JP6791586B2 - Structure of support work in tunnel and installation method of support work - Google Patents

Description

The present invention relates to a structure of a support in a tunnel and a method of installing the support, for example, a technique for connecting members having a vertical relationship in the tunnel.

In the excavation work of the tunnel, steel supports (support works) are installed at predetermined intervals along the longitudinal direction of the tunnel so that the tunnel does not collapse. In the installation work of each support, the lower half support is usually provided below the upper half support, but if the ground is weak, etc., the invert support is further placed on the bottom of the tunnel below the lower half support. I am trying to set up a work. Ordinary bolts and nuts are used for the connection between the upper half support and the lower half support and the connection between the lower half support and the invert support.

By the way, in the installation work of the support work, before installing the lower support work (lower half support work or invert support work), the inner surface of the upper support work (upper half support work or lower half support work) is concrete. However, if the connection part of the upper support is covered with concrete when installing the lower support, the upper and lower support cannot be connected to each other.

Therefore, usually, before the installation work of the lower support work, the part corresponding to the connection part with the lower support work is scraped off in the concrete covering the inner surface of the upper support work, or so-called scraping work is performed. Before covering the inner surface of the upper support with concrete, a box-shaped member is put on the inner surface of the upper support at the portion corresponding to the connection with the lower support, so-called box removal work or the like is performed.

The tunnel lining segment is described in Patent Document 1, for example, and discloses a structure in which a bag nut is embedded in a connecting portion of the segment.

Japanese Unexamined Patent Publication No. 8-13992

However, the above-mentioned chipping work and box removal work are troublesome work that requires time and labor, and there is a problem that the efficiency of the installation work of the support work is lowered. In recent years, the length of the tunnel has been increasing, and the longer the tunnel length, the more the number of support works installed. Therefore, how to improve the efficiency of the installation work of the support works has become an important issue.

The present invention has been made from the above-mentioned technical background, and an object of the present invention is to provide a technique capable of improving the efficiency of installation work of a support work in a tunnel.

In order to solve the above problems, the structure of the support work in the tunnel of the present invention according to claim 1 includes a first support work member extending from the ceiling to the middle of the side surface along the inner surface of the tunnel, and the first support member. A first connecting plate provided on the lower end surface of the supporting member so as to intersect the extending direction of the first supporting member, and a first connecting plate punched in the first connecting plate. The first support including the bolt hole, the first bag nut joined on the first connecting plate with the nut hole aligned with the first bolt hole, and the first bag nut. first and concrete which is sprayed so as to cover the upper portion of the inner surface lower end of Engineering member, a second shoring member extending downward than the lower end surface of the first shoring members, the second A second connecting plate provided on the upper end surface of the supporting member of No. 1 in a state of intersecting the extending direction of the second supporting member and in contact with the first connecting plate, and the second connecting plate. Through the second bolt hole drilled at a position facing the first bolt hole, the first bolt hole, and the second bolt hole in the connection plate, the first connection plate and the second bolt hole Including the first bolt which is screwed into the first bag nut via the connecting plate and connects the first support member and the second support member, and the first bolt. It is characterized by including a second concrete sprayed so as to cover an inner surface above the lower end of the second support member.

Further, according to the second aspect of the present invention, in the structure of the support work in the tunnel according to the first aspect, the second support member extends on the lower end surface of the second support member. A third connecting plate provided so as to intersect with respect to a direction, a third bolt hole drilled in the third connecting plate, and the third bolt hole on the third connecting plate. The second bag nut joined with the nut holes aligned and the second bag nut sprayed so as to cover the inner surface above the lower end of the second support member including the second bag nut. A third support member provided in a state of bridging the concrete and the legs of the second support member on both side surfaces in the width direction of the tunnel, and an upper end surface of the third support member. In addition, a fourth connecting plate that intersects the extending direction of the third support member and is provided in contact with the third connecting plate, and the third connecting plate in the fourth connecting plate. Through the fourth bolt hole drilled at a position corresponding to the bolt hole, the third bolt hole and the fourth bolt hole, and through the third connection plate and the fourth connection plate. A second bolt that is screwed into the second bag nut and connects the second support member and the third support member, and the third support member including the second bolt. It is characterized by further comprising a third concrete sprayed so as to cover the inner surface of the.

