforcing bars (not shown) arranged at intervals in the tunnel axis direction (perpendicular to the paper surface in FIG. 1) as necessary. In this embodiment, a top plate TA, a bottom plate TB, and a side wall TC are provided.

Hereinafter, the construction method of the large-section tunnel T according to the present embodiment will be described in detail.
As shown in FIG. 1, the large-section tunnel T is constructed by arranging a plurality of tunnels 1, 1,... In parallel so as to substantially include all the cross-sections of the large-section tunnel T. The inner peripheral part 3 is constructed along the lining (outer peripheral part 2) facing the peripheral ground G.

  More specifically, the construction method of the large-section tunnel 1 is performed by a tunnel construction process and an inner circumference construction process described below.

  As shown in FIG. 1, the tunnel construction step is a step of arranging a plurality of tunnels 1, 1,... In parallel so as to substantially include all of the transverse cross section of the large-section tunnel T to be constructed. That is, the tunnel construction process is a process of constructing the tunnel 1 in each of a plurality of small areas obtained by equally dividing the area where the large-section tunnel T is constructed, and when the construction of all the tunnels 1 is completed. Thus, excavation and support of the area where the large section tunnel T is constructed is completed.

  The tunnel construction process will be described more specifically by referring to the plurality of tunnels 1, 1,. First, as shown in FIG. 1, a first tunnel 1a serving as a reference is constructed in a small area outside the lower portion of the large-section tunnel T to be built, and then a small area adjacent to the first tunnel 1a is constructed. The second tunnel 1b and the third tunnel 1c are constructed using the first tunnel 1a as a guide. Subsequently, a fourth tunnel 1d is constructed by using this as a guide in a small area adjacent to the first tunnel 1a (upper), and further, this is used as a guide in small areas adjacent to the tunnel 1d and the tunnel 1b. A fifth tunnel 1e is constructed, and a sixth tunnel 1f is constructed using these as a guide in a small area adjacent to the tunnel 1c and the tunnel 1e. The construction order of the tunnels 1a to 1f is not limited to the above, and may be changed as appropriate.

  Each tunnel 1 is constructed by sequentially pushing out (pushing) a plurality of boxes 10, 10,... During construction of the tunnel 1, a lubricant is poured and filled around the box 10 and replaced with a curable backing material after the construction of the tunnel 1 is completed. Although not shown in the drawings, the boxes 10 and 10 adjacent to each other in the tunnel axis direction in each tunnel 1 may be connected to each other using bolts, nuts, or the like (not shown). Here, in the present embodiment, the lubricant is injected and filled when the box 10 is arranged, and replaced with the backing material when the construction of the tunnel 1 is completed. However, any material that combines the lubricant and the backing material may be used. Needless to say, there is no need to replace it.

  The excavator used for the construction of the tunnel 1 may be one that excavates itself by taking a reaction force on the box 10 behind it (that is, one that is equipped with a propulsion jack). It may dig up by the thrust of the main push jack transmitted through it.

  The inner periphery construction process faces the surrounding ground G of each tunnel 1 and constructs the inner periphery 3 (the top plate TA, the bottom plate TB, and the side wall TC) along the outer periphery 2 that is the remaining lining. And is performed by the following first to seventh steps.

  As shown in FIG. 3, the construction of the underground structure is as follows: (1) Supporting a set of tunnels 1, 1,... In which removal sections A and support sections B are alternately set in the tunnel axis direction. While using the lining 11 of each tunnel 1, 1,... In the section B as the vertical struts 12 and the horizontal struts 13 (supports), the lining 11b other than the lining 11 left as the outer peripheral portion 2 in the removal section A A first step of removing (see FIGS. 4 (a) and 4 (b)), (2) a second step of constructing the bottom slab TB of the inner periphery 3 in the removed section A (FIG. 4 (c)) (3) A third step of removing the lining 11b at a portion corresponding to the side wall TC of the inner peripheral portion 3 in the support section B (see FIG. 4 (f)), (4) the removal section A and A fourth step of constructing the side wall TC of the inner periphery 3 in the support section B (see FIG. 5A And (b)), (5) the top plate TA of the inner peripheral portion 3 is constructed in the removal section A, and the inner peripheral portion 3 is closed (see FIG. 5C), (6) ) A sixth step of removing the lining 11b used as the vertical strut 12 in the support section B (see FIG. 5 (f)), and (7) a seventh process of closing the inner periphery 3 in the support section B ( (See FIG. 6B).