Further, the method of installing the support work in the tunnel of the present invention according to claim 3 is (a) excavating the ground to form an upper tunnel, extending from the ceiling along the inner surface of the tunnel, and the tunnel. The step of installing the first support member terminating at the bottom surface of the first support member, and (b) the step of spraying the first concrete on the inner surface of the tunnel including the inner surface of the first support member above the lower end. c) After the step (b), the step of excavating the ground below the leg of the first support member to form a lower excavation area, and (d) the lower side of the leg of the first support member. A step of installing a second support member extending from the lower end surface of the first support member and ending at the bottom surface of the lower excavation region on the side surface of the lower excavation region, and (e). After the step of connecting the first support member and the second support member and (f) the step (e), the lower side including the inner surface above the lower end of the second support member. It has a step of spraying a second concrete on the inner surface of the excavation area, and the lower end surface of the first support member intersects the extending direction of the first support member. The first plug nut is joined on the first connecting plate in a state where the nut hole is aligned with the first bolt hole drilled in the first connecting plate. in which, the upper end surface of the second shoring members, the which second connection plate is provided which intersects the extending direction of the second shoring members, in the second connection plate A second bolt hole is drilled at a position facing the first bolt hole, and in the step (d), the first connection plate of the first connection plate of the first support member is formed. The second bolt hole of the second connecting plate of the second support member is aligned with the bolt hole, and the second connecting plate is brought into contact with the first connecting plate. In the step (e), the first cap nut is provided from the lower surface side of the second connecting plate through the second bolt hole and the first bolt hole. It is characterized by having a step of connecting the first support member and the second support member by screwing the first bolt into the.

Further, according to the fourth aspect of the present invention, in the method of installing the support work in the tunnel according to the third aspect, (g) after the step (f), the lower side of the leg of the second support member. A step of excavating the ground to form an invert excavation area, and (h) a step of installing a third support member in the invert excavation area below the leg of the second support member. (I) A step of connecting the second support member and the third support member, and (j) a third on the inner surface of the invert excavation region including the inner surface of the third support member. It has a step of spraying concrete, and a third connecting plate that intersects the extending direction of the second supporting member is provided on the lower end surface of the second supporting member. On the third connecting plate, a second bag nut is joined in a state where the nut hole is aligned with the third bolt hole drilled in the third connecting plate, and the third support is provided. A fourth connection plate that intersects the extending direction of the third support member is provided on the upper end surface of the work member, and the fourth connection plate faces the third bolt hole. A fourth bolt hole is drilled at the position to be formed, and in the step (h), the fourth connection is made to the third bolt hole of the third connection plate of the second support member. The step (i) includes a step of aligning the fourth bolt holes of the plates and installing the third support member in a state where the fourth connecting plate is in contact with the third connecting plate. In, the second support is provided by screwing a second bolt into the second cap nut from the lower surface side of the fourth connection plate through the fourth bolt hole and the third bolt hole. It is characterized by having a step of connecting the work member and the third support work member.

According to the present invention, in the installation work of the support work, it is possible to eliminate the chipping work and the box removal work, so that the efficiency of the installation work of the support work can be improved.

(A) is a cross-sectional view of a main part intersecting in the longitudinal direction of the tunnel during the support installation process according to the embodiment of the present invention, and (b) is an enlarged cross section of the region A1 surrounded by the broken line in FIG. 1 (a). It is a figure. (A) is a cross-sectional view of a main part of a tunnel during a support installation process following FIG. 1, and (b) is an enlarged cross-sectional view of a region A1 surrounded by a broken line in FIG. 2 (a). (A) is a cross-sectional view of a main part of a tunnel during a support installation process following FIG. 2, and (b) is an enlarged cross-sectional view of a region A1 surrounded by a broken line in FIG. 3 (a). (A) is a front view of a main part when the area A2 surrounded by the broken line in FIG. 3 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and (b) is a cross section of the line I-I in FIG. 4 (a). It is a figure. (A) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 3, and (b) is an enlarged cross-sectional view of the region A1 surrounded by the broken line in FIG. 5 (a). (A) is a front view of a main part when the area A2 surrounded by the broken line in FIG. 5 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and (b) is a cross section of the line I-I in FIG. 6 (a). It is a figure. (A) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 5, and (b) is an enlarged cross-sectional view of the area A2 surrounded by the broken line in FIG. 7 (a). (A) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 7, and (b) is an enlarged cross-sectional view of the area A2 surrounded by the broken line in FIG. 8 (a). (A) is a front view of a main part when the area A2 surrounded by the broken line in FIG. 8 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and (b) is a cross section of the line I-I in FIG. 9 (a). It is a figure. (A) is a front view of a main part when the area A3 surrounded by the broken line in FIG. 8 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and (b) is a cross section of line II-II in FIG. 10 (a). It is a figure. (A) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 8, and (b) is an enlarged cross-sectional view of the area A3 surrounded by the broken line in FIG. 11 (a). (A) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 11, and (b) is an enlarged cross-sectional view of the area A3 surrounded by the broken line in FIG. 12 (a). (A) is a front view of the main part when the area A3 surrounded by the broken line in FIG. 12 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and (b) is a cross section of the line II-II in FIG. 13 (a). It is a figure. (A) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 12, and (b) is an enlarged cross-sectional view of the area A3 surrounded by the broken line in FIG. 14 (a). It is sectional drawing of the main part of the tunnel during the support construction installation process following FIG.

Hereinafter, embodiments as an example of the present invention will be described in detail with reference to the drawings. In addition, in the drawing for demonstrating the embodiment, the same components are in principle the same reference numerals, and the repeated description thereof will be omitted.

An example of the installation method of the support work of the present embodiment will be described with reference to FIGS. 1 to 15. In the cross-sectional view of the tunnel, the right side of the center line CL in the width direction (diameter direction) of the tunnel is symmetrical with the left side of the center line CL and has the same configuration as the left side. The illustration is omitted.

First, FIG. 1 (a) is a cross-sectional view of a main part intersecting in the longitudinal direction of the tunnel during the support installation process according to the present embodiment, and FIG. 1 (b) is a region A1 surrounded by a broken line in FIG. 1 (a). It is an enlarged sectional view of. Here, the upper tunnel T1 having a substantially semicircular cross section is formed by excavating the ground G by a blasting method or the like.

Subsequently, FIG. 2A is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 1, and FIG. 2B is an enlarged cross-sectional view of the region A1 surrounded by the broken line in FIG. 2A. .. Here, in order to strengthen the tunnel T1, concrete or the like is sprayed on the inner surface of the tunnel T1 to form the concrete layer C1. The concrete layer C1 may not be formed.

Subsequently, FIG. 3 (a) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 2, and FIG. 3 (b) is an enlarged cross-sectional view of the region A1 surrounded by a broken line in FIG. 3 (a). 4 (a) is a front view of the main part when the area A2 surrounded by the broken line in FIG. 3 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and FIG. 4 (b) is I-I in FIG. 4 (a). It is sectional drawing of a line.

Here, the upper support member (first support member) 10 is installed in the upper tunnel T1. The upper support member 10 is made of, for example, H steel, and is formed in an arch shape when viewed from the front, for example. That is, the upper support member 10 extends from the ceiling of the upper tunnel T1 along both inner side surfaces and ends at the bottom surface of the upper tunnel T1.