(1) First Step In the first step, as shown in FIG. 4B, in the support section B, the lining of each tunnel 1 is left as the vertical struts 12 and the horizontal struts 13 and includes the removal section A. Thus, the proof stress (resistance force) against the external force (earth pressure, etc.) P acting on the large-section tunnel T (tunnel aggregate) is held. At this time, since the linings adjacent to each other in the tunnel axis direction of each tunnel 1 are connected to each other, the outer peripheral portion 2 of the removal section A and the support section B is integrally configured to receive external force. On the other hand, in the removal section A, as shown in FIG. 4 (a), the linings 11 (other than the lining (remaining lining 11a) corresponding to the outer peripheral portion 2 are provided so that the inner peripheral portion 3 can be constructed. The removal lining 11b) is removed. In the present embodiment, all the removal lining 11b finally removed in the removal section A is removed in the first step, but the removal timing of the removal lining 11b is limited to this. Instead, for example, in the first step, only the removal lining 11b that gets in the way when the inner periphery 3 is constructed may be removed.

(2) Second Step In the second step, the bottom plate TB of the inner peripheral portion 3 is constructed in the removal section A as shown in FIG. Further, in the support section B, as shown in FIG. 4 (d), in the tunnels 1 and 1 at the lower right and the lower left, a bottom plate (hereinafter simply referred to as a base plate) corresponding to the leg portion of the side wall TC of the inner peripheral portion 3 is used. TB) (sometimes called “legs”). At this time, the external force P applied to the outer peripheral portion 2 is received by the vertical struts 12 and the horizontal struts 13 in the support section B.

In addition, the concrete is placed so as to straddle the boundary portion between the linings (the boundary portion between the removal section A and the support section B), and the bottom plate TB of the removal section A and the leg portion TB ′ of the support section B are continuous. It is desirable to build it as one. Further, the bottom plate TB of the removal section A and the leg portion TB ′ of the support section B are constructed with a predetermined distance from the vertical struts 12 of the support section B. As shown in FIG. It is constructed in a state where the box 3a is formed on the bottom plate TB of the part 3. That is, the bottom slab TB of the removal section A is formed to be narrower by an interval formed between the support strut B and the vertical struts 12 in the support section B.
Here, when constructing the bottom slab TB and the leg portion TB ′, reinforcing bars are arranged as necessary, and the reinforcing bars are also arranged at the boundary between the linings (the boundary between the removal section A and the supporting section B). It is assumed that the bars are arranged so as to straddle the part. Further, the bottom plate TB and the leg portion TB ′ are constructed in a state where a reinforcing bar (not shown) protrudes a predetermined length in advance at a joint portion with a side wall TC described later.

(3) Third Step In the third step, as shown in FIG. 4 (f), in the support section B, a removal lining 11b (in this embodiment) that becomes an obstacle when the side wall TC of the inner peripheral portion 3 is constructed. The lining 11b at the boundary between the upper right tunnel 1 and the lower right tunnel 1 and the lining 11b) at the boundary between the upper left tunnel 1 and the lower left tunnel 1 are removed. That is, as shown in FIG. 4 (e), the construction of the bottom plate TB in the removal section A is completed, and it is possible to handle the side pressure Pb by the bottom plate TB in the removal section A among the external force P applied to the outer peripheral portion 2. At this stage, as shown in FIG. 4 (f), the lateral pressure 13 in the support section B is cut to transfer the lateral pressure Pb from the lateral support 13 to the bottom plate TB in the removal section A. Therefore, as shown in FIGS. 4 (e) and 4 (f), the external force P applied to the large section tunnel T is the vertical strut 12 in the support section B for the vertical force Pa, and the removal section A for the horizontal force Pb. Take charge of the bottom plate TA.