As shown in FIG. 4, a connecting plate (first connecting plate) 11 intersecting the extending direction of the supporting member 10 is joined to the lower end surface of the leg portion of the upper supporting member 10. ing. The connection plate 11 is perforated with two bolt holes (first bolt holes) 12 penetrating between the upper and lower surfaces in the thickness direction. Further, on the connecting plate 11, two bag nuts (first bag nuts) 13 are joined symmetrically with the bolt holes 12 and the nut holes 13a aligned. A female screw (not shown) is formed on the inner surface of the nut hole 13a of the bag nut 13.

Next, FIG. 5 (a) is a sectional view of a main part of the tunnel during the support installation process following FIG. 3, FIG. 5 (b) is an enlarged sectional view of the region A1 surrounded by the broken line of FIG. 5 (a), and FIG. (A) is a front view of a main part when the area A2 surrounded by the broken line in FIG. 5 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and FIG. 6 (b) is the line I-I of FIG. 6 (a). It is a cross-sectional view of.

Here, concrete or the like is sprayed onto the inner surface of the tunnel T1 including the surface of the upper support member 10 to form the concrete layer (first concrete) C2. As shown in FIG. 6, the surface of the upper support member 10 is sufficiently covered with the concrete layer C2 including the outer circumference of the bag nut 13. Although FIG. 6A is a front view, the concrete layer C2 is hatched to make the drawing easier to see.

Subsequently, FIG. 7A is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 5, and FIG. 7B is an enlarged cross-sectional view of the region A2 surrounded by the broken line in FIG. 7A. .. Here, the ground under the upper tunnel T1 is excavated to form the lower excavation area T2 under the tunnel T1.

Next, FIG. 8 (a) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 7, FIG. 8 (b) is an enlarged cross-sectional view of the region A2 surrounded by a broken line in FIG. 8 (a), and FIG. (A) is a front view of a main part when the area A2 surrounded by the broken line in FIG. 8 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and FIG. 9 (b) is the line I-I of FIG. 9 (a). 10 (a) is a front view of a main part when the area A3 surrounded by a broken line in FIG. 8 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and FIG. 10 (b) is a front view of the main part. ) Is a cross-sectional view taken along the line II-II.

Here, first, as shown in FIG. 8, concrete or the like is sprayed on the inner surface of the lower excavation area T2 to form the concrete layer C3 in order to strengthen the lower excavation area T2. The concrete layer C3 may not be formed.

Subsequently, the lower support member (second support member) 20 is installed under both legs of the upper support member 10 in the lower excavation area T2. The lower support member 20 is made of, for example, H steel, extends from below both legs of the upper support member 10 along the inner surface of the lower excavation area T2, and at the bottom surface of the lower excavation area T2. It is terminated.

As shown in FIG. 9, a connecting plate (second connecting plate) 21 intersecting the extending direction of the supporting member 20 is joined to the upper end surface of the lower supporting member 20. The connection plate 21 is perforated with two bolt holes (second bolt holes) 22 penetrating between the upper and lower surfaces in the thickness direction. In the lower support member 20, the bolt holes 22 of the two upper connection plates 21 are aligned with the bolt holes 12 of the lower two connection plates 11 of the upper support member 10, and the lower support member 20 is provided. It is installed under the upper support member 10 in a state where the upper connection plate 21 of the member 20 is in contact with the lower connection plate 11 of the upper support member 10.

Further, as shown in FIG. 10, a connecting plate (third connecting plate) 23 intersecting the extending direction of the supporting member 20 is joined to the lower end surface of the lower supporting member 20. There is. The connection plate 23 is perforated with two bolt holes (third bolt holes) 24 penetrating between the upper and lower surfaces in the thickness direction. Further, two bag nuts (second bag nuts) 25 are joined on the connection plate 23 with the nut holes 25a aligned with the bolt holes 24. A female screw (not shown) is formed on the inner surface of the nut hole 25a of the bag nut 25.

After installing the lower support member 20 under both legs of the upper support member 10 as described above, as shown in FIG. 9, a bolt hole is provided from the back surface side of the connection plate 21 of the lower support member 20. Through 22 and 12, individual bolts (first bolts) 26 are screwed into individual bag nuts 13 on the connecting plate 11 of the upper support member 10. As a result, the upper support member 10 and the lower support member 20 are connected. A male screw is formed on the outer circumference of the bolt 26.

Here, normally, the upper support member 10 and the lower support member 20 are connected by bolts and nuts, but before the connection work, the surface of the upper support member 10 is the concrete layer C2. Since it is covered with, the upper and lower support members 10 and 20 cannot be connected to each other.

Therefore, usually, before installing the lower support member 20, the portion corresponding to the connection portion with the lower support member 20 in the concrete layer C2 covering the surface of the upper support member 10 is scraped off, so-called chipping. Before performing the work or covering the surface of the upper support member 10 with the concrete layer C2, cover the connection portion with the lower support member 20 on the surface of the upper support member 10 with a box-shaped member. We are doing so-called box removal work.

However, the above-mentioned chipping work and box removal work are troublesome work that requires time and labor, and there is a problem that the efficiency of the installation work of the support work is lowered. Further, in the case of the chipping work, the support member 10 may be damaged during the work, or the looseness of the ground G may be increased due to the vibration during the work. On the other hand, in the case of box removal work, filling failure of the concrete layer C2 may occur at the box removal location.

On the other hand, in the present embodiment, since neither the chipping work nor the box removal work can be eliminated, the efficiency of the installation work of the support work can be improved. Therefore, the construction period in the tunnel construction can be shortened and the construction cost can be reduced. Moreover, since the chipping work is not performed, the problem of damage to the support member 10 and the problem of increasing the looseness of the ground G do not occur. Further, since the box removal work is not performed, the problem of poor filling of the concrete layer 2 does not occur. Therefore, the reliability of tunnel construction can be improved.

Subsequently, FIG. 11A is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 8, and FIG. 11B is an enlarged cross-sectional view of the region A3 surrounded by the broken line in FIG. 11A. .. Here, concrete or the like is sprayed onto the inner side surface of the lower excavation area T2 including the inner side surface of the lower support member 20 to form a concrete layer (second concrete) C4. In this case as well, as shown in FIG. 6, the surface of the lower support member 20 is sufficiently covered with the concrete layer C4 including the outer circumference of the bag nut 25.

After such concrete spraying work, assuming that the ground of the ground G is weak, the ground under the lower excavation area T2 is excavated and the excavation area T3 for invert installation is formed under the lower excavation area T2. Form.

Next, FIG. 12 (a) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 11, and FIG. 12 (b) is an enlarged cross-sectional view of the region A3 surrounded by the broken line of FIG. 12 (a). (A) is a front view of a main part when the area A3 surrounded by the broken line in FIG. 12 (a) is viewed from the center of the tunnel toward the inner surface of the tunnel, and FIG. 13 (b) is the line II-II of FIG. 13 (a). It is a cross-sectional view of.

Here, first, concrete or the like is sprayed on the inner side surface and the bottom surface of the excavation area T3 for invert installation to form the concrete layer C5. The concrete layer C5 may not be formed.

Subsequently, in the excavation area T3 for invert installation, the invert support member (third support member) 30 is installed under both legs of the lower support member 20. The support member 30 for invert is made of, for example, H steel, and is formed in an inverted arch shape so as to bridge the legs from below both legs of the lower support member 20.

As shown in FIG. 13, a connecting plate (fourth connecting plate) 31 intersecting the extending direction of the supporting member 30 is joined to the upper end surface of the supporting member 30 for inverting. The connection plate 31 is perforated with two bolt holes (fourth bolt holes) 32 penetrating between the upper and lower surfaces in the thickness direction. The support member 30 for invert aligns the two bolt holes 32 of the connection plate 31 at the upper part with the two bolt holes 24 of the connection plate 23 at the lower part of the support member 20 on the lower side, and supports the support for invert. It is installed under the lower support member 20 in a state where the upper connection plate 31 of the work member 30 is in contact with the lower connection plate 21 of the lower support member 20.