(4) Fourth Step In the fourth step, the side wall TC of the inner peripheral portion 3 is constructed in the removal section A and the support section B as shown in FIGS. At this time, it is desirable that the side wall TC is constructed by continuously placing concrete so as to straddle the boundary portion between the linings (the boundary portion between the removal section A and the support section B). Further, reinforcing bars are arranged on the side wall TC as necessary, and the reinforcing bars are arranged so as to straddle the boundary portion between the linings. Further, the side wall TC is constructed in a state where a reinforcing bar (not shown) protrudes a predetermined length from a joint portion (upper end portion) with the top plate TA described later.

(5) Fifth Step In the fifth step, as shown in FIG. 5 (c), in the removal section A, the top plate TA of the inner peripheral portion 3 is applied and the inner peripheral portion 3 is closed. On the other hand, in the support section B, as shown in FIG. 5 (d), in the upper right tunnel 1 and the upper left tunnel 1, the top plate of the portion corresponding to the upper end portion of the side wall TC of the inner peripheral portion 3 (hereinafter simply referred to as “top plate”). TA ') (sometimes called "upper end"). At this time, as shown in FIGS. 5C and 5D, the external force P applied to the outer peripheral portion 2 is vertical force Pa is the vertical column 12 of the support section B, and horizontal force Pb is the bottom plate TB of the removal section A. I am in charge. Further, the top plate TA of the removal section A and the upper end portion TA ′ of the support section B are constructed with a predetermined distance from the vertical struts 12 of the support section B. As shown in FIG. It is constructed in a state where the box opening 3a is formed on the top plate TA of the peripheral portion 3. That is, the top plate TA of the removal section A is formed to be thin at the portion corresponding to the vertical support 12 of the support section B by the interval formed between the support section B and the vertical support 12.

(6) Sixth Step In the sixth step, the support section B is used as the vertical support 12 as shown in FIG. 5 (f) when the inner peripheral portion 3 of the removal section A reaches a predetermined strength. The lining 11 (removal lining 11b) is removed. That is, as shown in FIG.5 (e), since the inner peripheral part 3 of the removal area A is closed by completing construction of the top plate TA of the removal area A, the external force P adopted for the outer peripheral part 2 is applied. It becomes possible to take charge by the removal section A. Therefore, by removing the vertical struts 12 in the support section B, the vertical force Pa is transferred from the vertical struts 12 in the support section B to the removal section A.

(7) Seventh Step In the seventh step, as shown in FIG. 6 (b), the box opening 3a (formed on the bottom plate TB and the top plate TA of the inner peripheral portion 3 due to the presence of the vertical struts 12 in the support section B ( As for FIG. 7, the concrete is placed and the inner peripheral portion 3 of the support section B is closed. As a result, as shown in FIGS. 6A and 6B, the inner peripheral portion 3 is closed in the removal section A and the support section B, and the outer shell of the large-section tunnel T is completed.

  When the construction of the inner peripheral portion 3 of the large section tunnel T is completed by the seventh step, various structures 4 inside the large section tunnel T are constructed as shown in FIG. Finalize.

  As described above, the large-section tunnel T has a two-layer structure of the outer peripheral portion 2 formed using the lining 11 of each tunnel 1 and the inner peripheral portion 3 formed along the inner periphery. Therefore, the load which the outer peripheral part 2 should bear after completion can be made small by adjusting the thickness and intensity | strength of the inner peripheral part 3 suitably. That is, each tunnel 1 only needs to have a proof strength (resistance force) corresponding to the external force P as the thickness of the lining 11 required at the time of construction or the vertical support 12 and the horizontal support 13. The T lining 11 does not become thicker than necessary.

Further, when the large-section tunnel T is constructed by the construction procedure as described above, the lining 11 of each tunnel 1 is necessary in order to appropriately transfer the external force P applied to the outer peripheral portion 2 to the remaining lining 11a or the inner peripheral portion 3. It is not necessary to make it heavy.
Moreover, since the construction of the inner peripheral portion 3 is performed after the lining 11 corresponding to the inner peripheral portion 3 is removed, the construction is not hindered, and the inner peripheral portion 3 is removed after completion. Compared with, removal work is easy.