After installing the support member 30 for invert under both legs of the lower support member 20 as described above, as shown in FIG. 13, bolts from the back surface side of the connection plate 31 of the support member 30 for invert. Individual bolts (second bolts) 33 are screwed into the individual bag nuts 25 on the connecting plate 21 of the lower support member 20 through the holes 32 and 24. As a result, the lower support member 20 and the support member 30 for invert are connected.

In this case as well, since the above-mentioned chipping work and box removal work can be eliminated, the efficiency of the installation work of the support work can be improved. Therefore, the construction period in the tunnel construction can be shortened and the construction cost can be reduced. Moreover, since the chipping work is not performed, the problem of damage to the support member 20 and the problem of increasing the looseness of the ground G do not occur. Further, since the box removal work is not performed, the problem of poor filling of the concrete layer C4 does not occur.

Subsequently, FIG. 14 (a) is a cross-sectional view of a main part of the tunnel during the support installation process following FIG. 12, and FIG. 14 (b) is an enlarged cross-sectional view of the region A3 surrounded by a broken line in FIG. 14 (a). 15 is a cross-sectional view of a main part of the tunnel during the support installation process following FIG.

Here, first, as shown in FIG. 14, a concrete layer (third concrete) is formed by spraying concrete or the like on the inner surface and the bottom surface of the excavation area T3 for invert installation including the inner surface of the support member 30 for invert. Form C6. In this way, the support S provided with the support members 10, 20, and 30 is installed in the tunnel T.

Subsequently, as shown in FIG. 15, after the base member 40 made of concrete or the like is placed in the excavation area T3 for invert installation, a concrete wall is formed on the inner surface of the tunnel T by using a semi-cylindrical metal formwork or the like. Form C7.

Although the invention made by the present inventor has been specifically described above based on the embodiments, the embodiments disclosed in the present specification are exemplary in all respects and are limited to the disclosed techniques. It's not a thing. That is, the technical scope of the present invention is not limitedly interpreted based on the description in the above-described embodiment, but should be interpreted only in accordance with the description of the claims, and the scope of claims. All changes are included as long as they do not deviate from the description technology and the technology equivalent to the above and the gist of the claims.

For example, in the above-described embodiment, the case where the support member for invert is provided has been described, but when the ground is strong or the like, the support member for invert may not be provided.

The present invention is effective when applied to a technique for connecting members of a support work in a tunnel.

10 Upper support member 11 Connection plate 12 Bolt hole 13 Bag nut 13a Nut hole 20 Lower support member 21 Connection plate 22 Bolt hole 23 Connection plate 24 Bolt hole 25 Bag nut 25a Nut hole 26 Bolt 30 Support member 31 Connection plate 32 Bolt hole 33 Bolt 40 Base member G Ground T Tunnel T1 Upper tunnel T2 Lower excavation area T3 Excavation area C1 to C6 Concrete layer C7 Concrete wall S Support

Claims (4)

A first support member that extends from the ceiling to the middle of the side along the inner surface of the tunnel,
A first connecting plate provided on the lower end surface of the first support member so as to intersect the extending direction of the first support member.
The first bolt hole drilled in the first connecting plate and
With the first bag nut joined on the first connecting plate with the nut hole aligned with the first bolt hole,
The first concrete sprayed so as to cover the inner surface above the lower end of the first support member including the first bag nut,
A second support member extending downward from the lower end surface of the first support member, and
A second connecting plate provided on the upper end surface of the second supporting member in a state of intersecting the extending direction of the second supporting member and in contact with the first connecting plate.
A second bolt hole drilled at a position facing the first bolt hole in the second connection plate, and a second bolt hole.
Through the first bolt hole and the second bolt hole, it is screwed into the first bag nut via the first connecting plate and the second connecting plate, and is screwed into the first support member. The first bolt connecting the second support member and
A second concrete sprayed so as to cover the inner surface above the lower end of the second support member including the first bolt, and
The structure of the timbering in the tunnel, which is characterized by being equipped with. A third connecting plate provided on the lower end surface of the second support member so as to intersect the extending direction of the second support member.
A third bolt hole drilled in the third connecting plate and
A second bag nut joined on the third connecting plate with the nut hole aligned with the third bolt hole,
The second concrete sprayed so as to cover the inner surface above the lower end of the second support member including the second bag nut.
A third support member provided in a state of bridging these between the legs of the second support member on both side surfaces in the width direction of the tunnel, and
A fourth connecting plate provided on the upper end surface of the third supporting member in a state of intersecting the extending direction of the third supporting member and in contact with the third connecting plate.
A fourth bolt hole drilled at a position corresponding to the third bolt hole in the fourth connection plate, and a fourth bolt hole.
Through the third bolt hole and the fourth bolt hole, it is screwed into the second bag nut via the third connecting plate and the fourth connecting plate, and is screwed into the second support member. A second bolt connecting the third support member and
A third concrete sprayed so as to cover the inner surface of the third support member including the second bolt, and
The structure of the support work in the tunnel according to claim 1, further comprising. (A) A step of excavating a ground to form an upper tunnel, and installing a first support member extending from the ceiling along the inner surface of the tunnel and terminating at the bottom surface of the tunnel.
(B) A step of spraying the first concrete onto the inner surface of the tunnel including the inner surface above the lower end of the first support member.
(C) After the step (b), a step of excavating the ground below the leg of the first support member to form a lower excavation area, and
(D) A third that extends from the lower end surface of the first support member to the side surface of the lower excavation region on the lower side of the leg of the first support member and terminates at the bottom surface of the lower excavation region. The process of installing the support member of 2 and
(E) A step of connecting the first support member and the second support member, and
(F) After the step (e), a step of spraying the second concrete onto the inner surface of the lower excavation area including the inner surface above the lower end of the second support member.
Have,
A first connecting plate that intersects the extending direction of the first supporting member is provided on the lower end surface of the first supporting member, and is provided on the first connecting plate. , The first bag nut is joined with the nut hole aligned with the first bolt hole drilled in the first connection plate.
A second connecting plate that intersects the extending direction of the second supporting member is provided on the upper end surface of the second supporting member, and the first connecting plate is provided in the second connecting plate. A second bolt hole is drilled at a position facing the bolt hole of
In the step (d), the second bolt hole of the first connection plate of the first support member is inserted into the second bolt hole of the second connection plate of the second support member. It has a step of aligning the bolt holes and installing the second support member in a state where the second connection plate is in contact with the first connection plate.
In the step (e), the first bolt is screwed into the first cap nut from the lower surface side of the second connecting plate through the second bolt hole and the first bolt hole. A method for installing a support in a tunnel, which comprises a step of connecting the first support member and the second support member. (G) After the step (f), a step of excavating the ground below the leg of the second support member to form an excavation area for invert.
(H) A step of installing the third support member in the excavation area for invert on the lower side of the leg of the second support member.
(I) A step of connecting the second support member and the third support member, and
(J) A step of spraying the third concrete on the inner surface of the invert excavation area including the inner surface of the third support member.
Have,
A third connecting plate that intersects the extending direction of the second supporting member is provided on the lower end surface of the second supporting member, and is provided on the third connecting plate. , The second bag nut is joined with the nut hole aligned with the third bolt hole drilled in the third connection plate.
A fourth connecting plate that intersects the extending direction of the third supporting member is provided on the upper end surface of the third supporting member, and the third connecting plate is provided with the third connecting plate. A fourth bolt hole is drilled at a position facing the bolt hole of
In the step (h), the third bolt hole of the third connecting plate of the second support member is aligned with the fourth bolt hole of the fourth connecting plate, and the third bolt hole is aligned with the third bolt hole. It has a step of installing the third support member in a state where the fourth connection plate is in contact with the connection plate.
In the step (i), the second bolt is screwed into the second cap nut from the lower surface side of the fourth connecting plate through the fourth bolt hole and the third bolt hole. The method for installing a support in a tunnel according to claim 3, further comprising a step of connecting the second support member and the third support member.

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