  According to the construction method of the underground structure of the present embodiment, it is possible to easily integrate a plurality of tunnels arranged side by side while ensuring the proof stress (resistance force) against earth pressure. .

As mentioned above, although preferred embodiment was described about this invention, this invention is not limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the case where the cross section of the large-section tunnel is rectangular is illustrated (see FIG. 1), but the present invention is not limited to this. For example, an L-shape, a T-shape, a U-shape It may be a shape, a concave shape, or the like. Also, the cross section of each tunnel is not limited to a rectangle, and for example, it may have a rounded quadrangular shape or an oval shape.

  In the above embodiment, the tunnel having the same size and shape is constructed in each of a plurality of small regions obtained by equally dividing the region in which the large-section tunnel is constructed (see FIG. 1). There is no need to split. That is, as long as the sum of the cross-sectional areas of a plurality of tunnels is approximately equal to the cross-sectional area of the large cross-section tunnel, the cross-sectional dimensions and shapes of each tunnel may be two or more types. .

  In the embodiment described above, the case where the region where the large-section tunnel is constructed is divided into two rows and three rows is exemplified. However, it goes without saying that the region dividing method is not limited to this.

Moreover, in the said embodiment, although the construction method of the underground structure of this invention shall be employ | adopted about the attachment road of a ramp part constructed | assembled by traversing the downward direction of the existing road, The application location of the construction method is not limited.
Similarly, in the above-described embodiment, a large-section tunnel having a curved line shape has been described, but it goes without saying that the present invention can also be applied to a case of a linear line shape.

It is sectional drawing which shows the underground structure concerning this embodiment. It is a perspective view which shows the whole underground structure of this embodiment. It is a top view which shows the support area and removal section which concern on the construction method of the underground structure of this embodiment. (A)-(f) is sectional drawing which shows each construction step which concerns on the construction method of the underground structure of this embodiment. (A)-(f) is sectional drawing which shows each construction step which concerns on the construction method of the underground structure of this embodiment. (A)-(c) is sectional drawing which shows each construction step which concerns on the construction method of the underground structure of this embodiment. It is a top view which shows the boxing situation of the large section tunnel which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tunnel 2 Outer peripheral part 3 Inner peripheral part 10 Box 11 Covering 11a Remnant covering 11b Removal covering 12 Vertical support 13 Horizontal support A Removal area B Supporting section T Large section tunnel (underground structure)

Claims (3)

An underground structure in which a plurality of rows of tunnels are arranged side by side, an outer peripheral portion is formed by leaving a lining facing the surrounding ground of each tunnel, and an inner peripheral portion is formed along the inner periphery of the outer peripheral portion. The construction method of
In the multiple-stage multiple-row tunnels arranged side by side, the removal section and the support section are alternately set in the tunnel axis direction,
Removing the lining that obstructs the construction of the inner periphery in the removal section while using at least a part of the lining other than the lining as the outer periphery in the support section,
After closing the inner periphery in the removal section, after removing the lining used as support in the support section, and closing the inner periphery in the support section, Construction method. An underground structure in which a plurality of rows of tunnels are arranged side by side, an outer peripheral portion is formed by leaving a lining facing the surrounding ground of each tunnel, and an inner peripheral portion is formed along the inner periphery of the outer peripheral portion. The construction method of
In the multiple-stage multiple-row tunnels arranged side by side, the removal section and the support section are alternately set in the tunnel axis direction,
Removal of the lining that obstructs the construction of the inner periphery in the removal section while using at least a part of the lining other than the lining as the outer periphery in the support section as a vertical support or a horizontal support. A process of performing
Constructing the bottom plate of the inner periphery in the removal section; and
Of the lining used as the horizontal strut in the support section, removing the lining that obstructs the construction of the side wall of the inner periphery, and
A step of constructing a side wall of the inner periphery in the removal section and the support section;
Constructing the top plate of the inner periphery in the removal section, and closing the inner periphery;
Removing the lining used as the vertical support in the support section;
Closing the inner periphery in the support section;
A method of constructing an underground structure, comprising:   The underground structure according to claim 1, wherein the linings adjacent to each other in the tunnel axis direction are connected to each other.

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